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Welcome to the world of geology!

Introduction to Geology (PHYS-258, 2 credits)

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Review Quizzes

Introduction to Geology and Soil Mechanics

(PHYS-257, 3 credits)

Syllabus

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Geology Topics For Construction Review Quizzes

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Welcome to Dr. Scott's Geology Home Page!

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 1 Introduction Jump to: Lecture Notes

Historical Development Jump to: Lecture Notes, Web Links

Geologic Time Jump to: Lecture Notes (Geologic Time Chart, Local History, Dating Techniques, Radon), Web Links

Review Quizzes

Introduction Introduction - Lecture Notes

What do the following items have in common?

Limestone Dolomite Perlite Mica Gypsum Attapulgite Kaolin Halite Clay Nickel Cadmium Graphite Silica, (Alkaline Silica) Quartz

Diamond Aluminum Silicate Coal Tar Crystalline Silicate Americium 241 - Radioactive Calcium Sulfate Titanium Dioxide Copper Talc Zinc Lava Rock (Landscaping Rocks, etc.) Industrial Quartz

Answer

These are ingredients found in products at Fleet/Farm in Menomonie, WI. Of course, think of all the products containing steel, aluminum, and brass. (not a complete ingredient list):

Sheetrock Patching Compound: plaster of paris, limestone, dolomite, expanded perlite, mica, attapulgite, kaolin Salt Bricks: Halite Detergent: sodium silicate Sandpaper: sand and gravel Smoke Detector: 1 microcurie of Americium 241 (radioactive)

Flashlight: nickel, cadmium Glass Cleaner: Silica Stove Gasket: graphite impregnated fiberglass Stove Motar: alkaline silicate Black Top Sealer: refined coal tar, hydrous aluminum silicate, water (and fatty acid) Note: Coal tar is a phototoxic substance which, in the presence of sunlight, can cause a skin reaction similar to an aggravated sunburn, frequently causing blisters. Coal tar and benzo(a) pyrene containing polycyclic aromatic hydrocarbons have been determined to be human carcinogens.

Vinyl siding wash: sodium hypochlorite, sodium metasilicate Roof Coating: aluminum flake, amorphous siliceous mineral, calcium carbonate, magnesium carbonate, silicic acid Crack Filler: quartz, calcium sulfate, biocides Plaster Additive: crystalline silicate Construction Adhesive: crystalline silicate, calcium carbonate Premium F&F House and Trim Satin: titanium dioxide Primer Latex: talc, mica, zinc oxide pigment, silicon dioxide Weatherbond Barn and Fence: clay, CaCO3, TiO2, crystalline silica Copper Wires, Quartz Halogen Lights Tile Cutting Wheel: Diamond impregnated wheel Landscaping stones: lava rocks, etc. Sand Blasting: industrial quartz, sand (silica) Livestock additive: cobalt carbonate, magnesium oxide, (many oxides), phosphorus and salt Cargill Trace Mineral Salt: Zn, Mg, Fe, Cu, I, Co

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The "big picture"

Geology is generally divided into physical geology and historical geology.

Physical geology is the study of physical processes that occur on earth and the material composition of the earth. In recent times, these physical principles have been used to study other terrestrial planets within our solar system.

Historical geology examines the time evolution of material structures and life on earth. This examination focuses on layered rock records and fossils.

Just about everything we encounter (including ourselves) are derived from the earth. The tough question is "What is not related to geology?"

The other part of this course focuses on soil (only for PHYS-257). Soil Mechanics is a study of the engineering properties. How does soil respond to external forces?

It is instructive to make a short excursion into discussing the scientific method of investigation. In short:

In long: 1. Define a problem or make an observation. 2. Hypothesize a theory to describe or explain observation. 3. Test the theory. Can it predict anything? Is it reproducible? 4. Can others reproduce the results and make the same conclusions? 5. Modify or discard theory if steps 3 and 4 are unsuccessful. Go back to step 1. 6. If it is consistently reproducible and almost all of the scientific community agrees with the theory, it becomes a natural law. One should view natural laws and theories as "works in progress" to which some laws and theories are stronger than others. Stronger in the sense of reproducibility and predictive power.

Two forms of logical reason form the basis of most scientific thought. For deductive reasoning, if the premises are true, then the conclusion has to be true. Such that,

If all ford trucks built in '76 have seat belts and Ted's ford truck was built in '76, then Ted's truck has a seat belt (or, at least, originally had a seatbelt if it wasn't removed).

For inductive reasoning, no matter how much evidence exists for a conclusion, the conclusion could still conceivably be false.

Suppose someone eats 5 apples out of a barrel of 100 and finds each of the 5 apples to be tasty. From this, they conclude that all the apples are tasty.

One can have weak or strong inferences based upon inductive reasoning. Many "scientific" studies are plagued with the problem of distinguishing between a causation verses a correlation. This seems to be most true in the field of sociological studies. The field of geology has many principles based upon inductive reasoning.

For more reading, here is a study guide to scientific findings published in the New York Times. An Introduction to Science - Dr. Steven D. Schafersman, Miami University Introduction, Earth Formation, and Natural Sciences - Lecture Notes, Dr. Susan DeBari, SJSU Google - Search for Physical Geology Lecture Notes

Historical Development Historical Development - Lecture Notes

When did geology begin to establish a scientific foundation?

If we go back 2 or 3 centuries, we would find that most people (including scholars) had a very poor understanding of the age of the earth. Compounding this problem was a tendency to

attribute unusual observations to divine intervention or catastrophism. Such that, sedimentation rock layers 10,000 feet into the air were observed to contain fossils of organisms that lived underwater. This was difficult to rectify with current earth processes if one assumes the earth to be relatively young (~10,000 years).

Archbishop James Ussher (1581-1656) studied history and biblical text to determine that the earth was created on Sunday, October 23, 4004 BC. Adam and Eve were driven from Paradise on Monday, November 10, 4004 BC and the Ark touched down on Mt. Ararat on Wednesday, May 5, 1491 BC. A scientific analysis of geology indicates this to be complete folly.

A Scottish medical man, gentlemen farmer, and geologist named James Hutton is credited with putting modern geology onto a scientific footing. In the late 1700's he published a paper entitled Theory of the Earth With Proofs and Illustrations".

● He wrote "We find no sign of a beginning - no prospect for an end." ● He put forth the principle of Uniformitarianism which states that the physical processes operating in the present to modify the earth's surface also operated in the geologic past.

In other words, "The present is key to the past."

Historical Development - Related Web Links

An Introduction to Geology For Ordinary Folks by Terry Wright A short biography of James Hutton Google - Search for Historical Geology Lecture Notes

Geologic Time Geologic Time - Lecture Notes

"Nobody hurries geology" - Mark Twain

"[People] cling to the edge of eternity our passion to know propels us to the stars but we are humbled by the secrets of the earth. Is this great canyon the work of God or a symphony of nature? Is it the summation of all grandeur or the grave of the world?"

- Grand Canyon: The Hidden Secrets, (Destination Cinema), 2002, DVD IMAX movie

Animation of Geologic Time

The Earth solidified and became a planet about 4.6 billion years ago. Geologist have subdivided this 4.6 billion years into Eons, Eras, and Periods. These divisions are based upon

major trends in the evolution of life on earth according to fossil records. In particular, the boundaries between the geologic eras represent times where mass extinctions have occurred.

Geologic Time

(Click on a box to see fossil records and information about that time in earth's history.)

Phanerozoic means visible life (Greek origin). Cenozoic means recent life. Also called the "Age of the Mammals". Mesozoic means middle life. Also called the "Age of the Reptiles" or "Age of the Dinosaurs". Paleozoic means ancient life. Also called the "Age of the Fish". (Be careful, just because the Paleozoic era is called the age of the fish doesn't mean there were no fish in the Mesozoic era. And early humans did not exist during the reign of the dinosaurs. Hollywood sometimes depicts humans with dinosaurs as in the "Land Before Time".)

Paleontologists working at the Mammoth Site dig site in Hot Springs, South Dakota. A mammoth tusk is

being uncovered in the foreground. The fossils at this site date back to about 26,000 years.

Tyrannosaurus Skull

66 Million Years Ago, Cretaceous (The size of this skull grew to about 1.46 m or about 5 feet long.)

The era are bounded by profound changes in world-wide life forms. Plus, the furthur back one goes the more limited our knowledge becomes. It is important to note that when the "early paleozoic" time is discussed, the term "early" means "older". The term "late paleozoic" time implies "young" or an age of about 260 million years old.

The Cambrian period represents the first clear and recognizable fossil records of life. However, scientist have evidence supporting the existence of simple life forms (such as bacteria) going back over 3 billion years ago. A detailed description of this boundary between the cambrian period and pre-cambrian time can be found here.

A good mnemonic device for remembering the sequence of periods is "Quit Telling Crazy Jack That Perry Como Died Slowly Over Coals."

"...The earth scorns our simplifications, and becomes much more interesting in its derision. The history of life is not a continuum of development, but a record punctuated by brief, sometimes geologically instantaneous, episodes of mass extinction and subsequent diversification. The geologic time scale maps this history, for fossils provide our chief criterion in fixing the temporal order of rocks...Hence, the time scale is not the devil's ploy for torturing students, but the chronicle of key moments in life's history...I make no apologies for the central importance of such knowledge." [source: Gould, S.J., 1989, Wonderful Life, W.W. Norton and Co.]

Local History

The surface of the earth observed today represents a complex series of geological events that began ~4.6 billion years ago. Wisconsin has two major physical provinces (areas with similar geology): Canadian Shield and Stable Continental Interior. Northern Wisconsin (or Southern Canadian Shield) area is call the Superior Upland Province and is mostly metamorphic and igneous rocks of Pre-cambrian age. It has been subjected to folding, faulting, and igneous activity. Southern Wisconsin (or Northern Stable Interior) is called the Central Lowlands Province. It is flat or gently folded sedimentary strata of paleozoic or younger age.

Dating Techniques (Radioactive and Non-radioactive)

Non-radioactive: Tree Rings (Bristlecone Pine > 4,000 years old), Rock Strata, Astronomy (Hubble's Law, Star Clusters), Electron Spin Resonance, Thermoluminescence (radiation changes to rock crystals), Mitochondrial DNA (mutation rate), Amino Acid analysis (gradual change)

[Tree Ring research - or Dendrochronology - has enabled a continuous record of earth's climatic history dating back 8,000 years.]

Sitka Spruce Tree in Olympic National Park (WA) that is about 500 years old.

Cross section of a tree that was about 500 years old when fell. This section of it shows the rings for about 250 years. (This tree grew in Olympic National Park.)

The configuration of rock strata can give an indication of relative age. The principle of superposition can be stated as follows: In a sequence of strata (i.e. sedimentary rocks or lava flows) that have not been overturned by crustal deformation, the older layers are on the bottom and the youngest are on the top. If an igneous rock unit in the form of a dike, stock, or batholith cuts across another rock, the igneous rock unit is said to have a cross-cutting relationship to the other rock and is younger. The study of fossils also provides a means of determining the relative ages of the strata in which fossils occur.

Some Terminology in Dating Rock Strata: Unconformity represents a period where deposition occurred, then ceased and erosion began, then erosion stopped and deposition resumed. Uplift may also play a role. Here are some specific types of unconformities:

Angular Unconformity is an unconformity with the deeper sedimentary rock layers tilted with respect to the overlain, flatter lying strata. Disconformity is an unconformity with the deeper sedimentary rock layers parallel with the overlain rock layers. This unconformity is difficult to identify. Nonconformity represents a break between older metamorphic or igneous rocks with younger sedimentary rocks overlaying them.

Example of Relative Dating

By applying the relative dating principles, the rock strata in this profile can be relative dated and unconformities can be identified. Try to relative age date these strata and identify at least one unconformity. After attempting this exercise on your own, click here for the solution.

Radioactive (or Radiometric Dating)

Some naturally occuring nuclei within atoms are unstable. Such that, the nuclei are in a quantum mechanical energy state that will spontaneously decay (by photon or particle emission) over time into a more stable energy state. How quickly a radioactive nuclei decays depends on its half-life. Half of the original nuclei will remain un-decayed after one half-life of time has transpired.

where T is the half-life of the parent nuclei, No is the original number of parent nuclei, N is the number of un-decayed nuclei. This can also be expressed as

where

.

An absolute age of some rocks or fossils can be determined based on the radioactive decay of certain elements. To determine the age of a given mineral or rock, the amount of "parent" to "daughter" atoms need to be carefully measured along with the decay rate of the parent (and the daughter if it is also radioactive). Igneous rocks and minerals, when dated, give the age of crystallization (or solidification). Metamorphic rocks can sometimes cause inaccurate radioactive dating due to the removal of daughter atoms. The longer the half-life of the parent, the older the rock is that can be dated.

[Note: The atomic elements are usually denoted as with A being the atomic mass or atomic weight (equal to the number of protons plus neutrons in the nucleus), Z is the atomic

number (equal to the number of protons in the nucleus). The Z must be consistent with the abbreviation of the element, El. For example, is carbon 14 (an isotope of carbon 12). Isotopes have the same Z (or element name) but a different A. ]

Carbon 14 Dating

Perhaps the best known radioactive dating is based on . This is used to date organic remains. The ratio of to remains constant in an organism as it lives. Upon dying, the

begins to decay into but the amount of remains constant. Therefore, an accurate measurement of the ratio of their amounts gives an age. Since has a relatively short

half-life of 5,730 years, this method is accurate for ages less than about 60,000 years. The ratio of in living organisms is 1.2x10-12 (source: Physics Education, March 2004, p. 137).

Radon Fact Sheet For Construction

All about radiation and risk analysis. (No hypochondriacs allowed into this link! Everything you wanted to know about radiation and quantifying risk but were afraid to ask.)

Geologic Time - Related Web Links

Radiometric Dating of Rocks (USGS) On-line "Geological Time Machine" USGS On-line book Geologic Time by William L. Newman

USGS On-line book FOSSILS, ROCKS, AND TIME By Lucy E. Edwards and John Pojeta, Jr. Natural History Museums Grand Canyon Explorer Radiometric Dating of Rocks and Isotopes, History of Radiation Other Geologic Time Charts - University of Calgary, Geology and Geologic Time from UC-Berkeley, YOGI's Geologic Time Chart Stephen Gould on evolution An on-line book with a detailed analysis of the teaching of Creationism verses Evolution debate (National Academy Press) Geology of Mt. Diablo - I (instructor of this course) used to live nearby this Mountain Tunguska impact in Siberia (1908) - One of the strangest natural events recorded in recent times. Google - Search for Radioactivity Animations Google - Search for Geologic Time

Human Origins - A site devoted to exploring human origins

"The Smithsonian Barbie" (humor) On-line Lecture Notes

GOOGLE search for lecture notes on geologic time Dr. Pamela Gore's On-line course in Historical Geology (geologic time, evolution, etc.) and Radiometric Dating Dr. Susan DeBari, lecture notes on Earth Structure and Geologic Time Dr. Susan DeBari, lecture notes on Geologic Time and Relative Dating Dr. Tom Clifton, lecture notes on History of Life Google - Search for Geologic Time Lecture Notes

Review Quizzes Section 1

Review Quiz Section 1 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapters Introduction To Geology or Geologic Time or Earth History: A Brief Summary)

Grand Canyon, 1991

To see a schematic of the age of each rock strata in this picture go to the PBS web site Lost in The Grand Canyon, The American Experience.

(Click to enlarge)

Grand Canyon art (Click to enlarge)

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 2 Rock Cycle Jump to: Lecture Notes (review atomic theory, Rock Cycle), Web Links

Minerals Jump to: Lecture Notes (physical properties, Groupings), Web Links

Raw Materials Jump to: Lecture Notes (Energy, Mining, Raw materials in construction), Web Links

Review Quizzes

Rock Cycle Rock Cycle - Lecture Notes

(Review) Atomic Theory

Each atom is made up of an outer shell of electrons and a heavy nucleus containing protons and neutrons. They are referred to with the following notation.

If the size of the nucleus were equivalent to a tennis ball (r~3.5cm), then the electrons would be in orbit at a distance of 1.5 km! If this tennis ball were entirely composed of carbon atoms and had a mass of 50 grams, then it would contain about 2.5x1024 atoms or

2,500,000,000,000,000,000,000,000.0 atoms.

Compare this to the estimated number of people on the planet of 5,000,000,000.0 people.

Quantum mechanics tells us how the electrons behave in "orbit" around the nucleus. All the chemical properties (i.e. combine and react with other elements) of that element are governed by the "configuration" of electrons . Examples: Dynamite releases stored chemical energy contained in the bonds between elements and molecules. Plant photosynthesis occurs via a complex set of reactions involving energy, light, and chemicals. Just about everything we encounter in everyday life is a result of chemical reactions and bonding between elements.

Types of Chemical Bonds Covalent Bonding - Very strong, shares the outer shell electrons. (e.g. Diamond) Ionic Bonding - One atom loses a charge (e-) and another gains one, medium strength. (e.g. NaCl) ~90% of all minerals have ionic bonding Van Der Waals Bonding - Weakest bond, results from a slight polarization in the atoms. Metallic Bonding - (a form of covalent bonding) Allows electrons to "freely" move from one atom to another, usually good thermal and electrical conductors.

There are 14 ways in which atoms can "fit" together to fill all of space. These are called lattice types.

What is a mineral? For something to be classified as a mineral it must satisfy these criteria: 1. It is an inorganic, naturally occurring element or compound in a solid state. (It is disputed whether naturally occurring liquids at room temperature, e.g. water and mercury, should be considered a mineral.) 2. It has a composition that is fixed or varies within narrow limits. 3. It has a characteristic crystalline structure.

What is a rock? A rock is just an assemblage of one or more minerals. A typical rock may vary considerably in mineral composition.

Rocks are divided into 3 major groups

● Igneous rocks are formed by the cooling of magma (below the surface) or lava (above the

surface). These rocks are the ancestors of all rocks.● Sedimentary rocks are made up of particles derived from the breakdown of pre-existing rocks.

Lithification is the process that changes unconsolidated deposits into rock.● Metamorphic rocks have changed their form due to exposure to pressure, heat, and/or

chemically active fluids.

The Rock Cycle describes the relationship between these three categories of rocks.

Rock Cycle (Click on the rocks)

The arrows indicate a change in the environment.

Rock Cycle - Related Web Links

GOOGLE search for Rock Cycle Rock Cycle from U. of Texas at El Paso, Rock Cycle from the University of Saskatchewan Dept. of Geological Sciences Rock Cycle from the course Introduction to Petrology, University of British Columbia Information Guide on rock collecting from the USGS Google - Search for Rock Cycle

Minerals Minerals - Lecture Notes

There exists over 4,000 different minerals that have been classified. Some of these minerals are much

more abundant than others.

Just 10 elements make up 99% (by weight) of the Earth's crust. These are O, Si, Al, Fe, Ca, Na, K, Mg, Ti, H. Most (74.3%) of the minerals in the Earth's crust contain Oxygen (O) and Silicon (Si). This is why the Silicate mineral family (minerals having the ion SiO4) compose 90% of all rock forming

minerals.

Minerals can be identified by

● Using X-ray diffraction (determines crystal structure) and mass spectrometry (determines composition)

or

● examining the physical, macroscopic properties of the mineral.

Suppose you are excavating for a residential basement and find a very shiny and interesting rock. Is it worth anything and what is it? Your tool shed probably does not have an x-ray diffraction device or a mass spectrometer. Thus, the physical properties that one can identify with the unaided eye and a few simple tools becomes useful.

Physical Properties of Minerals

Crystal Form (or Habit) is the external shape produced by a minerals internal crystalline structure. This happens when a mineral grows (or solidifies) without interference or obstacle. It will be bounded by planar surfaces symmetrically arranged.

Cleavage is the tendency of a mineral to break in certain preferred directions along smooth planes.

Twinning is the intergrowth of two or more single crystals of the same mineral with different geometric orientations.

Striations are parallel, threadlike lines or narrow bands running across crystal faces or cleavage surfaces.

Hardness is determined by the relative ease or difficulty with which one mineral can scratch another. (A characteristic determined by the internal atomic arrangements and chemical bonding.) Using known mineral samples to test the hardness of an unknown is common practice.

Mohs Hardness Scale (This scale is not "linear". Such that, a hardness of 2 might be twice as hard as 1, but 5 might be 10

times the hardness of 1 on Mohs scale.)

Specific Gravity is, essentially, the minerals density when compared to the density of water.

[Information that may be useful: In the SI system of units (metric system), weight has units of Newtons (N) and mass has units of Kilograms (kg). In the "Old English" system, weight has units of Pounds (lb) and mass is measured in Slugs (?). Weight and mass are related by the equation W=mg, where W is the weight, m is the mass, and g is the acceleration due to gravity (g=9.8m/s2=32ft/s2 on the surface of the earth). Of course, mass can also be measured in grams, but one should not use grams in the weight formula if you want the weight to be in Newtons.]

Streak is the color of a mineral in a finely powdered form. This is usually determined by running the mineral across a piece of unglazed porcelain called a streak plate (or just unglazed white tile found at the hardware store). Streak properties of minerals.

Luster is the appearance or "quality" of light reflected from a minerals surface. It is often divided into metallic and non-metallic luster.

Color is a property that describes itself. It is the color of a mineral. Most geologist consider this property a weak differentiator among minerals. But a few minerals will possess a very "striking" color.

Other Properties: Magnetic (technically speaking it is usually ferromagnetism) - is it attracted to a permanent magnet? Fluorescence - becomes luminescent during exposure to UV or IR light. Phosphorescence - stays luminescent even after exposure to UV or IR light. Pyroelectricity - temperature changes will cause charges to build up on the surface. Piezoelectricity - pressure changes will cause charges to build up on the surface. Solubility - does it effervesce in dilute HCl acid? (Carbonate minerals usually do effervesce.) Fusibility - can an intense heat (flame) cause two samples to fuse together? Fracture - minerals can break in distinctive ways that are different than cleavage. Tenacity - resistance to breaking when exposed to mechanical stress.

In essence, any physical property that differs between minerals can be used to help identify minerals!

Mineral Groupings (or "Families") (Web links provided by the theimage and Amethyst Galleries, Inc., )

(Click on the minerals)

Some interesting minerals The clay mineral Montmorillonite (commonly referred to as the expansive or swelling clay) can expand up to 15 times its original volume depending on the subsurface moisture content. It can also produce up to 500 kN/m2 of pressure when expanding. A large number of you probably have Quartz wrist watches. Quartz has the property of being piezoelectric. It vibrates with a very regular pattern when placed into an oscillating electric circuit. The vibrations occur at a rate of 100,000 vibrations per second. Some quartz clocks are accurate to within 1 second every 10 years.

Keeping the carrots straight: A carrot is a vegetable. The term karat refers to the purity of gold. A 24

karat necklace is pure gold but a 14 karat necklace is an alloy with copper or silver mixed with it. And a carat is a measure of the mass of a precious gem (1 carat = 0.2 grams).

Minerals - Related Web Links GOOGLE search for Minerals The Athena Mineralogy gargantuan mineral database A list of mineral properties from Amethyst Galleries, Inc. A very large mineralogy database, contains physical and optical properties, pictures, several classification systems The roving "geologist" on Mars (a.k.a. the Mars Pathfinder mission) Description of mineral properties from UTEP Description of ions and minerals and mineral properties from University of Saskatchewan Google - Search for Mineral Properties

On-line Lecture Notes GOOGLE search for mineral lecture notes Minerals by Steve Dutch, Natural and Applied Sciences, UW-Green Bay Dr. Andy Frank's Physical Geology Minerals Dr. Pamela Gore's Mineral lecture notes Atoms, Elements, and Minerals - Dr. Steven D. Schafersman, Miami University Dr. Susan DeBari's lecture notes on Minerals and Rocks Google - Search for Lectures on Minerals

Raw materials Raw Materials - Lecture Notes

Having a sufficient supply of raw materials is vital to the economy of a nation. These raw materials must be "mined" from the earth or recycled (if possible).

Energy Resources Renewable resources can be replenished over a short time span (about 100 years maximum). Examples include: hydroelectric, wind, tides, geothermal, solar, biomass

Non-renewable resources cannot be replenished over a short time span (usually needs millions of years to replenish). Once consumed it is gone forever! Examples include: fossil fuels (Oil, coal, natural gas, etc.), uranium

Energy costs are a big factor when estimating construction jobs. The energy to process the materials (iron, wood, steel, etc.), the energy to transport the goods to the site, the energy to run the equipment (compactors, welders, vehicles, backhoes, etc.). Heating energy is sometimes needed for sites during the

winter.

Energy sources (percent of the total energy consumed that comes from that source): 40% petroleum, 23% natural gas, 22% coal, 8% nuclear, 5% hydroelectric, 2% others.

The big picture (Source: A. Hobson, Physics: Concepts and Connections, Prentice Hall 1995)

Percentage of the total U.S. resource consumed by 1992

Years remaining until total resource is gone at present annual

rate

Coal 2 3600

Oil 70 25

Natural Gas 40 69

Uranium (without breeder reactors)

8 200

Is There a Looming Oil Crunch?

As reflected in the table above, the world supply of oil appears heading for a disaster. To truly understand the situation one needs to know (1) how much oil has been extracted to date, (2) an estimate of known reserves and the amount that can be pumped from them before they dry up, and (3) an educated guess at the quantity of oil that remains yet to be discovered and exploited. The first is easy to determine the last two are quite difficult for a variety of reasons - one of them being that companies have an incentive to make unrealistically large projections of known reserves. The latest information about this situation comes from a Scientific American article in March 1998 with a special report titled Preventing the Next Oil Crunch:

"...(authors) conclude that before the next decade is over the flood of conventional oil will crest, and production will enter a permanent decline. These analysts marshal an impressive body of statistics to support their projections. If they are right, the world will need to move quickly to avoid the price hikes, recessions and political struggles that oil shortages - or the threats of them - have historically provoked." Web page and group devoted to the study of when oil production will peak.

Mineral deposits are usually divided into metallic and nonmetallic. Metallic - Fe, Al, Chromium, Tin, Uranium, Silver, Mercury, Gold Nonmetallic - Salt, Building Stones (or Dimension Stones), Sand and Gravel, Phosphorus, Sulfur

If a mineral deposit is economically worthwhile to mine, then it is called an ore. A high grade ore consists of a high concentration of a valuable mineral in a localized volume of earth.

Ways to extract the materials from the ground

Open-pit or "Strip" mining is carried out at the surface and digs down removing the overlaying material. Underground mining involves tunneling into the earth and removing material. Usually consists of mine shafts down to a horizontal layer of ore being removed. Placer mining usually involves the separation of valuable metals or nonmetals from unconsolidated material near the surface. Bauxite, the principle ore of aluminum, is often extracted this way.

Video of Soudan Underground Mine (~90 Mb, will require fast internet connection)

If you are hunting for a particular mineral for mining, it is important to know how the deposits are usually formed (this link talks about mineral exploration and production). Igneous activity can produce high grade ores from fractionalization or magmatic segregation of magma chambers. Iron oxides have been found to solidify and settle towards the bottom of the chamber during cooling. Hydrothermal activity may carry metallic ions into surrounding rocks. Many gold and silver deposits have precipitated from hydrothermal solutions. Some iron rich rock layers have resulted from sedimentation of pre-cambrian seas. An example is the taconite mines in the Lake Superior region.

Annual Nonmetallic Consumption by the U.S. (1996)

Annual Metallic consumption by the U.S. (1996): Iron and Steel - 1.5x1011 kg Aluminum - 6.6x109 kg Copper - 2.7x109 kg Lead - 1.6x109 kg Zinc - 1.3x109 kg

Strategic Mineral is one that is in short supply within a nations boundaries but is vital for the nations economy. These minerals are usually stockpiled during peace time or mined from "conquested" lands. Tin, chromium, manganese, and tungsten are considered strategic minerals in the U.S. (Some would argue that wars have been fought over "strategic minerals", e.g. Persian Gulf war, if one considers oil to be such a mineral.)

(An article in the November '96 issue of Physics Today has a fascinating article on the Soviet Unions efforts to join the nuclear club immediately after WWII. The article was titled Trinity at Dubna.) Paragraphs from this article:

"Materials for the witches cauldron....During World War II, uranium was in short supply. There was no market for it. In the Soviet Union in 1945 there were about five tonnes of uranium on hand and few known deposits or ore. This lack of material formed the basis of the American belief that a Soviet A-bomb was decades away. Speakers at the Dubna conference revealed that a stash of 45 tonnes of uranium was located in eastern Germany at the end of the war. Directed by good intelligence, that material was soon liberated. Its

delivery to Laboratory No. 2 allowed the Soviets to start work there on the F-1 reactor at once, saving perhaps a year's time. Simultaneously, a crash effort started to mine known Soviet uranium reserves, in some cases with horses. Soon, 63,000 people were involved. Major national radiological surveys began, with over 250 teams combing the entire USSR. Every geologic survey, no matter what its original purpose, was to look for signs of radioactivity. As a result the Soviet government found 50 uranium deposits with reserves of 84,000 tonnes. In the decade of 1945-55, the Soviet uranium inventory grew from 5 tonnes to 6,800 tonnes."

Minerals Used in Construction

Raw Materials - Related Web Links

Frequently Asked Questions on Nuclear Power Wisconsin Electronic Reader (Image Gallery of Mining in Wisconsin) Resources from the Dept. of Geology and Geophysics, UW-Madison (by Philip E. Brown) Construction and Manufacturing Mineral Law and Land Access Energy Resources Iron, Steel, Ferroalloy Metals Nonferrous Metals Case Study on Copper in the Lake Superior region Chemical and Industrial Metals Fertilizer and Chemicals Environmental Geochemistry and Mining Google - Search for Mineral Resources Related businesses to Ceramics and Industrial Minerals DECO Marble and Granite. LTD A long list of U. S. Departments of Energy Efficiency and Renewable Energy Network.

On-line lecture notes

Mineral Resources - Dr. Steven D. Schafersman ,Miami University

Review Quizzes Section 2

Review Quiz Section 2 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapter Minerals) Minerals - Dr. Andy Frank's Review Exam Minerals - North Dakota State University Self-Test, Geology 120

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 3 Plate Tectonics Jump to: Lecture Notes, Web Links

Earthquakes Jump to: Lecture Notes, Web Links

Volcanoes Jump to: Lecture Notes, Web Links

Review Quizzes

Plate Tectonics Plate Tectonics - Lecture Notes

Gross Features of the Earth (REarth=6370 km)

(Moving from a high altitude above the surface to the center of the earth.) Ionosphere - ~100 km (Layers of the atmosphere are usually separated by changes in temperature.) Mesosphere - ~50 km (Ozone layer exists between the mesosphere and stratosphere) Stratosphere - ~12 km Troposphere - clouds and water vapor

Crust - Is the outer layer of the earth with an average thickness of about 15 km. It has an average density of 3,000 kg/m3. (The density of iron is 7,900 kg/m3 and marble is 2,700 kg/m3.) Mantle - Is the largest part of the earth by volume (80%), extends between 15 km to 3,000 km in depth (going towards the center), and has an average density of 5,000 kg/m3. Core - This part of the earth is usually divided into an inner core and an outer core. Both parts have an abundance of nickel and iron. The average density is 11,000 kg/m3. The outer core is liquid (molten rock) but the inner core is considered a solid metallic material. How do we know of this internal structure?

Most of what we know comes from examining the propagation of seismic waves (ground vibrations) and modeling the structure of the earth so that it is consistent with the seismic studies (and other experimental observations).

It is sometimes instructive to examine the earth's crust and mantle in a slightly different way. It can be broken into a top, solid (or rigid) layer called the Lithosphere. At a depth of about 100 km, the mantle becomes capable of flowing. From this depth to about 500 km is called the Asthenosphere. Note: The Lithosphere includes the crust and the very top part of the mantle. The Asthenosphere is part of the mantle.

Plate Tectonics

During about 1912 Alfred Wegener, a Meteorologist, proposed a theory of Continental Drift. He suggested that the earth's crust was composed of solid "plates" that were in motion (albeit slow, ~ 6cm/yr) and about 200 million years ago all the continents were connected into a super-continent called Pangea. This hypothesis was not well received when it was first proposed.

"Wegener's hypothesis in general is of the foot-loose type, in that it takes considerable liberty with our globe, and is less bound by restrictions or tied down by awkward, ugly facts than most of its rival theories. Its appeal seems to lie in the fact that it plays a game in which there are few restrictive rules and no sharply drawn code of conduct." (R.T. Chamberlain - A Geological Miscellany, Princeton Press, 1982)

This theory is true (such that, it fits almost all observations and most scientist agree with it). Plate Tectonics integrates continental drift, sea floor spreading, and seismic zones.

(Click on the map item)

Plate Tectonics - Related Web Links

Plate Tectonic Animations from UC-Berkeley On-line Book This Dynamic Earth: The Story of Plate Tectonics by W. Jacquelyne Kious and Robert I.

Tilling USGS historical perspective on Tectonic Plates Paleomagnetism and the reversal of earth's magnetic field Google - Search for Plate Tectonics On-line Lecture Notes

GOOGLE search for plate tectonic lecture notes Dr. Andy Frank's Physical Geology Plate Tectonics Dr. Pamela Gore's Earth's interior lecture notes Dr. Susan DeBari's Plate Tectonics lecture notes

Earthquakes Earthquakes - Lecture Notes

"Civilization exists by geologic consent....subject to change without notice." - Will Durand, Historian

The earth is dynamic. It has internal processes that are in motion. Huge forces produced by the internal processes of the earth are constantly pushing and pulling at the earth's Crust. These forces produce stress within the solid rock layers. When sufficient stress is built-up a threshold is reached and the rock layers will "snap".

Earthquakes are vibrations of the earth caused by a rapid release of energy. This energy comes from the stress built up along fault lines (or underground nuclear explosions). The so-called "Elastic/Rebound" theory. Seismology deals with the measurement of these ground vibrations.

Seismographs consist of inertia member, transducer, and a recorder. Here is an example of the readout from 3 small earthquakes. (Real time seismogram readouts from UC-Berkeley) Body Waves: P-Waves (or primary waves) travel quite fast (~7 km/sec), shakes the ground in a compression/expansion mode, and can travel through the outer core of the earth. S-Waves (or secondary waves) travel a bit slower (~4 km/sec), shakes the ground in a transverse mode, and cannot travel through the outer core. Surface Waves shakes the ground in a transverse mode and travels much slower than S-Waves.

The Richter Magnitude Scale is based upon the formula M=log(A)+C. M is the magnitude, A is the amplitude of ground shaking, and C is the distance away from the focus. This implies that a magnitude 4 quake has 10 times the amplitude of a magnitude 3 quake measured from the same location (More Detail from USGS). A rather subjective scale also exists called the Modified Mercalli Intensity Scale.

Animation of Earthquake Wave Propagation and Epicenter Determination

UW-Stout's

S102 Seismometer

Dr. Scott's

PowerPoint Presentation on the S102 Seismometer and Earthquakes

The best scientist can do in predicting earthquakes is to assign probabilities. An earthquake can be more or less likely to occur in a certain region during a specified time. Compression and tension builds up within rock structures in a cyclical fashion.

The date corresponding to position (a) in the graph has a much lower probability of an earthquake happening than position (b).

Armenian earthquake of 1988 was a M=6.9 and 25,000 people died. Loma Prieta (Oakland, CA) earthquake of 1991 was a M=7.1 and 100 people died. What is happening here?

Effects of Earthquake Ground-Shaking on Structures

Effects of Earthquakes 1. Fire - gas lines break and create fires, water lines have also been ruptured (so much for fighting the fire) 2. Damage to Structures 3. Seismic Sea waves (Tsunami) 4. Landslides 5. Land Movement (surface shifting, sometimes produce visible cracks in the ground) 6. Liquefaction - Shaken soil or sediments will become like "quick sand" and loose their ability to support structures. This behavior can be demonstrated by placing a weight onto a pan full of loose sand and shaking the pan. The weight will sink and tilt. (More on liquefaction during the Kolbe, Japan, earthquake.) 7. Sound?

Tsunami evacuation route sign in

Long Beach, WA.

Earthquakes - Related Web Links

USGS Response to an Urban Earthquake - Northridge '94, The Causes and Effects of Liquefaction, Settlements, and Soil Failures Virtual Earthquake, a nice interactive site that provides a good tutorial SeismoCam, Cooperative project between Caltech and USGS (Real-Time view of a seismograph) JAVA Simulations of a model Seismograph FEMA Earthquake Fact Sheet (Adobe Acrobat format) National Earthquake Information Service Near-Real-Time Global Earthquake Events National Earthquake Hazard Reduction Program (FEMA, NSF, USGS, NIST) Reducing Earthquake Losses Fact Sheet from the USGS Northern California Earthquake Data Center Advanced Research on Earthquakes from Harvard USGS On-line Earthquake Resources On-line Book on Earthquakes by Kaye M. Shedlock & Louis C. Pakiser (USGS) Surfing the Internet for Earthquake Data (collection of web links) Google - Search for Earthquakes On-line Lecture Notes

Dr. Andy Frank's Physical Geology Earthquakes Dr. Pamela Gore's Earthquake lecture notes

Dr. Susan DeBari's Earthquake lecture notes Seismology and The Earth's Interior - Susan Schwartz, UC-Santa Cruz Google - Search for Earthquake Lectures

Geophysical Exploration: Geophysical Exploration (surveys include: gravity, magnetic, refraction seismicity, DC resistivity). Steven Roecker's Applied Geophysics class (lecture notes and links, includes gravity, seismic, electric, and magnetic measuring techniques). Dick Gibson's primer on using gravity and magnetism to explore subsurface geology. Google - Search for Geophysical Exploration

Volcanoes Volcanoes - Lecture Notes

Unlike earthquakes, volcanic eruptions can be predicted.

Evidence that a volcanic eruption is imminent: Dramatic increase in earthquake activity in the area

Tilt meters (usually laser surveying) indicate the mountain is bulging Volcanic gases emitted from fissures in the ground

Three general ways to characterize volcanoes: Extinct - no signs of volcanic activity, lots of erosion has occurred since the last eruption. Dormant - not much erosion, "sleeping" and is capable of erupting, little to no signs of volcanic activity. Active - Some historical record of an eruption or is currently erupting.

Types of volcanoes

Shield volcanoes are relatively quiet, gently sloping, low viscosity magma (usually low in SiO2), largest

in overall size, spews the least amount of gases Example: Kilauea

Composite (or Stratovolcano) are explosive, steeply sloped, high viscosity magma, intermediate in size, intermediate gas content Example: Mt. St. Helens, Pinatubo, Mt. Shasta

Cinder Cone volcanoes are somewhat explosive (not as much as Composite), have the steepest sloping, high viscosity magma, smallest in overall size, highest volcanic gases (another Cinder Cone picture) Example: Paricutin

Volcano Relative Sizes

Click on picture to enlarge. This is a composite of three pictures.

Aspects of volcanic eruptions Pyroclastic Debris is the material ejected from an erupting volcano. Usually classified as (small to large) ash, cinders, blocks, and bombs. Pyroclastic Flow (or fiery cloud) is a cloud of super-heated gas and ash that flows down slope from an erupting volcano. It can reach speeds of 100 mi/hr and has a temperature of ~800oC (hot enough to melt glass). It burns anything combustible. Volcanic Gases include CO2, CO, HCl, HF, H2S, SO2, H2, and H2O (many of these are toxic in

sufficient concentrations)

Craters of the Moon Slide Show (PowerPoint

format)

Pictures taken during a trip to the Craters of the Moon National Monument in Idaho in August, 2002.

Volcanoes of the Cascade Mountain Range

(PowerPoint format)

Pictures taken in 2003 (Mt. Rainier and Mt. St. Helens) and 1992 (Crater Lake). Select speaker

notes in the slide show if you want more informatiion.

Some Interesting Volcanoes Vesuvius erupted in 79AD and buried the cities of Herculaneum and Pompeii (it was 10 times the power of Mt. St. Helens). Krakatoa is the considered the world's greatest explosive eruption. Before the eruption is was an island

that stood 800 m above sea level. After the eruption it became submerged 300 m below sea level. Mt. St. Helens erupted in 1980. One of the best documented eruptions in history. Pinatubo erupted in 1991. One of the most recent eruptions was Montserrat in the West Indies

Volcanoes - Related Web Links

On-line Books from the USGS (contains: VOLCANIC AND SEISMIC HAZARDS ON THE ISLAND OF HAWAII, VOLCANIC HAZARDS AT MOUNT SHASTA, CALIFORNIA, VOLCANOES, VOLCANOES OF THE UNITED STATES, MONITORING ACTIVE VOLCANOES, ERUPTION OF HAWAIIAN VOLCANOES -- PAST, PRESENT AND FUTURE, ERUPTIONS OF MOUNT ST. HELENS -- PAST, PRESENT, AND FUTURE) Deadliest Eruptions Volcano World Smithsonian Institute's Global Volcanism Program Virtual Field trip to the Hawaiian volcanoes Take a virtual hike up Mt. St. Helens (this link provides lots of information on Mt. St. Helens) Volcanoes on other worlds On-line video clips of volcanoes Google - Search for Volcanoes On-line Lecture Notes

GOOGLE search for volcano lecture notes Dr. Andy Frank's Physical Geology Volcanoes Dr. Pamela Gore's lecture notes on Volcanoes Dr. Susan DeBari's lecture notes on Volcanoes Google - Search for Volcanoes, Lectures

Review Quizzes Section 3

Review Quiz Section 3 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapters Earthquakes and Earth's Interior, Minerals, Volcanoes and Igneous Activity, Plate Tectonics) Volcanoes - Dr. Andy Frank's Practice Exam Earthquakes - Dr. Andy Frank's Practice Exam Plate Tectonics - Dr. Andy Frank's Practice Exam Earthquakes and Seismicity - North Dakota State University Self-Test, Geology 120 Plate Tectonics - North Dakota State University Self-Test, Geology 120 Deformation and Structure - North Dakota State University Self-Test, Geology 120 Internal Structure of the Earth - North Dakota State University Self-Test, Geology 120

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 4 Igneous rocks Jump to: Lecture Notes, Web Links Sedimentary Rocks Jump to: Lecture Notes, Web Links Metamorphic rocks Jump to: Lecture Notes, Web Links

Review Quizzes

Igneous rocks Igneous Rocks - Lecture Notes

As one descends deeper into the earth's surface, the temperature rises. This temperature rise is called the geothermal gradient and has an average value of 30oC. Scientist believe this heat source originates from radioactivity or the initial coalescence of the earth from a gaseous cloud. The Jovian planets have a heat imbalance mystery. Such that, they emit more radiant energy than they absorb from the Sun. Note: Many rocks melt at 1500oC (or 2,757oF) and room temperature is about 23oC.

Terminology Molten rock in the ground is called Magma, extruded onto the surface it is called Lava. If it is blown out of a volcano, it is called pyroclastic debris. All igneous rocks have been formed from the solidification of molten rock.

As a general rule, both the melting (solid to liquid) and crystallization (liquid to solid) for rocks into magma and magma into rocks are complex.

Bowen's Reaction Series provides us with a glimpse of how molten rock solidifies:

"Differences in end products depend on the rate at which the magma cools and on whether early formed minerals remain in or settle out of the remaining liquid during its crystallization."

There exists a discontinuous reaction series where forming minerals will change their crystalline structure and a continuous reaction series where forming minerals keep the same crystalline structure.

Keep in mind: First to crystallize (or solidify) have a high temperature melting point. Last to crystallize have a low temperature melting point.

A simplified view

Some types of igneous rocks (and magma) "prefer" one tectonic setting as opposed to another. Basaltic (or mafic) magma has a high iron and magnesium content. This magma is usually associated with Shield volcanoes and has a dark color. Andesitic magma has a mixture of iron, magnesium, sodium, and silica (SiO4). It is intermediate between Basaltic and Granitic magma. Granitic (or sialic) magma has a high concentration of Silicon and Aluminum. It is usually associated with composite volcanoes and has a light color. (Page 63 in Tarbuck and Lutgens has a good graph.)

The texture of igneous rocks are often used in identification. The texture is determined by the size, shape, and arrangement of the interlocking mineral grains. The most important factor influencing the texture of igneous rocks is the rate of cooling for the magma.

Igneous Rock Textures Phaneritic (or granular) texture has large mineral grains from slow cooling (usually below the earth's surface). The grains can clearly be seen with the un-aided eye. Aphanitic texture occurs from rapid cooling and consists of individual minerals so small that they cannot be identified without a microscope. Glassy texture consists of ions disorganized as in a liquid but frozen in place by an extremely rapid cooling. Vesicular (can be aphanitic and vesicular) rocks are very porous because of gas bubbles in the magma or lava when it cooled. Porphyritic is a mixture of large mineral grains in an aphanitic or glassy goundmass (smaller crystal material). Pegmatitic textured rocks have exceptionally large granular mass of crystals formed by hydrothermal solutions late in the cooling process.

Igneous Rock Formations [Terminology: a pluton is igneous rock formation that has solidified underground, tabular means that it is flat (i.e. width is significantly less than the length), discordant implies that the igneous rock formation cuts perpendicular to existing rock layers, and concordant igneous rock cuts parallel to existing rock layers.] Sill are concordant tabular plutons. Dikes are discordant tabular plutons. Lopoliths are concordant tabular plutons shaped like a spoon (sags downward). Laccoliths are massive concordant plutons with domed tops. Batholiths are massive plutons (10-15 km thick) having no particular shape. (El Capitan and Half Dome in Yosemite National Park are part of the Sierra Nevada Batholith.)

Sylvan Lake in Custer State Park, South Dakota. These formations are mostly granite. (For more information on the geology of this area see the Geology of South Dakota fact sheet.)

Igneous Rocks - Related Web Links Dr. Andy Frank's Physical Geology Igneous Rocks Igneous Rock lecture and Ancient Lava Flows / Plutons from Dr. Pamela Gore Geology 41 at Duke University - Igneous Activity and Metamorphic Rocks (Part I and Part II) Dr. Susan DeBari's lecture notes on Igneous Rocks Google - Search for Igneous Rocks

Sedimentary Rocks Sedimentary Rocks - Lecture Notes

About 95% of the outer 10 km is made up of crystalline rock (igneous and metamorphic), 5% is sedimentary. However, sedimentary rocks make up about 75% of the rocks exposed at the surface. Note: Most rocks that can be seen on the Red Cedar trail in Menomonie, WI, are sedimentary of pre-cambrian time.

Sedimentary Rocks are divided into two categories: Detrital (terigenous or clastic) sedimentary rocks are derived from the weathering of pre-existing rocks which have been transported to a depositional basin. Non-detrital (or chemical) are produced by chemical or biological processes.

Method of sediment transportation (annual delivery to oceans):

Rivers - 10 billion tons Glaciers - 100 million-1 billion Wind - 100 million Extraterrestrial - 0.03-.3 tons (meteors, etc.)

Material can be deposited when its agent of transportation no longer has sufficient energy to keep it moving. Material can also be precipitated out of a solution. Dissolved material is converted to a solid.

Detrital Sedimentary Rocks have a clastic (or broken, fragmental) texture consisting of 1. Clasts - large pieces such as sand or gravel 2. Matrix - mud or fine grain sediments (this surrounds the clasts) 3. Cement - calcite, iron oxide, silica

The most common detrital rocks (in order of decreasing size of clasts) are Conglomerate or Breccia, Sandstone, and Mudstone or Shale. The clasts within a breccia are sharp as compared to the conglomerate clasts which are rounded. This suggests a difference in weathering and/or transporting.

Wentworth Scale of Particle Sizes

Boulder >256 mm

Cobble |

Pebble, Gravel |

Granule (decreasing in size)

Sand |

Silt |

Clay <0.004 mm

Chemical/Biochemical Sedimentary Rocks

Evaporates form from the evaporation of water. Examples: rock salt of Halite, Rock Gypsum, Travertine (caves and hot springs) Carbonates mainly composed of limestones and dolostones. (reacts with HCl) Siliceous rocks are those which are dominated by Silica (SO2). They commonly form from silica

secreting organisms such as diatoms, radiolarians, or some type of sponges. Examples: Diatomite, Chert

The process that converts unconsolidated rock-forming materials to consolidated is lithification. Diagenesis is the term describing physical, chemical, or biological changes in the rock before any significant amount of heat or pressure is applied.

Features of sedimentary rocks Bedding planes - usually horizontal, they represent changes in the depositional environment.

Sedimentary Facies - the characteristics of a unit of sediments which can be used to interpret the depositional environment. Ripple Marks, Mud Cracks

"Organic" Sedimentary Rocks: Peat, Lignite, Bituminous (coal, low carbon, sooty), Anthracite (coal, high carbon, not sooty, metamorphic rock?)

Sedimentary Rocks - Related Web Links

Dr. Andy Frank's Physical Geology Sedimentary Rocks Dr. Pamela Gore's lecture notes on sedimentary rocks Dr. Susan DeBari's lecture notes on sedimentary rocks I and II Geology 41 at Duke University - Sedimentary Rocks With Examples of Textures and Sedimentary Structures Google - Search for Sedimentary Rocks

Metamorphic rocks Metamorphic Rocks - Lecture Notes

Metamorphism is defined as a set of processes involving

heat, pressure,

and chemical fluids

in which rocks undergo a change in mineralogy, texture, or both. A contact metamorphism occurs when rocks get close to molten rock (but does not undergo melting). This metamorphism can be found surrounding most igneous rock formations. When a large region of rocks get exposed to high heat and pressure, it is a regional metamorphism. This happens when rocks are buried to a great depth.

Some regional metamorphism is associated with colliding plate boundaries.

Metamorphic Textures can be either foliated or non-foliated. Foliated metamorphic rocks contain mineral grains that have been flattened. The grains form an elongated, rod-like appearance. There are several types of foliation: schistosity, slaty cleavage, gneissic banding. Examples: Slate, Phyllite, Schist, Gneiss (click on graph below for pictures) Non-foliated metamorphic rocks contain mineral grains that are equidimensional. Examples: Marble, Quartzite

A low grade metamorphic rock is generated in a relatively low temperature and pressure conditions. A

high grade metamorphic rock is generated in high temperatures and pressures. The grade of metamorphism is similar to the metamorphic facies. [Note: Generically, a facies is an assemblage of mineral or rock features reflecting the environment in which the rock was formed.] (see pg. 166 in Tarbuck and Lutgens)

Example Progression from Low to High Grade Metamorphism

(Click on a metamorphic rock.)

Geology Satire, A story read by Dr. Scott (audio, 3.7 Mb)

Metamorphic Rocks - Related Web Links

Dr. Andy Frank's Physical Geology Metamorphic Rocks Dr. Pamela Gore's lecture notes on metamorphic rocks Dr. Susan DeBari's lecture notes on metamorphic rocks Geology 41 at Duke University - Igneous Activity and Metamorphic Rocks (Part I and Part II) Google - Search for Metamorphic Rocks

Review Quizzes Section 4

Review Quiz Section 4 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapter Igneous Rocks, Metamorphic Rocks, or Sedimentary Rocks) Igneous Rocks - Dr. Andy Frank's Practice Exam Sedimentary Rocks - Dr. Andy Frank's Practice Exam Metamorphic Rocks - Dr. Andy Frank's Practice Exam Igneous Rocks and Processes - North Dakota State University Self-Test, Geology 120 Metamorphic Rocks - North Dakota State University Self-Test, Geology 120 Sedimentary Rocks - North Dakota State University Self-Test, Geology 120

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 5 hydrology Jump to: Lecture Notes (STREAM Dynamics, Groundwater, Permafrost), Web Links

mass movement Jump to: Lecture Notes, Web Links

weathering Jump to: Lecture Notes, Web Links

Review Quizzes

hydrology Hydrology - Lecture Notes

"All the rivers run into the sea, yet the sea is not full; unto the place from whence the rivers come, thither they return again." Ecclesiastes, Ch. 1

The movement of water is called hydrology. Water doesn't just appear. It moves around in a "cycle". In this cycle it can take the form of solid (ice), liquid, gas (water vapor).

Historically, people weren't sure where the water originated. They did not know what kept supplying rivers and springs with water even during dry spells. Many postulated the existence of complex underground channels that enable ocean water to flow inland to springs. This is not found to be the case. Pierre Perrault (1674) was the first to measure precipitation and drainage from the Seine River basin. Edme' Mariotte (1684) demonstrated that much of the rainfall infiltrates into the ground. Edmund Halley (1693) investigated evaporation of the Mediterranean Sea. He found that more than enough water was being evaporated to feed the rivers flowing into this Sea.

Terminology Water falling to the ground from the atmosphere is precipitation. (9x1013 m3/yr falls onto land, 37x1013 m3/yr falls into the ocean) A large amount of H2O is taken back into the atmosphere by evaporation and plant transpiration. These two

processes are usually grouped together as evapo-transpiration. (40x1013 m3/yr from the ocean, 6x1013 m3/yr from the soil and surface water) For the precipitation that falls onto the ground, some goes into runoff (rivers and surface water), another soaks into the ground by a process of infiltration. Water that sinks into the ground is called groundwater. The drainage basin of a river is the entire area from which a stream and its tributaries receive their water.

The water cycle can be summed up schematically by

Where is all the water on the earth? 97.2% oceans, 2.15% ice caps and glaciers, 0.65% lakes, streams, groundwater, and atmosphere Where is all the freshwater on the earth? 85% ice caps and glaciers, 14% groundwater, 0.5% lakes and reserviors, 0.3% soil moisture, 0.05% water vapor, 0.004% rivers

Stream Dynamics

The flow of water in a stream is usually characterized as being laminar (usually low velocity, mature streams) and turbulent (usually high velocity, young streams). Discharge is an important quantity when describing a stream's flow.

Discharge has units of volume per unit of time (such as m3/min, ft3/min, etc.). It is a measure of the volume of water that passes a particular point along a river (or cross-sectional area) in a given amount of time.

(Discharge) = (cross-sectional area) x (average velocity)

The measure of discharge as a function of time is called a hydrograph (shown below).

Standard hydrograph. Web page describing the Red Cedar River hydrograph and pictures.

It is quite important to ascertain the threat of flooding in a proposed construction area. How can this be done?

I. Examine the general topology. Does it look like a potential floodplain of a river? II. Talk to the "indigenous" people. Ask them if a particular area floods and how often. III. Examine historical records of flood levels and the number of occurrences. IV. Sometimes flood waters will leave marks on buildings and trees. This will indicate some of the highest flood levels. V. The soil may contain evidence of sedimentation from a floodplain.

Potential for flooding is a probability. Let P equal the probability in any given year that a flood of a given stage will occur. Then

.

This is a close approximation to a true statistical analysis. It should be noted that artificial structures built in or around

rivers may change the probabilities over time.

Animation of flooding and hydrographs This animation is not a theoretical model. It is just an illustration of the basic principles in stream dynamics. (Such that,

some details are not to scale)

Basic Principles (Assuming the same precipitation onto the rivers drainage basin): 1. Urbanization (pavement, residential housing, etc.) of a rivers drainage basin will cause the peak discharge to increase and the time lag to decrease. Less infiltration and more runoff that moves into the river more quickly. 2. Dam construction allows the downstream discharge to be regulated. This usually reduces the peak discharge and increases the time lag. 3. Constricting a rivers floodplain with flood walls, dikes, and/or levees causes the peak discharge to increase and time lag to decrease in spots downstream. When a river is allowed to spread out into the surrounding floodplains, the water slows down and it "stretches" out with respect to a downstream hydrograph.

As a general rule, artificial structures placed into a river or a river's floodplain will usually change the dynamics of that river with regards to flooding.

The "ultimate floodplain management?":

"After ordering tens of thousands of residents to abandon their homes, engineers dynamited levees along a stretch of the swollen Yangtze (river in China) on Sunday to ease floodwaters menacing cities in central China...engineers blew up secondary dikes in Jianli County, about 90 miles upriver from Wuhan, a tri-city industrial area with a population of 7 million...Engineers hope the diversion of up to 28 billion cubic feet of water into miles of farmland behind the dike will lower the raging Yangtze's water level by as much as 10 inches." (Pioneer Press article, St. Paul, MN, China Dynamites Levees to Spare Cities, 8/8/98)

Flooding and Construction Fact Sheet

Erosion and Deposition

Most stream erosion occurs by lifting loose unconsolidated particles and by abrasion. In general, the stronger the water current - the more the erosion.

Sediments in the stream travel as a bed load, suspended load, or dissolved load. When a river overflows its banks, it will drop much of its load because of the water slowing down. This is why you'll find a lot of silt and sand within floodplains.

Beaver Creek in the Beaver Creek Reserve near Eau Claire, WI.

This stream meanders and erodes the banks on the outside of the river bends where the water is moving fast. On the inside turns the water is moving more slowly creating deposition sand bars. This pictures shows a tree fallen across the river from the bank being eroded.

(Click on the picture to enlarge.)

River deposition pattern where Gilbert Creek empties into the Red Cedar just South of Riverside Park in Menomonie, WI.

(Click on the picture to enlarge.)

Gilbert Creek, a small tributary of the Red Cedar river just South of Riverside Park.

Riverside park looking South along the Red Cedar river. The picture was taken August 24, 2003, during a period of low discharge. The ripples in the surface of the water show the subsurface area where deposition is happening and a sandbar exists. The girl in the background is standing at the edge of the sandbar.

A closer look at the edge of the sandbar. The water gets deep very quickly on the left side of the picture

Another view of the sandbar. To the right is upstream in the Red Cedar river. To the left is where the sediment laden Gilbert Creek empties into the Red Cedar. The water slows down and deposits it's suspended load.

Water drainage flows downhill and can be affected by local geology (more or less resistance rock layers). There are generally 4 types of drainage patterns Dendritic, Radial, Trellis, and Rectangular.

Characteristics of Young and Old River Valleys

Immature (young) River Valleys

Steep gradient Waterfalls

"V" shaped valley (steep sides) Turbulent flow No meandering small floodplain

Mature (old) River Valleys

Gentle gradient Very few waterfalls

Wide "U" shaped valley Laminar flow

Meanders large floodplain

Click on picture to enlarge it.

© 2002, Alan J. Scott Snake River valley in Hell's Canyon National Recreational

Area in Idaho. Snake River is a young river valley.

Click on picture to enlarge it.

© 2002, Alan J. Scott Mississippi River Valley

Barn Bluff, Redwing, Minnesota Mississippi is an old river valley.

Drainage Concerns For Residential Construction

"In the space of one hundred and seventy-six years the Mississippi has shortened itself two hundred and forty-two miles.

Therefore ... in the Old Silurian Period the Mississippi River was upward of one million three hundred thousand miles long ... seven hundred and forty-two years from now the Mississippi will be only a mile and three-quarters long. ... There is something fascinating about science. One gets such wholesome returns of conjecture out of such a trifling investment of fact." -- Mark Twain

Groundwater

Groundwater is 66 times the amount of water in streams and freshwater lakes. Precipitation that infiltrates into the ground is called groundwater.

The zone of aeration is the region of soil closest to the surface. It contains some moisture but is not 100% saturated with water. As one digs deeper, the zone of saturation is encountered. This zone is 100% saturated. The boundary between these zones is called the water table.

The water table does reflect variations in the ground surface (such that, has a topology), the irregularities in the water table are less pronounced.

The ability of water to flow (or be transmitted) underground is termed permeability. For something to be permeable it needs to have a material that is porous and has some interconnections between the openings. A permeable material that actually carries underground water is called an aquifer. Low permeable material (i.e. solid rock) is called aquicludes. When the water table intersects the surface, a spring, swamp, river, and/or lake may appear.

How fast water travels through an aquifer follows Darcy's Law:

.

The velocity of the water is proportional to k (which is related to the permeability) and is proportional to the hydraulic gradient, h/l (which is the slope of the water table). The volume of water flow per unit of time follows the equation Q=A . v where A is an area and is related to the geometry of a well.

What happens to the water table when a well is drilled and water is pumped? A cone of depression is formed in the water table.

Sometimes the use of underground water needs to be regulated. Suppose a farmer is irrigating their crops by pumping water from well A. If another farmer comes along with a bigger irrigation system requiring a deeper well and higher pump

rate at B, you can see what happens to well A. Underground pumping can also cause land subsidence.

More on Water Permeability and Dewatering

An artesian well requires a specific underground geologic structure to exist. It requires an inclined aquifer bounded on the top with an aquiclude. Wells drilled through the aquiclude into the aquifer may have water freely flowing out without any pumping necessary. (see fig. 11.14 in Tarbucks and Lutgens)

State Revokes Well-Driller's License, Dunn County News Article, December 5, 1999 After a Department of Natural Resources investigation, a well driller (from Eau Claire) had his license revoked for violating several Wisconsin well drilling codes. A State Administrative Law Judge found that the person had violated 23 separate codes on 340 occasions. "...license revoked for violations of Wisconsin well drilling codes that are designed to protect a pure water supply and assure private wells produce clean water....(the) violations included use of improper well construction methods, failure to report information about well construction and water testing, and construction of wells too close to possible pollutant sources." "...he did not collect many bacteriological water samples within 30 days of well completion...installed wells within restricted distances of solid waste or hazardous waste facilities without required variances...used unapproved drilling methods and unapproved well casing."

Karst Topograph are geographical regions that have been significantly shaped by water partially dissolving an underground rock strata (usually limestone). This topography has a large number of sinkholes on the surface.

Permafrost

If you are lucky enough (or un-lucky depending on the pay rate) to get a construction job in a cold region such as Alaska and a good portion of Canada, permafrost is going to be a big concern. Permafrost regions have soil that is frozen at some depth year round (see pg 210 in Tarbucks and Lutgens). This type of soil can be divided into two regions. An active region near the surface that experiences thawing/freezing and the permanently frozen ground underneath the active region.

THE PROBLEM - Thawed soil in the active zone is usually weak and compressible. Furthermore, it usually contains trapped water making it "muck-like". Two important rules need to be followed when building sturdy structures in regions of permafrost: 1. Base of the foundations should be placed into the permanently frozen ground. If the active region reaches below the base of the foundation, the foundation will lose its ability to support loads. 2. The foundation needs to be thermally insulated from the rest of the structure. One doesn't want heat from the building to melt the permanently frozen ground.

The Alaskan Highway project during WWII and the Alaskan Pipeline are two prime examples of building in permafrost regions. (A pictorial history of building the Alaskan Highway.)

Red Cedar River Aerial view with pictures of landforms and river dynamics.

Click on the picture for a larger version. (~6 Mb)

Here is a picture of myself (Dr. Scott) during a river dive down the Rainbow River in Florida.

Several years ago I had the opportunity to scuba dive in the Rainbow River in Florida. The water is a magnificently clear. The river begins at a large pond area which is being fed water through several springs in the bottom of the pond. These springs feed the stream with 500 million gallons of water per day. (I've also got a picture diving with Manitee's.)

Hydrology - Related Web Links

USGS Geology Water Cycle *New*

International Erosion Control Association, Photogallery pictures Water Quality Help Guide at Wilkes University - Excellent resource about "hard water", bacteria, contaminants, etc. Class tour of the Menomonie Hydroelectric Power Dam FEMA Fact Sheet on Floods and Flash Floods Resources from the Dept. of Geology and Geophysics, UW-Madison (by Philip E. Brown) Water and Soil Dr. Andy Frank's Physical Geology - Groundwater Dr. Pamela Gore's lecture notes on hydrology Dr. Susan DeBari's lecture notes on Rivers and Running Water Geology 41 at Duke University - Groundwater (Part I and Part II), Streams (Part I and Part II) Meteorology Education Links On-line Tutorial and Decision Aid Protecting Groundwater: A Guide for the Pesticide User Groundwater: Nature's Hidden Treasure USGS Real-time flow data for the Red Cedar River (station just downstream from the dam), USGS Water Resources and Publication Data for Wisconsin, USGS national water data St. Francis Dam Failure by Kelita Stephens Construction of the Hoover Dam Google - Search for Hydrology Google - Search for River Pictures Google - Search for River Dynamics Google - Search for Groundwater

mass movement Mass Movement - Lecture Notes

Earth material moving downhill in a solid or somewhat viscous form are called mass movements. This movement is analagous to a block on a inclined plane. When the downhill force of gravity exceeds the internal frictional forces resisting motion, the material will move. In other words, a slope will remain stable until the externally exerted stresses cause it to reach its threshold. This is the point to which the passive, internal frictional forces are exceeded.

These mass movements have been characterized as a slide, fall, flow, and heave (note: these are not mutually exclusive categories) Slide is when the material maintains continuous contact with the surface. It can preserve its form or be extensively deformed. Fall refers to the free fall of material (looses contact with the surface). Flow involves continuous movement with the material behaving in a plastic to liquid manner. Individual particles get rearranged. Heave is a slow movement where the particles are pushed up perpendicular to the sloping surface then "let down" in the direction of gravity.

Speed and Type of Movements

Slow Movements (1mm/yr - 1mm/day) Slow movement downward of surface material is called creep. Signs that creep is happening include posts tilting, soil profile, roots, trees tilting, etc. Frost heaving can occur when water gets behind or underneath an object and freezes. Upon freezing water expands and can apply large forces on objects. Solifluction refers to the downslope movement of debris under saturated conditions. This movement is common in regions of permafrost.

Moderate Movements (1 cm/day - 1 cm/sec) Slump is the downward and outward movement of earth traveling as a unit or as a series of units. Occurs many times after a hillsides slope has been changed. Commonly occurs when soil has been graded to steeply at a work site. Earthflows are slow but perceptible movements. These are usually helped by excessive moisture. If sufficient moisture is added it will become a mudflow. Debris slide involves the movement of comparatively dry unconsolidated material. It is usually coarser material than an earthflow.

Rapid Movements (can go quite fast - free fall) Rockfall is the free fall of earth material. It creates a build up of rocks at the base of cliffs called talus.

Factors that increase the chances of a slope failure: External Influences Removal of Lateral Support - too steeply grading hillside, erosion, etc. Removal of Underlying Support - dissolving rock layer beneath the surface, bearing capacity failure, mining Addition of Mass (assuming a cohesive soil) - adding weight to the hillside Addition of Lateral Pressure - expanding clay soils, water freezing Vibrations - earthquakes, blasting, heavy traffic, sonic booms, etc. Internal Influences Weathering - mechanical and chemical weathering can reduce the macroscopic bonding of particles within the soil. Pore Water - decreases the effective stress pushing the soil particles together. Organic Activity - removal of vegetative roots, burrowing animals, prying by plant roots

An Introduction To Slope Stability Theory

Slide show (with audio) of this slope failure in Menomonie, WI

Lake Bank Reconstruction Project - Summer 1999, Lake Menomin, Menomonie, WI (PowerPoint presentation) [Some text and audio still need added to this slide show, but I wanted to make it available to you for previewing.]

Mass Movement - Related Web Links

Images of how Mass Movements have affected buildings or structures Slump in a new road cut Broken Pavement Displaced Curb, Another Displace Curb

Dr. Andy Frank's Physical Geology Landslides FEMA Fact Sheet on Landslides and Mudflows (Adobe Acrobat format) Geology 41 at Duke University - Mass Movement (Part I and Part II) Landslide Mitigation Techniques by J. David Rogers (mitigation using subdrainage) Homeowner's Landslide Guide For Hillside Flooding, Debris Flows, Erosion, and Landslide Control published by the Oregon Emergency Management (FEMA) A huge landslide on Mars Mass Wasting - Prof. Stephen A. Nelson -Tulane University Mass Movement pictures from Washington State University Google - Search for Mass Movement Google - Search for Landslides

weathering Weathering - Lecture Notes

Geographical regions with high average rainfall and temperatures have the most weathering of natural materials. This usually implies that these regions also have the deepest soils (in particular, residual soils).

Weathering can be broken down into mechanical and chemical.

Mechanical weathering (or physical weathering, or disintegration) involves a reduction in the size of the rock and mineral particles but no change in the composition. Examples: Frost Action - water expands upon freezing and can exert tremendous pressures. Exfoliation - Rock that is formed deep underground is in equilibrium with high pressures. When these high pressures are removed (i.e. erosion), the stresses within the rock cause it to fracture into sheets or leaves that are parallel to the ground surface. Thermal expansion and contraction - almost all materials expand upon heating and contract upon cooling. This can cause internal stresses to build up and break down the rock. Different minerals expand and contract differently which results in stress along mineral boundaries. Abrasion - constant rubbing between surfaces. Animals (including humans) can mechanically break down rock.

Chemical weathering (or decomposition) involves a change in the composition of the material weathered. (Usually involves H2O, CO2, O2, and acidic water)

Examples: Dissolution - happens when solid material dissolves in water (i.e. it all becomes a solution). Oxidation - minerals can react with oxygen. A common example is "rusting" with iron-bearing silicate minerals. (olivine, pyroxene) Colors can include red, orange, and brown. (Carbonatization involves carbon dioxide as an chemical reactant.) Hydration involves the structural addition of water to a solid to form a hydrated solid product. Silicate minerals weather by hydration to form clay. An example:

2KAlSi3O8 (potassium feldspar)

+ H2O + 2H+ --> 2K+ + Al2Si2O5(OH)4 (clay)

+ 4SiO2

NOTE:

Feldspar - stable at high temperature and pressure

Clay - stable under conditions at the surface

The Rate of Weathering (in particular, chemical weathering) is proportional to the surface area of the material. Such that, a single rock with a volume of 100 cm3 will weather much faster if it is broken into 10 rocks each having a volume of 10 cm3. In fact, if we assume spherically shaped rocks

(total surface area of the 10 smaller rocks)/(total surface area of the single rock) = 2.17

Thus, the 10 smaller rocks will weather 2.17 times faster than the big rock.

The Rate of Weathering also depends on the composition of the rock or mineral. As a general "rule-of-thumb", minerals which crystallize at high temperatures and pressures are least stable and weather most quickly. Minerals that crystallize at lower temperatures and pressures are most stable to weathering at the surface. One can think this in the following way - minerals that are furthest from their "zone of stability" (or conditions in which they were formed), weather the fastest.

Soils from a Geological Perspective

Soil is generally defined as the unconsolidated material that consists of sand, clay, and decayed plant material (called humus) and exists near the surface.

Important note for the construction industry: The abundance and widespread presence of soil makes it an important topic to examine in the construction industry. Unless placed on rock, most structures must be founded on soil. Soil displays considerable variability in its characteristics and properties due to a variety of geological and biological factors.

Residual soils have developed in place on the bedrock from which they are derived. Other soils have been transported from elsewhere.

What governs the type of soil that will develop? 1. Parent Bedrock 2. Climate 3. Topology of the land 4. Time 5. Vegetation

There can be certain generalizations made about the "macroscopic" structure of soil (in particular, residual soils)

● The composition and particle sizes vary with depth.● There are visually recognizable zones (or horizons).

Soil Profile (starting at the surface and going deeper): (Horizon O - Contains humus on the ground surface, a large amount of organic matter, sometimes considered part of the A horizon) Horizon A - Considered the top soil, rich in organic matter, typically darker in color, also called the zone of leaching. The smaller soil particles migrate out of this horizon and into the deeper horizons in a process called eluviation. (Horizon E - very little clay particles and very little humus) Horizon B - Considered the subsoil, also known as the zone of accumulation, usually contains soluble minerals (particularly in arid regions) Horizon C - Weathered bedrock or disintegrating bedrock (Horizon R - bedrock, this is usually not classified as an horizon but simply rock)

Soil Profile Images

(Geologist have also broken down different soil profiles into soil orders.)

Water passing downward through soil can wash out and dissolve soil components. Eluviation is when smaller particles are

washed out of the top part of the soil and moved into the lower part. When soluble minerals are dissolved in the top part of the soil and precipitated out in the lower parts, it is called leaching.

An immature soil lacks any clearly developed horizons and resembles the parent material. Mature soils have fully developed horizons and is built-up.

A general classification of soils can be done based mainly upon the climate that has created the soil. Pedalfer - is a soil rich in aluminum and iron, they usually form in humid climates (Southeastern U.S.). Most of the residual soil in Wisconsin is a pedalfer. Pedocal - rich in calcium, usually form in arid climates (Southwestern U.S.), these soils often contain caliche. Caliche is a cemented layer of soil (quite hard). Laterite - derived from heavy weathering, depleted of almost all elements except aluminum and iron oxides, usually form in the tropics. Soils that form in the tropics are not rich in nutrients. Most of the nutrients come from the humus. If deforestation occurs and the soil dries out, it becomes hard and does not support plant growth well. Bauxite - (an extreme case of laterites)

Basic information on plant growth and soils (Large earthwork contracts sometime specify what characteristics the top layer of soil must have because it will be used for plant growth. The highway construction project just East of Menomonie on highway 29/12 kept the top soil separate from the rest of the soil that was moved. This top soil was layed down last on the re-graded slopes along the highway.)

County Extension office can perform a soil analysis for plant growth. This is a service (with a fee) that is mainly provided for the farmers. Soil Acidity (%H+ or PH level) has a strong effect on plant growth. If your soil is acidic you'll have to add lime. Soil may also be basic (base, OH). Plants require certain nutrients in the soil or their growth may be stunted. (P, K, Ca, Mg, B, Mn, Zn, etc.) Fertilizers usually provide nitrogen, phosphorous, and potassium. Listed as weight percents, such as: 5-10-5 or 10-10-10, respectively.

A glance at how a geologist, soil scientists, and soil engineers view soil:

UW-Stout library has a VHS tape on soils. From Rock To Sand To Muck: All The Dirt On Soils, Blue Sky Associates video Call Number: S591 .F76x 1996

Weathering - Related Web Links

Dr. Andy Frank's Physical Geology Weathering Dr. Pamela Gore's lecture notes on weathering Dr. Pamela Gore's lecture notes on soils Geology 41 at Duke University - Weathering (Part I and Part II) Richard Terry's Agronomy and Horticulture lecture notes on soils, slide show on soil horizons National Soil Survey Center (lots of good pictures) soil profiles, landscapes, land use National Soil Survey Center, Soil Science Education Website Huge list of web links and information on soils (WWW Virtual Library on Soils and Substrates) Iowa State Soil Judging Team Google - Search for Weathering Google - Search for Soils, Geology

Review Quizzes Section 5

Review Quiz Section 5 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapter Running Water, Groundwater, Mass Wasting, Weathering and Soils) Hydrology - Dr. Andy Frank's Practice Exam Mass Movement - Dr. Andy Frank's Practice Exam Weathering - Dr. Andy Frank's Practice Exam Streams - North Dakota State University Self-Test, Geology 120 Underground Water - North Dakota State University Self-Test, Geology 120 Mass Wasting - North Dakota State University Self-Test, Geology 120 Weathering - North Dakota State University Self-Test, Geology 120 Soils - North Dakota State University Self-Test, Geology 120

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 6 Engineering Properties of Soils Jump to: Lecture Notes, Web Links

Soil Cave-ins Jump to: Lecture Notes, Web Links

OSHA Regulations for Excavations Jump to: Lecture Notes, Web Links

Review Quizzes

Engineering Properties of Soils Engineering Properties of Soils - Lecture Notes

Rules for Professional Attitude by Karl Terzaghi, Another example of Karl Terzaghi being a very "down to earth" engineer

What is soil mechanics? Soil mechanics is the science of understanding and predicting how soil will respond to externally applied forces (or pressures).

Soils are usually cohesionless, cohesive, or organic. Cohesionless soils have particles that do not tend to stick together. Mostly composed of sand, maybe some silt.

Cohesive soils are characterized by very small particle sizes where surface chemical effects predominate. They are both "sticky" and "plastic". Organic soils are typically spongy, crumbly, and compressible. They are undesirable for supporting structures.

The grain size distribution (gradation curve) and consistency of a soil are two important physical measurements that are needed to determine the soil's suitability onto which a structure can be built. This "suitability" is usually identified by placing the soil into a classification using the USCS (Unified Soil Classification System).

Soil Characterization

Most soil classification systems used in construction classify soils based upon two experimental characterizations of soil. These two measurements are (1) a grain-size distribution curve (or gradation curve), and (2) the Atterberg limits (or soil consistency). The grain-size analysis can be either mechanical or with a hydrometer analysis. The mechanical method uses sieves with the standardized openings as shown in table 1.

3 in. (75mm) 2 in. (50mm) 1 ½ in. (38.1mm) 1 in. (25.0mm) ¾ in. (19.0mm)

3/8 in. (9.5mm) No. 4 (4.75mm) No. 10 (2.00mm) No. 20 (0.850mm) No. 40 (0.425mm)

No. 60 (0.250mm) No. 140 (0.140mm) No. 200 (0.075mm)

Table 1

The percent by weight of soil passing each opening is plotted as a function of the grain diameter (corresponding to a sieve number). The horizontal scale on this plot is logarithmic. The hydrometer method is based on Stokes' Law which indicates that a larger grain size will result in a larger terminal velocity

when dropping through a fluid (i.e. the larger size reaches the bottom quicker, assuming uniform density).

Homemade graduated cylinder that can be used as a hydrometer. (Made from a Jiffy peanut butter container.) I took a sample of soil from my backyard and placed it into the container with water. Shook it and let it set for a few hours. Out of ~150 mL of sample volume, about 125 mL is sand. There appears a clear boundary between the lighter colored sand and darker silt/clay (+organic matter). In general,

sand will settle out in about 30 seconds, silt in about 3 minutes, the balance of the volume is clay.

Consistency for a particular soil is defined by the water content present when it changes its response to stress. This measurement has been further refined by establishing Atterberg Limits. These limits divide four different "states" of consistency. If a soil is heavily saturated with water and then is dried out, it will move from a liquid state to a plastic state to a semisolid state and then to a solid state. The dividing line between the liquid and plastic states is the liquid limit (LL). The dividing line between the plastic and semisolid states is the plastic limit (PL). And the dividing line between the semisolid and solid state is the shrinkage limit (SL). This is shown in figure 1.

Figure 1

The plastic index (PI) is the range of the plastic region. These limits are expressed as a percent of moisture content. The experimental measurement of these limits requires a "liquid limit device". More specifically, it is a device that measures the water content at which the shear strength of the soil becomes so small that the soil "flows" to close a standard groove cut in a sample of soil when it is jarred in a standard manner. (Come to think of it, this is strikingly similar to how I would characterize my young children's diaper contents!)

Classification Systems

The two most widely used classification systems are the American Association of State Highway and Transportation Officials (AASHTO) and the Unified Soil Classification System (USCS). In this class, we will mainly discuss the USCS system that is used by engineering consulting companies and soil-testing laboratories. The following group symbols are used in USCS:

G Gravel S Sand M Silt C Clay O Organic PT Peat W Well graded P Poorly graded L Low liquid limit compressibility; lean (clay) Low liquid limit; (silts); plasticity H High liquid limit, compressibility; fat (clays) High liquid limit; elastic (silts)

USCS Chart and Plasticity Chart

Note: The amount of Fines in a soil sample is the percent by weight that passes a number 200 sieve.

Soil Classification Systems USCS (Unified Soil Classification System) - classifies soils using grain-size, liquid limit, and plasticity index. Applies these measurements to a chart to determine group symbol. AASHTO (American Association of State Highway and Transportation Officials) - uses grain-size, liquid limit, and plasticity index. The measurements are plugged into a formula to determine a group index. The lower the GI, the better the soil is for use as a subgrade.

GI (group index) = (F-35)[0.2+0.005(LL-40)] + 0.01(F-15)(PI-10), F = % fines

Soil Texture Triangle from Iowa State (includes comparision between AASHTO and USCS)

Important Physical Parameters of Soils

Soils contain three components, which may be characterized as solid, liquid, and gas. The solid components of soils are weathered rock and (sometimes) organic matter. The liquid component of soils is almost always water (often with dissolved matter), and the gas component is air. The volume of water and gas is referred to as the void. The following are important relationships between these quantities. The notation will follow V(total), Va(air), Vw(water),

Vs(solid), and Vv(void), where the V stands for volume. The same notation is used for W (weight) and M (mass).

Name Equation Description

Void Ratio Ratio of the void volume to the solid volume.

PorosityPercent of the total volume that is taken up by the void.

Degree of Saturation Percent of the void that is taken up by the water.

Water ContentPercent of the weight of water to the weight of solids.

Unit WeightTotal density of the soil. Includes solids and the void.

Dry Unit Weight Density of the soil when it is completely dried out.

Unit Mass, Dry Unit Mass Density of the soil and the dry density of the soil.

Specific Gravity of Solids

Ratio of the density of solids to the density of water.

Note:

Other Important Relationships: W=Ws+Ww

V=Vs+Vv=Vs+Vw+Va

A graphical presentation of soil properties

In general, soil properties are simply physical relationships between mass and volume.

Examples in Relating Soil Properties

In granular soils, compressibility and shear strength are related to the compactness of the soil grains. For a soil in its densest condition, its void ratio is the lowest and it exhibits the highest shear strength and the greatest resistance to compression. The compactness can be evaluated quantitatively by the relative density (Dr) which has the form

The values of γmin or emax for a given soil can be determined by drying, pulverizing, and pouring a sample into a container. The values γmax or emin for

are found by subjecting this dry sample to prolonged vibrations and loads. The gamma variables above refer to the dry unit weight.

The basic behavior of soil (in fact, the graphs below sums up most of soil mechanics in the qualitative sense).

Soil exploration and sampling has three basic aspects.

Boring (or drilling, or digging) Auger produces a disturbed sample. Wash Borings uses water to bring the soil to the surface. Core Boring can provide a sample of hard material. Cores can also sample soil from large depths. Sampling (remove soil from the hole, sample should be well marked with date, location, and depth) Testing (a test pit can be used to obtain an undisturbed sample.)

Disturbed Sample has been "disturbed" and no longer has the same form (i.e. density). The grain size, liquid limit, plastic limits, specific gravity, and some compaction tests can be performed on this sample. Undisturbed Sample (as close to undisturbed as possible) keeps the same form or condition it had when in the ground. One can perform all the tests as a disturbed sample plus strength, compressibility, and permeability.

General rules: soil should be checked every 75 ft (multi-story), ~150 ft (one story), ~750 ft (highway), reduce distances if non-uniformity is encountered. For OSHA excavation regulations, soil testing is done mainly to determine the stability of excavation sides.

The depth should be to a soil strata of acceptable bearing capacity (if this is shallow, check sub-strata). In general, in cohesive soils the test should go down to a point where the increase in stress due to foundation loading is < 10% the overburden pressure (overburden pressure is defined below).

The overburden pressure is the effective pressure of the overlaying soil. Such that, if a soil sample has been taken at a depth of 10 ft and the unit weight of the soil is 110 lb/ft3, the overburden pressure is P = γh or P = (110)(10) = 1,100 lb/ft2. (Provided this soil has not "seen" or had a history of any higher overburden pressure - which could be encountered for heavily eroded surfaces.)

Shear Strength of Soil and Laboratory Tests

There are three general ways to induce deformations in solids or semi-solids: tension, compression, and shear.

Soil is not capable of resisting tension, it is capable of resisting compression to some extent. In cases of excessive compression, failure usually occurs in the form of shearing along some internal surface within the soil.

Structural strength of soil is primarily a function of its shear strength, where shear strength refers to the soils ability to resist sliding along internal, 3-dimensional surfaces within a mass of soil.

Soil strength comes from internal friction and cohesion. It follows the formula

s=c+σtan(ϕ)

where s = shear strength, c = cohesion, σ = effective intergranular normal (to the shear plane) pressure, and ϕ = angle of internal friction. The quantities

s, c, and σ have units of pressure.

So what does this equation mean? The shear strength of a heavy clay soil does not increase with increased load because ϕ = 0. The shear strength of a very sandy soil does increase with increasing load because ϕ does not equal 0, but c = 0 for sand. Most soils are a mixture of sand and clay. The following graph illustrates the results of the equation above.

The unconfined compressive strength is, under most conditions, twice the cohesion of clay soils (mathematically: qu=2c). This will be important to

remember when using tools to test a soil's stability to satisfy OSHA requirements.

Three widely used laboratory tests

Unconfined Compression Test - An axial load is placed onto a sample, the load is increased until (a) the soil fails, or (b) 15% strain has occurred. This load is known as the unconfined compressive strength. There is no lateral support on the soil sample for this measurement.

(click to enlarge)

Direct Shear Test - A shear stress is placed on the soil sample. The stress is increased until failure. Several of these tests will provide an experimental measurement for c and ϕ for a given soil. (In the formula s=c+σtan(ϕ).)

(click to enlarge)

Triaxial Compression Test - Same as the unconfined compression test but with the addition of lateral pressure.

(click to enlarge)

Two widely used field tests

Pocket Penetrometer - Measures the unconfined compressive strength.

Shearvane (or Torvane) - Measures the cohesion.

Here is a close-up view of the dial.

These tools will be talked about in class. They are acceptable ways to measure the strength of the soil to satisfy OSHA regulations when determining proper sloping.

Engineering Properties of Soils - Related Web Links

Compaction Research Plan that utilizes gradation curves and soil properties Soil classification lecture from University of Alaska-Anchorage Geotechnical Properties of Geologic Materials (includes USCS chart) Apollo Soil Mechanics A list of internet resources for Geotechnical Engineering Soil mechanics laboratory activities from Tristate University (Sieve Analysis, Atterberg Limits, Direct Shear, Hydrometer Analysis, Sandcone Analysis, Constant Head Permeability, Standard Proctor Test, Unconfined Compression Test, Consolidation Test) Cohesive Soil: A Dangerous Oxymoron by J. Carlos Santamarina, Dept. of Civil Eng., GA Institute of Technology Electronic Journal of Geotechnical Engineering Engineering Geology by John Duffy and Jeffrey Keaton, Overview of engineering geology in the 21st century. Google - Search for Soil Mechanics Google - Search for Engineering, Soil Properties

Google - Search for Unified Soil Classification System Google - Search for Soil Plasticity, Soil Consistency

Soil Cave-ins Soil Cave-ins - Lecture Notes

The survivor said "All day he had been asking me, 'If this caves in, where are you gonna go?' I asked him this morning, let's get some boards to shore this thing up and he said, 'We're almost done.' In five more minutes we would have been sitting at the table eating lunch.". . . . . It took firefighters an hour to reach the man's wrist and determine he was dead. It took them another five hours to pull his body from the trench.

- Los Angeles Times, June 24, 1993, "Laguna Beach Man Killed in Trench Cave-In"

As some 50 rescuers worked with buckets and hand shovels to free him, a man buried up to his head talked with them and even joked a little about his predicament. However, after about four hours, the man suddenly quit talking, and died. Officials speculated he may have succumbed to internal injuries and bleeding. He was working in an unshored 15-foot-deep trench to install a sewer line when the accident happened.

- Cave-in : 10/10/96, Cuyahoga Falls, OH

Buxton, N.C. (1998) A man died on a beach when an 8-foot-deep hole he had dug into the sand caved in as he sat inside it. Beachgoers said Daniel Jones, 21, dug the hole for fun, or protection from the wind, and had been sitting in a beach chair at the bottom Thursday afternoon when it collapsed, burying him beneath 5 feet of sand. People on the beach on the Outer Banks used their hands and shovels, trying to claw their way to Jones, a resident of Woodbridge, VA., but could not reach him. It took rescue workers using heavy equipment almost an hour to free him while about 200 people looked on. Jones was pronounced dead at a hospital. You just wouldn't believe the outpouring of concern, people digging with their hands, using pails from kids," Dare County Sheriff Bert Austin said.

Long lists (1) of cave-in accidents.

The Antlion - An insect that has evolved an instinctual sense of slope stability and excavation failure. It uses this sense to catch prey in the bottom of a sand pit. If the field of excavation needed a mascot, this insect is a grotesque looking selection that would be appropriate.

___________________________________________________________________

Anatomy of a Cave-in

How dangerous is soil? Soil is heavy! It can exert a very large amount of pressure and be extremely forceful when moving!

A reasonable unit weight of soil is 120 lb/ft3. This corresponds to 3,240 lb in every cubic yard - most cars don't weigh this much! Would you be willing to have a Chevy car dropped 4 feet onto your body? How about 1 foot? How about if it is gently placed onto your chest?

Excavation Cave-in Animation

The column of soil marked 3 begins getting subjected to an unconfined compression strength "test" at its base. This is where the soil, many times, fails first and is marked with a 1. The next section to fail is 2 then 3. Cracks (or tension cracks) appearing in the ground next to an excavation are indications that the sides may not be stable and are pulling away! (But cracks don't have to appear for a cave-in to occur.)

Note: This description of a soil cave-in follows a common sequence of events. But some cave-ins may not follow this particular sequence. In fact, parts 1, 2, and 3 could all fail at once.

Often a worker can be trapped by a first cave-in and fellow workers will jump, willy nilly, into the trench to help! This may put the rescuers in harms way. There is at least one cave-in on record where 2nd and 3rd cave-ins have occurred "catching" separate groups of rescuers.

Statistics: 50% of all excavation fatalities are rescuers, an excavation accident is 15 times more likely to result in death than any other construction accident, 8/10 of all deaths occur in < 15ft, 4/10 of all deaths occur in < 10ft, between 100-400 people are killed per year in excavations, 1,000-4,000 are

injured every year

So why do these "accidents" occur? Possible reasons include: 1. Attempting to save $$ (and time) by not properly sloping or shoring. 2. Boss has requested you get down into an unsafe trench. You don't want to "rock the boat" or get your boss mad by refusing. 3. It is "wimpy" to be afraid of dirt. This is the so-called "cowboy-ish" effect. This is closely related to peer pressure to do the job and not worry about the safety aspects. 4. Not being educated on the hazards of a potential cave-in.

Co-workers may be consulted or assist professional emergency response personnel during a rescue. A problem arises when co-workers are emotionally connected to the victim and become rash and irresponsible when trying to rescue them.

A good bottom-line philosophy on excavation safety: It is very risky to cut corners on excavation safety. One accident and there will be law suits, fines, penalties (possible prison time) not to mention personal grief and trauma of losing a co-worker or getting one seriously injured. One accident can put you out of business. For the long-term financial and emotional health of your business and co-workers, it is best to follow safety regulations.

Is this a safe situation? Notice the huge tension cracks developing in the soil behind the worker. Why is the worker putting themselves into harms way? There is no sloping or retaining structure for the soil behind the worker.

Here is another risky situation. This picture is from the Pioneer Press, 9/9/01.

Actual Accident Site Picture (1956)

Soil Cave-ins - Related Web Links

Center to Protect Workers rights fact sheet on trench safety A long list of excavation accidents reported in the newspapers University of Iowa warning about trench cave-ins. Google - Search for Soil Cave-Ins or Soil Collapse

OSHA Regulations for Excavations OSHA Regulations - Lecture Notes

*This document is not intended as a complete and comprehensive statement of all regulations. It is only an abbreviated summary of selected sections. Click here for the complete OSHA description of excavation regulations.

UW-Stout library has an excavation safety seminar on VHS tapes and guide book. Excavation Safety Seminar, American Society of Civil Engineers Call Number: TA730 .E93x 1995

The Bureau of Labor Statistics reports (based upon claims made to workers compensation) that between 1976 and 1981 the deaths associated with work in excavations accounts for nearly 1% of all annual work related deaths. These statistics also indicate that excavation accidents caused about 1,000 work-related injuries each year and about 140 result in permanent disabilities and 75 in death. These statistics are rather old and have probably increased. If one takes this figure of deaths and assumes they are evenly distributed about the 50 states with about 50 excavation companies per state, then approximately one of your co-workers will die from an excavation accident in a 30 year construction career and many more will get injured. By knowing and adhering to OSHA regulations, the risks can be greatly reduced. The OSHA standards regulate the use of support systems, sloping and benching systems and other systems of protection as a means of protection against excavation cave-ins. In addition, the standards regulate the means of access to and egress from excavations, and employee exposure to vehicular traffic, falling loads, hazardous atmospheres, water accumulation, and unstable structures in and adjacent to excavations.

"Cave-ins are not the only excavation danger. Undetected underground utilities, water accumulation, hazardous atmospheres, loose rock and soil, and even creatures, such as snakes, are a threat. In all these situations, prevention is the key."

Prevention: The Ultimate Solution To Excavation Safety by Jerry Woodson, J.J. Keller and Associates, Inc., Neenah, WI

(This quote first appeared in the February 1998 Issue of Utility Safety Magazine)

Basic Terminology Excavation: Any artificial (man made) cut, cavity, trench, or depression in an earth surface, formed by earth removal. Trench: A narrow excavation in which the depth is greater than the width, but the width of a trench is not greater than 15 feet. Shoring: Is a structure or system (usually made of metal or timber) that supports the sides of an excavation and which is designed to prevent cave-ins. It is sometimes a pre-engineered shoring system comprised of aluminum hydraulic cylinders (crossbraces) used in conjunction with vertical rails (uprights)

or horizontal rails (walers). Used to prevent cave-ins. Failure: This term refers to the breakage, displacement, or permanent deformation of a structural member or connection so as to reduce its structural integrity and its supportive capabilities. Competent Person: Is a person who is capable of identifying existing and predictable hazards in the surroundings, or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has the authorization to take prompt corrective measures to eliminate them.

Tabulated Data are tables and charts approved by a registered professional engineer and used to design and construct a protective system. Soil Terminology Cemented soil: Is a soil in which the particles are held together by a chemical agent, such as calcium carbonate, such that a hand-size sample cannot be crushed into powder or individual soil particles by finger pressure. Cohesive soils: Is a clay, or a soil with a high clay content, which has cohesive strength. Cohesive soil does not crumble, can be (note: "can be" is not the same as "should be") excavated with vertical sideslopes, and is plastic when moist. Cohesive soil is hard to break up when dry, and exhibits significant cohesion when submerged. Cohesive soils include clayey silt, sandy clay, silty clay, clay and organic clay. Fissured: Is a soil material that has a tendency to break along definite planes of fracture with little resistance, or a material that exhibits open cracks, such as tension cracks, in an exposed surface. Granular: Is a soil that is mainly composed of gravel, sand, or silt with little or no clay content. Granular soil has no cohesive strength. Some moist granular soils exhibit apparent cohesion. Granular soil cannot be molded when moist and crumbles easily when dry. Soil Type Stable Rock: Is a natural solid mineral matter that can be excavated with vertical sides and remain intact while exposed. Type A: Is a cohesive soil with an unconfined compressive strength of 1.5 ton per square foot (tsf) - in SI units, 144 kPa (1 Pa = 1N/m2), or greater. Examples: clay, silty clay, sandy clay, clay loam, hardpan, cemented soils. No soil will be considered Type A if: the soil is fissured, subjected to vibration, was previously disturbed, is part of a sloped layered system sloping into the trench, or is seeping water. Type B: Cohesive soil with an unconfined compressive strength greater than 0.5 tsf (48 kPa) but less than 1.5 tsf (144 kPa). Examples: angular gravel (similar to crushed rock), silt, silt loam, previously disturbed soils unless otherwise classified as C, dry unstable rock, some sloped layered systems. Type C: Cohesive soil with an unconfined compressive strength of 0.5 tsf (48 kPa) or less. Examples: granular soils including gravel, sand, and loamy sand; any submerged or soil with freely seeping water, and any soil not otherwise classified.

Where soils are configured in layers, i.e. they have different geological structures, the soil must be classified on the basis of the soil classification of the weakest soil layer. Each layer may be classified individually if a more stable layer lies below a less stable layer. General Excavation Area Safety Daily inspections of an excavation area shall be done by a competent person. This should be done prior to work and after a rainstorm, and as needed throughout the shift. The atmosphere shall not be (1) oxygen deficient, (2) Explosive/flammable/oxidizing, or (3) toxic (poisonous, corrosive, irritating). There are many situations where hazardous gases can build within an excavation (e.g. welding/burning, chemical usage) Surface Encumbrances: All hazards shall be removed, secured, or safeguarded. This includes, but is not limited to, sharp, blunt, and heavy objects. Also included are holes, wells, pits, shafts, cables, and any equipment that could pose a hazard. Underground Installations: Utilities must be located prior to excavations. Utility companies shall be contacted in advance. If work proceeds near the utility, the installation shall be located by a safe means. Unearthed utilities shall be supported. Newspaper articles about underground utilities being damaged. Access and Egress: A ladder, ramp, or stairway shall be provided in trench excavations that are 4 feet or more in depth, so as to allow no more than 25 feet of lateral travel. Walkways/bridges that cross over excavations shall have standard guardrails. Ladders must be secured and extent at least 36 inches above the landing.

Water Accumulation: Surface water shall be diverted away from trench. Employees shall be removed from a trench during a rain storm. All employees that are exposed to vehicular traffic shall wear warning vests. No one shall work underneath a suspended load. Mobile Equipment Approaching Edge of Excavations: Warning signals (logs, hands or mechanical signals, barricades, etc.) must be used when the operator does not have a clear and direct view of the edge. Loose Rock or Soil: The placement of excavated materials (spoil) shall be a minimum of 2 feet from the edge of excavation or have a sufficient retaining device. Soil Classification and Sloping Each employee in an excavation shall be protected from cave-ins by an adequate protective system. One has the following options to provide this protection: sloping and benching, sloping with supports and shields in lower portion, timber shoring, aluminum hydraulic shoring, trench shields. What must be done to select the proper protection depends on the depth of the excavation and the soil type. Here is an outline of the steps needing to be followed to meet OSHA guidelines: I. A competent person must make one visual and one manual analysis of the soil. Layered systems should be classified according to their

weakest layer. Reclassification must be done if conditions change.

Visual Tests Excavated soil and soil in excavation sides: fine-grained soil is cohesive, sand or gravel is granular. Soil as it is excavated: clumps indicate cohesive soils, easily broken soil is granular. Sides of excavation and adjacent area: fissured material, layered systems, surface water or seepage, sources of vibration, previously disturbed soil, etc.

Manual Tests (Detailed Description) Plasticity (or ribbon test): Cohesive soils stick together. Dry strength: dry, granular soil crumbles easily; dry soil which is difficult to break is probably clay. A drying test is used to determine if soil is fissured, unfissured, or granular. Thumb penetration: Type A soil is readily indented by thumb with great effort; Type B if the only the thumbnail penetrates; Type C soil is easily penetrated several inches by thumb and can be molded by light finger pressure. Pocket penetrometer: Determines unconfined compressive strength. Shearvane: Determines soil cohesion II. Determine the Sloping and Benching Diagram of proper sloping and benching ( Type A, Type B) Classify Soil (Type A, B, or C) Determine Maximum Allowable Slope

Soil TypeMaximum Allowable Slope

(Horizontal Distance:Vertical Distance)

Solid Rock vertical sides

A* 3/4H:1V

B 1H:1V

C 3/2H:1V

*One exception: Simple slope excavations in soils of type A which are open 24 hours or less (short term) and which are 12 feet or less in depth shall have a maximum allowable slope of 1/2H:1V.

Slopes and benches for excavations deeper than 20 feet must be designed by a registered professional engineer.

Reducing Actual Slope Signs of distress or surcharge loads (operating equipment, stored material, etc.) III. Shoring Classify Soil Determine proper shoring design Timber shoring Aluminum hydraulic shoring Pneumatic/Hydraulic shoring Trench or Screw Jacks Trench shields and Boxes, Stacked Trench Shields Slope and Shielding Configurations (Type A, Type B, Type C)

UW-Stout Pocket Guide to Excavation Safety This is a graphics file with a resolution of 200 pixels per inch. Quality can be optimized if you are using a color printer with a resolution greater than or equal to 200 pixels per inch. The image will be larger on your computer monitor than it will be when printed out. [*The final dimensions of the folded pocket guide should be 5.3 cm x 8.7 cm. Some computer systems have not been printing the guide to its proper dimensions. You may need to

download the graphics file and shrink its size with a software package such as Paint or Imager.] Procedure to use it: 1. Download the image. 2. Cut along the solid outside lines. 3. Fold (or cut) along the dashed line that divides the document in half. 4. Adhere the bottom half to the back of the top half (scotch tape works good). You might want to make sure that it is right side up so that the final three-fold document can be easily read. 5. Fold along the dashed lines that divide the document (width wise) into thirds. Fold slightly (~1mm) to the right of the right side dashed line to optimize fold. The EXCAVATORS POCKET GUIDE cover should be on the outside. 6. Laminate the pocket guide if you want it to have a long life. The pocket guide also comes in JPG, EPS, PDF formats. (Disclaimer: This pocket guide does not contain complete and comprehensive information. Permission is granted to use this guide for all non-profit activities.)

OSHA Regulations - Related Web Links

Excavation Safety Seminar (VHS tapes) - UW-Stout Library, Call Number TA730 .E93x 1995 main stacks

Diggers Hotline On-line, Wisconsin Law, locating underground utilities, etc. Trench Shoring Services (a company that deals with shoring equipment) Excavation and Trenching Safety Trenching and Excavation Safety OSHA Documents on the web: Construction Resource Manual, Technical Manual, OSHA regulations on excavations, Construction Fatalities (statistics, pdf file format), OSHA Excavations (the entire document, pdf file format) Canadian Excavation Standards and Procedures Trenching & Excavations: Safety Principles, the National Ag Safety Database, Ohio State University Virginia Tech's Excavation Trenching & Shoring Program. This web site also has a project manager's manual and worker's manual (both are Word v6 doc files). Trenching and Shoring Procedures from the Oklahoma State University Environmental Health & Safety Trench Safety Tutorial (and construction links) by Michael Hein, Assoc. Prof., Building Science Department, Auburn University

MSHA (Mining Safety and Health Administration) home page, Mining safety fact sheet, Mining Safety and Health Act of 1977 (everything you wanted to know about hazards of mining) UW-Stout Safety and Industrial Hygiene WWW links Excavation Cave-ins Are The Pits, Eagle Insurance Group Google - Search for Excavation Safety

Review Quizzes Section 6

Review Quiz Section 6

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 7 Compaction Jump to: Lecture Notes, Web Links

Dewatering Jump to: Lecture Notes, Web Links

Stress and Settlement Jump to: Lecture Notes, Web Links

Foundations Jump to: Lecture Notes, Web Links

Pilings Jump to: Lecture Notes, Web Links

Review Quizzes

Compaction Compaction - Lecture Notes

Soil is extensively used as a basic material of construction. For example: dams, dikes, embankments, ramps, etc. The advantages of using soil are that it (1) is generally available everywhere, (2) is durable - it will last a long time, and (3) has a comparatively low cost.

It is typically placed in layers (sometimes called lifts) with each layer being compacted to develop a final elevation and/or shape.

Why Does It Need Compacted?

Compaction increases a soils density. This produces the following effects: 1. increases the soil's shear strength 2. decreases future settlement 3. decreases the soil's permeability (also a function of soil type) 4. stable against volume change as water content or other factors change 5. relatively durable and safe against deterioration

It is most appropriate to talk about a compaction energy. The compaction energy given to a soil is proportional to the pressure, speed of rolling, and the number of times it is rolled. A unique aspect of soil is encountered when one wants to maximize the density but minimize the compaction energy - which makes good business sense. For a given compaction energy, there is an optimum water content that will obtain a maximum dry density. Too little or too much water content will cause a smaller dry density. The water acts as a lubricant and allows the soil particles to squeeze together more easily.

The Standard Proctor Test is a laboratory test used to determine the optimum water for a given compaction energy, for a given soil. The graph below illustrate the results obtained from a Standard Proctor test:

Quick glance at the Standard Proctor test procedures (ASTM D 1557): (1) dry sample until friable (easily crumbled) with trowel (2)

prepare at least 4 samples using the same soil but different moisture contents (3) wait for a specified curing time (4) compact (gives a standard energy/vol) (5) measure γ and ω.

Types of compactors (machine images courtesy of Bomag GmbH)

Hand Compactor (motorized and non-motorized)

Walk Behind Roller

Walk Behind Vibratory Plate

Walk Behind Double Smooth Roller

Towed Single Roller (Vibratory or non-vibratory)

Smooth Roller (Many times vibratory)

Smooth RollerPneumatic Roller (smooth rubber tires)

"Sheepsfoot" (Protrusions stick out from smooth roller, can supply pressures in excess of 600 psi or 4200 kN/m2)

Grader (Not a compactor, but often used in conjunction with compactors)

Heavy Compactor/Bulldozer (also a "Sheepsfoot" compactor)

Soil type, water content, and type of compactor are factors that need to be considered when compacting. Compaction is often used when fill (disturbed soil from another location and transported) is used at a construction site. This implies you may be using self-propelled scrapers (earth movers), bulldozers, and graders. An earthcut or "borrow" is popular to use. A borrow is simply a hole dug (usually near the construction site) so that soil from this hole is used elsewhere as fill.

Borrows and fill dirt being used at a construction site. Notice the darker top soil with the lighter subsoil.

Rules of Thumb For Compacting Soils: I. Granular soils can be compacted in thicker layers (or "lifts) than silt or clay. II. Fill placed underwater (or requiring good drainage properties) should consist of granular or coarse material. III. Check to make sure natural soil is adequate for supporting compacted fill. This can be tested by rolling over it with a heavy piece of equipment and observing compaction characteristics (called "proof-rolling"). IV. Cohesionless soils usually need kneading, tamping, vibratory compacting. (Note: kneading is defined as working by folding.) Cohesive soils usually need kneading, tamping, or impact. Heavy cohesive soils can sometimes require dynamic compacting that uses large weights dropped from heights or underground dynamite with directed explosions.

Compaction Control Field Testing: 1. Sand Cone - requires hole excavated, weigh the soil removed and determine the volume of the hole with sand. This is done by filling the hole with a sand of known density. 2. Washington Densometer - requires hole excavated 3. Oil Replacement - requires hole excavated, weigh the soil removed and determine the volume of the hole with a device with an expandable rubber membrane 4. Nuclear Densometer - uses a radioactive source and "counter" to determine soil density. This method has fast results with the potential for a large number of tests in a short time. It is usually calibrated with the Sand Cone method.

Compaction Characteristics and Soil Grouping in USCS

Group SymbolCompaction

CharacteristicsCompressibility and

ExpansionValue as Embankment

MaterialValue as Subgrade

Material

GW Good Very Little Very Stable Excellent

GP Good Very Little Reasonably Stable Excellent to Good

GM Good Slight Reasonably Stable Excellent to Good

GC Good Slight Reasonably Stable Good

SW Good Very Little Very Stable Good

SP Good Very LittleReasonably Stable when Dense

Good to Fair

SM Good SlightReasonably Stable when Dense

Good to Fair

SC Good to Fair Slight to Medium Reasonably Stable Good to Fair

ML Good to Poor Slight to MediumPoor, gets better with high density

Fair to Poor

CL Good to Fair Medium Stable Fair to Poor

OL, MH, CH, OH, PT Fair to Poor High Poor, Unstable Poor to Not Suitable

Compaction - Related Web Links

Compaction Meter - A new device on the market that measures the strength of impulses transmitted through the soil as a function of compaction. Marcel Equipment Limited (company that sells used compactor equipment) Bomag GmbH (company that sells compactor equipment) Standard Proctor test equipment Google - Search for Soil Compaction

Dewatering Dewatering - Lecture Notes

When soil is excavated below or near the water table, pumps will usually be used to dewater the site. This involves creating a drawdown curve (or cone of depression) that is below the base of the excavation. Factors that are important include soil permeability, depth of water table, depth (and geometry) of excavation.

Single stage dewatering

The above diagram illustrates a dewatering technique using small trenches dug around the perimeter of the excavation. One can estimate the pumping requirements based upon the formula

(reference: Soils In Construction, W.L. Schroeder, S.E. Dickenson, Prentice Hall 1996, pg. 162). The value D represents the radius of influence, H is the depth to an impermeable layer from the original water table, ht is the height of the water level in the interceptor ditch

with respect to the impermeable layer, k is the soil's permeability, and q is the pump per unit length of ditch. A more elaborate two-stage dewatering technique is shown in the diagram below.

Multi-stage dewatering

As a general rule, when the excavation is deep (with respect to the water table) and the soil is very permeable (i.e. gravel or sand), a high pumping rate will be required. For an excavation that extends just slightly below the water table and the soil is somewhat impermeable (i.e. clay or silt), a lower pumping rate is required. Be careful, the depth of a water table varies as a function of time for any given site! This means that the depth of the water table varies with seasons or possibly local precipitation.

Drawdown curve for an excavation site with two pumps.

Create a 3-dimensional graph of a drawdown surface using with an Excel spreadsheet with up to 20 dewatering pumps. (This requires you to have Microsoft Excel 97 on your computer. A fast computer is also preferable.)

Dewatering - Related Web Links

Griffin Dewatering Corporation (lots of dewatering techniques and explanations) Google - Search for Dewatering Excavation

Stress and Settlement

Stress and Settlement - Lecture Notes

A strange case of Palace of Fine Arts in the Alameda area of Mexico City. Built sometime between 1900 and 1934, it was a magnificent and strongly built structure. It was built on grade, level with the square and other buildings nearby. But because of loose sand permeated with water in the subsurface, the massive structure sunk 6 ft into the ground! (Luckily, it settled evenly minimizing structural damage.) Believe it or not, in the 1960's the building moved again. This time it moved 12 ft up! The weight of skyscrapers being built around the Palace had pushed the subsurface water and soil around sufficiently to raise the building. (Source: Why Buildings Fall Down, M. Levy and M. Salvadori, WW Norton & Company, 1992)

The Milwaukee Metropolitan Sewerage District (MMSD) agreed to a $24 million settlement in a claim against the engineering firm CH2M Hill. MMSD claimed the engineering firm mis-judged the weak bedrock and potential for flooding in the designs of a 5.3-mile North Shore deep tunnel project. This project was designed to store raw sewage during rain-storms and snow melts, preventing the polluted water from fouling the area's rivers and Lake Michigan. MMSD also agreed to pay $3.5 million to settle claims from downtown businesses. These businesses claimed water pouring into the tunnel drained ground water under downtown businesses, causing building foundations, walls, sidewalks and sewer connections to crack. (Source: Milwaukee Journal Sentinel, December 5, 1998)

Worlds oldest building code, the Code of Hammurabi.

Settlement and Consolidation of Soils

Any structure built on soil is subject to settlement. Some settlement is inevitable and, depending on the situation, some settlements are tolerable. When building structures on top of soils, one needs to have some knowledge of how settlement occurs and predict how much and how fast settlement will occur in a given situation.

Important factors that influence settlement:

● Soil Permeability● Soil Drainage● Load to be placed on the soil● History of loads placed upon the soil (normally or over-consolidated?)● Water Table

Settlement is caused both by soil compression and lateral yielding (movement of soil in the lateral direction) of the soils located under the loaded area. Cohesive soils usually settle from compression while cohesionless soils often settle from lateral yielding - however, both factors may play a role. Some other less common causes of settlement include dynamic forces, changes in the groundwater table, adjacent excavations, etc. Compressive deformation generally results from a reduction in the void volume, accompanied by the rearrangement of soil grains. The reduction in void volume and rearrangement of soil grains is a function of time. How these deformations develop with time depends on the type of soil and the strength of the externally applied load (or pressure). In soils of high permeability (e.g. coarse-grained soils), this process requires a short time interval for completion, and almost all settlement occurs by the time construction is complete. In low permeable soils (e.g. fine-grained soils) the process occurs very slowly. Thus, settlement takes place slowly and continues over a long period of time. In essence, a graph of the void ratio as a function of time for several different applied loads, provides an enormous amount of information about the settlement characteristics of a soil.

Terminology

Pressure (or load) is defined as the amount of weight being distributed over an amount of area. Mathematically: .

Overburden pressure is the effective pressure (sometimes referred to as effective weight) of the overlaying soil. This can be calculated according to the formula P=γh where γ is the unit weight of overlaying soil and h is the depth.

Normally consolidated clay has never been subjected to any loading larger than the present effective overburden pressure. The height of the soil above the clay has been fairly constant through time.

Overconsolidated clay has been subjected at some time to a loading greater than the present overburden pressure. This type of clay is generally less compressible.

Coefficient of consolidation, cv, is a measure of how fast and how much a sample of soil will deform under a load. A large value

indicates a fast consolidation and a low value indicates a slow consolidation.

Estimating Settlement in Clay and Sand

How fast does the soil settle?

The process of obtaining a quantitative prediction of how much a soil will settle and how fast begins with examining a plot of soil deformation as a function of time for a given load. The soil deformation will correspond to a void ratio. Figure 1 shows such a plot.

Figure 1

Primary consolidation of the soil happens before point A on the graph. The secondary consolidation happens after point A and is characterized by a very slow settlement. The coefficient of consolidation, cv, for a particular loading is related to the shape of this graph

and is defined as

(1)

where H is the thickness of the test specimen at 50% consolidation, and t50 is the time to 50% consolidation. One can use this parameter

to calculate the time rate of settlement with equation 2 and figure 2. The time, t, to reach a particular percent of consolidation is

(2)

where H is the thickness of the consolidating layer, Tv is a time factor that depends of the percent consolidation and is obtained from

figure 2, and cv is the coefficient of consolidation.

Figure 2

How much will the soil settle?

Figure 3

Now, to calculate the total settlement due to primary consolidation, we need to introduce the equation (derived from figure 3):

(3)

where S = total settlement due to primary consolidation, eo = initial void ratio of the soil in situ,

e = void ratio of the soil when subjected to a total pressure (p), H = thickness of the consolidating clay layer (if the cohesive soil layer is underlain by sand and gravel then use ½H for the thickness and use H if underlain by bedrock) , p = total pressure acting at midheight of the consolidating layer, po = present effective overburden pressure at midheight of the consolidating layer.

The constant Cc is the compression index and is equal to the slope of the curve indicated in figure 3. Its value can be calculated by

(4)

with the variables defined the same as in equation 3.

Example: Consider an 8 ft clay layer beneath a building that is overlain by a stratum of permeable sand and gravel and is underlain by impermeable bedrock. The total expected consolidation settlement for the clay layer due to the footing load is 2.5 in. It is also known from laboratory tests that cv=2.68x10-3 in.2/min.

Find: (1) How many years it will take for 90% of the total expected consolidation settlement to take place? (2) What amount of consolidation settlement will occur in 1 yr.?

(1) t = (Tv/cv)H2

Tv = 0.848 (using U = 90% in figure 2)

H = 8ft(12in/1ft) = 96 in t90 = ( (0.848)(96in)2 )/(2.68x102 in2/min) = 2.9x106 min

or 2.9x106 min (1hr/60min)(1d/24hr)(1yr/365d) = 5.5 years

(2) Work part one in reverse: t = (1yr)(365d/1yr)(24hr/1d)(60min/1hr) = 5.26x105 min Tv = (tcv)/H2 = ( (5.26x105 min)(2.69x10-3 in2/min) )/(96in)2 =

0.15 Tv = 0.15 corresponds to U = 43% (figure 2)

Thus, S1yr = (2.5in)(0.43) = 1.08 in.

In sandy soils, settlement occurs fast (soil is usually settled before construction is done) and the amount of settlement is determined in a different way than cohesive soils. The maximum settlement on dry sand can be calculated by

where smax is the maximum settlement (inches), q is the applied pressure (tsf), B is the width of the footing, and Nlowest is a number of

blows required to drive a rod while following a standard set of procedures. It should be noted that this equation has a correction factor if the groundwater table is close to the footing.

Example of a settlement analysis with a high water table and multiple soil layers

Time of Soil Settlement Animation Illustrates primary and secondary rates of consolidation.

Soil Compression Characteristics Animation Soil does not behave like a spring (i.e. it does not follow Hooke's Law). Once compressed it rebounds only slightly upon un-loading. This animation demonstrates the different behavior for normally consolidated and over-consolidated soil.

Settlement cracks that have developed in the masonry near the the Stout physics department offices in Jarvis Hall.

Same crack line but on the opposite side of the wall. The crack goes right into the floor tiling.

Differential settlement of the Soil Retaining wall at UW-Stout during the summer of 2001.

Stress and Settlement - Related Web Links

An Engineering Ethics Cases With Numerical Problems (an example with soils) from Texas A&M Geotechnical Engineering Hall of Fame (lots of famous people that developed the field of soil mechanics) Soil Testing Services and Suppliers Soil Settlement and Its Effect on Buildings Legal company that specializes in expansive soil claims Google - Search for

Foundations Foundations - Lecture Notes

"On account of the fact that there is no glory attached to the foundations and that the sources of success or failure are hidden deep in the ground, building foundations have always been treated as step children and their acts of revenge

for the lack of attention can be very embarrassing." Karl Terzaghi [source: Lundin, T., 2001, Are you saving nickels or dollars?, Hanson Insight newsletter, <http://www.hansonengineers.com/insight/0502/story4.htm>, May]

Important aspects to be aware of:

I. In the design plans, the depth of the footings should be indicated with respect to the final grade around the house. Foundation footings should be no less than 4 feet deep (Wisconsin Standard) and should not be placed onto disturbed soil. The footings need to be below the frost line. The frost line is the depth to which soil freezes during the winter. The soil above the frost line is subject to large amounts of fost heaving and shrinking (when ice melts) and can cause extreme cracking for too shallow of foundations.

II. Foundation footings should be placed upon good soil. This information can be obtained by soil exploration and laboratory testing. One could also ask neighbors about their foundations and the extent of cracking in their walls.

III. The sewer pipe should enter the house below the footing (sometimes at a depth of 8 inches from the bottom of the footing to the top of the pipe). The sewer pipe should have a slope of about 1/8in. every foot causing contents to move away from the house.

Bearing Capacity for Shallow Foundations

Structure foundations are subject not only to settlement but also to shear failures. First of all, foundations usually have the design of an inverted T. Where columns or walls are resting on a footing and the footing has an enlarged area to reduce the pressure exerted on the soil for a given load. In general, foundations must be designed to satisfy the following criteria:

1. They must be located properly (both vertically and horizontally orientation) so as not to be adversely affected by outside influences.

2. They must be safe from excessive (or non-uniform) settlement.3. They must be safe from bearing capacity failure (shear failure).

There are three modes of shear failure: general shear failure, local shear failure, and punching shear failure. These modes characterize the stress-strain dynamics that happen in certain soil types.

General shear failure is identified by a well-defined wedge beneath the foundation and slip surfaces extending diagonally from the side edges of the footing downward through the soil, then upward to the ground surface. The ground surface adjacent to the footing bulges upward. Soil displacement is accompanied by tilting of the foundation (unless the foundation is restrained). The load-settlement curve for the general shear case indicates that failure is abrupt.

Punching shear failure involves significant compression of a wedge-shaped soil zone beneath the foundation and is accompanied by the occurrence of vertical shear beneath the edges of the foundation. The soil zones beyond the edges of the foundation a little affected, and no significant degree of bulging occurs. Aside from a large settlement, failure is not clearly recognized.

Local shear failure has elements of both general and punching shear failure. It has well-defined slip surfaces that fade into the soil mass beyond the edges of the foundation and do not carry upward to the ground surface. Slight bulging of the ground surface adjacent to the foundation does occur. Significant vertical compression takes place beneath the foundation.

Terzaghi has developed a theory that predicts the ultimate bearing capacity a soil has in regards to shear failure. Before working with the formula’s, it is important to understand the terms "ultimate bearing capacity" (qult) and "allowable bearing capacity" (qa). The ultimate

bearing capacity of a soil refers to the loading per unit area that will just cause shear failure in the soil. Allowable bearing capacity refers to the loading per unit area that the soil is able to support without unsafe movement. Such that, (qult) = (safety factor)x(qa). The formulas

for calculating the qult are:

Continuous Footings (width B):

qult = cNc + γDfNq + 0.5γBNγ

Circular Footings (radius R):

qult = 1.2cNc + γDfNq + 0.6γRNγ

Square Footings (width B):

qult =1.2cNc + γDfNq + 0.4γBNγ

where qult = ultimate bearing capacity,

c = cohesion of soil (measured with a shearvane - as a rule of thumb, the unconfined compressive strength is about twice the cohesion of

the soil), γ = effective unit weight of soil, Df = depth of footing, or distance from ground surface to base of footing,

B = width of continuous or square footing, R = radius of circular footing, Nc, Nγ, Nq = soil-bearing capacity factors, dimensionless terms, whose values relate to the angle of internal friction, ϕ. These values can

be calculated when ϕ is known or they can be looked up in the table below.

Nq = eπtanϕtan2(45o + ϕ/2)

Nc = (Nq - 1)cot(ϕ) when ϕ > 0o or Nc =5.14 when ϕ = 0o.

Nγ = 2(Nq + 1)tanϕ

ϕ Nc Nq Nγ

0 5.14 1.0 0

5 6.5 1.6 0.5

10 8.3 2.5 1.2

15 14.0 3.9 2.6

20 14.8 6.4 5.4

25 20.7 10.7 10.8

30 30.1 18.4 22.4

32 35.5 23.2 30.2

34 42.2 29.4 41.1

36 50.6 37.7 56.3

38 61.4 48.9 78.0

40 75.3 64.2 109.4

42 93.7 85.4 155.6

44 118.4 115.3 224.6

46 152.1 158.5 330.4

48 199.3 222.3 496.0

50 266.9 319.1 762.9

As an example of using these equations, consider a strip of wall footing 3.5 ft wide and is being supported in a uniform deposit of stiff clay. The unconfined compressive strength (by a pocket penetrometer) of this soil is 2.8 kips/ft2 (1 kips = 1000 lbs). The unit weight is 130 lb/ft3. There was no groundwater encountered and the depth of the wall footing is 2 ft.

Find the ultimate bearing capacity of this footing and the allowable wall load, using a factor of safety of 3.

Solution:

qult = cNc + γDfNq + 0.5γBNγ

c~qu/2 = (2.8 kips/ft2)/2 = 1.4 kips/ft2

γ = 0.130 kips/ft3 Df = 2 ft

B = 3.5 ft from the table above: Nc = 14.0, Nq = 3.9, Nγ = 2.6

Thus, qult = (1.4 kips/ft2)(14) + (0.130 kips/ft3)(2 ft)(3.9) + (0.5)(0.130 kips/ft3)(3.5 ft)(2.6) = 21.2 kips/ft2

qa = qult/3 = (21.2 kips/ft2)/3 = 7.1 kips/ft2

The Terzaghi equations above do not consider eccentric (torques or non-vertical forces) loads, inclined foundation base, or footings on or near slopes. The bearing capacity of footings placed into sloping ground is less than if the footings were on level ground. In fact, the bearing capacity of a footing is inversely proportional to ground slope. Modifications to the Terzaghi equations do exist and enable one to calculate the ultimate bearing capacity under eccentric loads, inclined foundations, and sloped ground.

Foundations - Related Web Links

Septic Systems and Soil Failure Foundation Cracking Slide Show (Funded by FEMA) Google - Search for Soil Stress Google - Search for Soil Settlement

Pilings Pilings - Lecture Notes

During the 1950's, a large hotel was to be built along the coast in Florida. After performing soil explorations, the geotechnical engineers recommended 30 ft long friction piles to support a 25 story hotel. During the last drop of a pile driver's weight, one of the piles disappeared! It had suddenly busted through to a very weakly supporting soil layer called "Florida pancake" that was not identified in original explorations. The piles had to be lengthened to 140 ft. (Source: Why Buildings Fall Down, M. Levy and M. Salvadori, WW Norton & Company, 1992)

Pile and Caisson Foundations

When an extended layer of soil is unsuitable to build upon because of bearing capacity failure or excessive settlement, a Pile or Caisson foundation can be used to support structures. These foundations are designed to transmit the load of a structure to firmer soil, or rock that exists deep below the structure.

Pile foundations consists of a long and slender "member" that is forced or driven into the soil. It is driven until it rests on a hard, imprenetrable layer of soil or rock, the load of the structure is transmitted primarily axially through the pile. This type of pile is an end-bearing pile. If the pile cannot be driven to a hard stratum of soil or rock, the load of the structure must be borne primarily by skin friction or adhesion between the surface of the pile and adjacent soil. This is a friction pile. Piles can be made of timber, concrete (precast or cast-in-place), or steel (pipe-shaped or eye-beam shaped). Sometimes piles are a combination of these materials.

Caisson foundations usually consist of a structural box or chamber that is sunk in place or built in place by systematically excavating below the bottom of the unit, which thereby descends to the final depth. The drilled caisson is another type (less extensive in scope than the box type) that is constructed by using an auger drill to forma hole in the soil in which concrete is eventually poured.

Illustrations of different piling

I-Beam Piling Concrete Bulb Piling

Caisson (material removed from inside)

Larger Shaft Caisson For Performing Work Within the Caisson

Pile type

Description of use and availability

Range of Maximum Load (KN)

Timber Depends on wood (tree) type. Lengths in the 50 to 60 ft range (15 to 18 m) are usually available in most areas; lengths to about 75 ft (25 m) are available but in limited quantity; lengths up to the 100 ft range (30 m) are available, but supply is very limited.

100-300

Steel H and pipe Unlimited length; "short" sections are driven and additional sections are field-welded to obtain a desired total length.

Steel shell, cast-in-place Typically to between 100 and 125 ft (30 to 40 m), depending on shell type and manufacturer-contractor.

250- 700

Precast concrete Solid, small cross-section piles usually extend into the 50 – 60 ft length (15 to 18 m), depending on cross-section shape, dimensions, and manufacturer. Large-diameter cylinder piles can extend to about 200 ft long (60 m).

Drilled-shaft, cast-in-place concrete

Usually in the 50 – 70 ft range (15 to 25 m), depending on contractor equipment.

Bulb-type, cast-in-place concrete

Up to about 100 ft (30 m). 600-9000

Composite Related to available lengths of material in the different sections. If steel and thin-shell cast-in-place concrete are used, the length can be unlimited; if timber and thin-shell cast-in-place concrete are used, lengths can be on the order of 150 ft (45 m).

250- 600

Pilings - Related Web Links

Geopiers - New type of pier for intermediate soils Vibro-Pile, Co. (pictures of piling and pile testing) Timber Pilings Piling Rigs Sheet Piling Google - Search for Piling or Caissons Google - Search for Piling or Caissons Pictures

Review Quizzes Section 7

Review Quiz Section 7

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 8 Retaining Structures Jump to: Lecture Notes, Web Links

Earthwork Contracts Jump to: Lecture Notes, Web Links

Soil Reports Jump to: Lecture Notes, Web Links

Review Quizzes

Retaining Structures Retaining Structures - Lecture Notes

Retaining walls are usually built to hold back soil mass. However, retaining walls can also be constructed for aesthetic landscaping purposes.

Figure 1

There are three types of retaining walls: I. Simple Gravity Wall - These walls usually consist of large blocks of concrete or poured concrete. They are stabilized simply by the weight of the wall. II. Cantilever Wall - These walls are many times made of concrete. They use the weight of the backfill to help keep the wall stable. This type of wall is shown in the diagram above. It is important to build this type of wall strong enough to withstand substantial internal stresses where the stem and base are connected. III. Tie-back Wall - These walls can be composed of a variety of different materials (sheet piling is popular). They are stabilized by tying parts of the stem to a cable or metal rod. The cable or rod is then connected to an "anchor" that is buried deep and far back into the backfill. It is important to keep the anchor far enough away from the wall so that it is outside the radius of the most probable slip surface within the backfill. (Some walls can be combinations of these three types.)

Design of the wall needs to be made with the type of backfill in mind. Clayey soils are poor backfill material because of the large lateral pressures they may exert and the poor drainage characteristics. Many times, the backfill just to the right of the retaining wall (shown with dashed curves in the diagram above) consist of sand and gravel surrounding a drainage tile.

The design of the wall must:

1. Resist sliding along its base. 2. Resist overturning. 3. Not exceed the bearing capacity of the soil beneath the base. 4. Avoid excessive settlement. 5. Built structurally strong to resist failure from the build up of internal stresses produced by external forces. (But this is true for any structure!)

Well built wall near Jarvis Hall at UW-Stout.

(Click on the pictures to enlarge.)

Poorly built retaining wall on 21st Street in Menomonie, WI.

Poorly built soil retaining wall

Primer on Working With Distributed Loads

Consider the following example of a farm wagon loaded with corn.

Figure 2

To analyze the forces and pressures acting on the wagon, we need to first determine the pressures, P1 and P2.

P1 = γh = (7.4 kN/m3)(0.6m) = 4.44 kN/m2

Likewise, P2 = 7.4 kN/m2. Now, the pressure needs to be decomposed into a component that is uniform across the wagon bed and a

part that is changing with position.

Figure 3

The F/L vector in part (A) is calculated by

F/L = P1(length) = (4.44 kN/m2)(8 m) = 35.5 kN/m.

The number 35.5 kN/m represents the force per length (in and out of the paper) acting in the center of the wagon. The total force acting on the wagon, due to the uniform load, is

(F/L)(lengthin/out) = (35.5 kN/m)(6 m) = 213 kN.

Now, to calculate the F/L vector in part (B) of the diagram above:

F/L = (1/2) (P2-P1)(length) = (1/2)(7.4 kN/m2 - 4.44 kN/m2)(8 m) = 11.8 kN/m.

This number, 11.8 kN/m, represents the force per length (in and out of the paper) acting at a point 1/3 the distance from the high pressure side (or right side). Therefore, the total force acting on the wagon, due to the distributed load, is

(F/L)(lengthin/out) = (11.8 kN/m)(6 m) = 70.8 kN.

We are now left with the force diagram:

Figure 4

We have just determined the magnitude of the red vectors, now to determine the magnitude of the blue vectors (representing the wheels supporting the wagon), we need to apply the conditions for static equilibrium. First of all, the sum of all the forces must add to zero. Thus, 0 = F1+ F2 - F3 - F4. Secondly, the sum of all the torques (or moments) tending to twist the wagon bed about the

pivot point is also equal to zero. This second condition will enable us to determine one of the blue vectors (assuming clockwise to be positive):

0 = M1+M2-M3-M4 = F1(d) + F2(d) - F3(d) - F4(d)

0 = (F1)(8m-1m) + (F2)(0m) - (213 kN)(4m-0.5m) - (70.8 kN)(2.67m-0.5m)

Solving this equation, gives us F1 = 128 kN. Applying the first condition of equilibrium,

0 = F1+ F2 - F3 - F4 = 128 kN + F2 - 213 kN - 70.8 kN,

solving this equation gives us F2 = 155.8 kN. The problem is solved. A force of 128 kN is shared equally between the two front

tires (or 64 kN per tire) and a force of 155.8 kN is shared equally between the back tires (or 77.9 kN per tire).

So how is this related to the forces acting on a retaining wall? Just rotate the wagon bed 90o clockwise, and you'll pretty much have a situation that is very similar to the forces acting on a retaining wall.

In section 6 it was mentioned that the lateral pressure (or horizontal pressure) that develops within soil as a function of depth is about 1/2 the value of the vertical pressure, or PL=0.5PV. It is now time to "refine" this analysis by making the multiplication factor a

variable that is dependent upon the soil type. Such that, PL=Ko(PV), where Ko is defined as the coefficient of earth pressure at rest.

So what does earth pressure at rest mean? Earth pressure at rest refers to the lateral pressure caused by earth (or soil) that is prevented from lateral movement by an unyielding wall.

Representative Values of Ko

Soil Type Ko

Granular, loose 0.5-0.6

Granular, dense 0.3-0.5

Clay, soft 0.9-1.1 (undrained)

Clay, hard 0.8-0.9 (undrained)

Soil can exert active and passive pressures. To get an idea of what is meant by these two terms, consider a frictionless (between backfill and wall), infinitely rigid wall that is allowed to slide. The soil is allowed to expand in the lateral direction. Shearing resistance developed within the soil mass because of the soils shear strength acts opposite to the direction of the expansion. Thus, a soil's cohesion helps to reduce the lateral pressures applied to a wall that is allowed to move. There has been several theories put forth that takes into consideration active and passive earth pressures. In these cases, Ko becomes Ka and is now a function of the

angle of internal friction, cohesion, vertical pressure, and some geometrical parameters.

Examples of determining forces and pressures on some simple retaining walls

Some popular types of retaining walls

Gabion retaining walls consist of heavy gauge wire boxes that enclose large diameter rocks (the rocks are called rip-rap). The boxes are stacked and fastened together. This type of retaining wall is often used for erosion control and soil retainment along river banks. [Picture to the right is a gabion retaining wall built along the Snake River in Idaho. The wall has a hiking trail on top of it.]

(Click on picture to enlarge it.)

(A) Gabion stepped back, cantilever design

(B) Gabion stepped front, simple gravity design

Thinner retaining wall designs that usually consist of sheeting, piling, and/or planks. These often require tiebacks for stability.

Some typical tie-back designs:

Basic Anchoring System

Continuous Wall Anchor Spaced Piles as Anchors

Compression and Tension Piling

Tension Piles Used As Rakers

Sinking soil retaining wall built just East of Jarvis Hall here at UW-Stout. (pictures taken in June 2001)

Retaining Structures - Related Web Links

Hilfiker Retaining Walls Schnabel Foundation Company Rockwood (landscaping and soil retaining) Google - Search for Retaining Walls Google - Search for Retaining Walls Pictures

Earthwork Contracts Earthwork Contracts - Lecture Notes

Someone who desires something built or constructed is designated the owner. The owner may have consulted with architects, insurance companies, engineers, etc., before formulating any specific designs for a project. The owner will advertise for bids to complete the project. At this point in time, a contractor will put together a proposal to complete the project for a specified cost and submit it as a bid. Once a bid has been chosen, a contract will be written up and signed by both the owner and the contractor.

The relationship between parties involved with a construction project can be schematically illustrated as:

Model 1

In this model, the owner designs and finances the project. The contractor performs the necessary work to complete the project and the engineer works for the owner and oversees the work to ensure the project conforms to the specifications in the contract. The engineer and owner should speak as one voice when interacting with the contractor. The extent of direct interaction between the contractor and engineer may vary depending on the project. For smaller projects an engineer may not be involved.

Another model that describes the parties involved in a project may include a construction manager. This is shown below.

Model 2

This model is very similar to model 1. The construction manager works very closely with the owner, contractor and sub-contractors. They observe the work in progress and manage the materials needed and the contractors involved. In this model, the manager is usually employed by the owner and does not work directly for the contractors.

Contract

Legal aspects of contracts is a bit beyond the scope of this course. But it is important to introduce you to the general content of a contract that you may encounter when the project involves earthwork or excavating. Within such a contract, there should be a section with the heading Earthwork. This section will include

A. Scope B. Materials C. Workmanship (or Quality/Tolerance of work) D. Payment

Scope describes the project and the work needing to be accomplished. It is a general overview of the earthwork needed.

The Materials are usually categorized as either classified or unclassified. If a material is classified it must conform to a certain specification. An example of this would be when a coarse grained (according to USCS classification) soil is needed for fill-dirt This section may include statements requiring you to perform testing, or submit samples for testing, to confirm that the classified material meets specifications. Soil at the project site or excavated soil at the site should be used as construction material whenever possible to reduce the need of bringing in fill from elsewhere. Workmanship may involve considerations for blocking traffic (autos, boats, etc.), interrupting water flow or drainage, specific sloping may be needed, etc. This section is just a description of how closely you need to follow design plans and what latitude exist for accomplishing the task in a different way. Payment for earthwork is usually put forth as a cost per volume of obtaining, moving, and placing (or removal of waste material from the site) both classified or unclassified material. This part may also contain statements regarding who pays for down time. This is the time in which equipment or laborers cannot perform the work because of weather, non-arrival of materials, etc.

Most contracts will contain statements about the subsurface conditions and require the contractor to indicate that they have carefully examined this information, are aware of the conditions that may affect their work, and can perform the work for the bid price. The contract may have extensive information about the subsurface or possiblly little to no information. Before signing such a contract, the bidder may need to perform (or request) more subsurface information to be confident about how much work is required. Most statements, like the ones described above, are in a contract to protect the owner against frivolous or unwarranted extra costs that the contractor may require for completing the project.

On occasion, a contractor may encounter a situation that was unpredictable (by most reasonable standards) and requires additional work and expenses. At this point, the owner and contractor need to discuss this unforeseen situation and come to an agreement on payment for expenses and work. Most disputes that arise between a contractor and owner after the project is begun can be worked out by mutual agreement. In some disputes, the possibility of needing a third party mediator is warranted. The last step in resolving contract disputes involves filing legal claims and pursuing it through the legal system.

Earthwork Contracts - Related Web Links

Google - Search for Earthwork Contracts

Soil Reports Soil Reports - Lecture Notes

"Owner's sometimes forego borings (to save money) and then ask you to make recommendations. This is like asking a medical doctor to make a diagnosis but not allowing the doctor to perform tests." Bill Kwazny, P.E.

Soil reports are documents that contain information about the subsurface structure and composition. Some reports are quite brief and only contain a limited amount of information. Other reports can be quite elaborate with thousands (maybe millions) of dollars spent to examine the subsurface structure and provide recommendations on how this examination will affect the project being proposed. Sometimes the project may need modified due to subsurface considerations. The most important reason for examining the subsurface is to ensure the structure's foundation will be sufficiently supported. This means the subsurface must have sufficient bearing capacity and will not be subjected to unacceptable settling characteristics. Other reasons might include subgrade working conditions, dewatering, making sure nearby structures are not adversely affected by excavating, geological stability (earthquakes, mass movements, etc.), cost of excavating - digging into solid rock may require a special plan, shoring or sloping considerations, etc.

For massive structures such as suspension bridges and multi-story buildings, a detailed soil engineering report will be financed. These reports usually contain:

1. Scope and Purpose 2. Introduction 3. Geological Setting 4. Field Studies Performed 5. Laboratory Tests Performed

6. Analysis 7. Conclusions and Recommendations (Including an appendix for a more detailed look at the numbers obtained in the tests.)

The smaller soil reports might only contain information about the water table and a qualititative measure of soil type as a function of depth (such as a SPT) for a limited number sampling positions on a grid.

Two popular soil tests that are often found on reports include the Standard Penetration Test (SPT) and/or the Cone Penetration Test (CPT).

Standard Penetration Test is widely used in the U.S. It is inexpensive, can be quickly performed, and is simple. It consists of a hardened steel, split spoon sampler that is attached to the end of a drilling rod and driven into the ground.

Split spoon sampler for the Standard Penetration Test

This device must conform to a standardized geometric design. It is driven into the ground with a drop hammer that weighs 140 lb and falls 30 in for every hammering. When it is driven 18 in into the ground, the standard penetration resistance (N-value) is the number of blows to move the last 12 in. This device can obtain a sample of the soil as a function of depth. A soil type boundary is encountered when the corrected N-value significantly changes at a particular depth. The N-value as a function of depth needs to be corrected due to overburden pressure. This means that even if the soil type does not change as a function of depth, the non-corrected N-value will gradually go up because of the overburden pressure. And the corrected N-value should remain constant as a function of depth if the soil type does not change.

Mathematical corrections needed:

Ncorrected = CNNmeasured

where CN is the correction factor with the values

CN = 0.77Log10(20/p), if p < 0.25 tsf

or

CN = 0.77Log10(19.5/p), if p > 0.25 tsf.

The p quantity represents the overburden pressure at that depth.

Workers are marking off a split-spoon sampler to determine N-values as a function of depth. This work was being done just North of the Menomonie public library.

Contents of the split-spoon sampler are being extracted, marked, and bagged for laboratory analysis.

The Cone Penetration Test is widely used in Europe and is gaining in popularity in the U.S. It consists of a cone and a friction sleeve that has a standard geometric design as shown below.

Cone and friction sleeve for the Cone Penetration Test

The CPT measures (i) cone resistance, and (ii) cone plus sleeve resistance. One can then mathematically solve for the sleeve resistance by the equation Ffriction = Ftotal - Fcone, where F represents a corrected N-value. The data from this test is usually

presented as cone resistance, friction resistance, and friction ratio. The friction ratio is defined as (Ffriction/Fcone). As a general rule,

the friction ratio is larger in cohesive soils than in cohesionless soils.

The CPT can be further divided into a Static Cone Test (or Dutch Cone Test) which uses a hydraulic device to drive the cone into the ground. This device is capable of measuring the resistance encountered as a function of depth. The Dynamic Cone Test (another CPT) drives the cone into the ground with a hammer.

Example soil report

Standards For Geotechnical And Engineering Geology Reports by J. David Rogers, Ph.D., R.G., C.E.G. This is a nice web document describing the proper contents of a geotechnical report.

Table of Standardized Tests and Procedures

Property of Soil Type of Test ASTM Designation AASHTO Designation

LABORATORY TESTING OF SOILS

Grain-size distribution

Mechanical analysis D421, D422, D1140 T88

Consistency Liquid limit (LL) D4318 T89

Plastic limit (PL) D4318 T90

Plasticity index (PI) D4318 T90

Unit weight Specific gravity D854 T100

Moisture Natural water content

Field moisture equivalent

D2216 T93

Centrifuge moisture equivalent

D425

Shear Strength Unconfined compression

D2166 T208

Direct shear D3080 T236

Triaxial D2850 T234

Volume change Shrinkage factors D427 T92

Compressibility Consolidation D2435 T216

Permeability Permeability D2434 T215

Compaction characteristics

Standard proctor D698 T99

Modified proctor D1557 T180

California bearing ratio (CBR)

D1883 T193

FIELD TESTING OF SOILS

Compaction control Moisture-density relations

D698 T99, T180

In-place density D1556, D2167 T191, T205

Shear strength(soft clay)

Vane test D2573 T223

Relative density (granular soil)

Penetration test D1586 T206

Permeability Pumping test

Bearing capacity

Pavements CBR

Plate bearing D1195, D1196 T221, T222

Footings Plate bearing D1194 T235

Piles (vertical load) Load test D1143

Soil Reports - Related Web Links

Space Penetrometry - The application of penetrometry - defined here as the measurement of a body's penetration (e.g. force, deceleration, velocity, depth) to derive mechanical and/or structural information concerning the target. Cone Penetration Test (mainly related to earthquake liquefaction) Soil Mechanics Software and Example Boring Log Swedish Geotechnical Society Report on Using the CPT Tools catalog from Geoprobe Systems Google - Search for Soil Reports Google - Search for Standard Penetration Test Google - Search for Cone Penetration Test

Review Quizzes Section 8

Review Quiz Section 8

"Knowing the forces that shape the Earth, allows you to better control and utilize the 'forces' that affect construction and building."

Dr. Alan Scott - Your Instructor

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 9 Glaciers Jump to: Lecture Notes, Web Links

Shorelines Jump to: Lecture Notes, Web Links

Review Quizzes

Glaciers Glaciers - Lecture Notes

Penguins frequent the antarctic continental glacier in the South polar region.

What is a glacier and why are they important?

A glacier has the following characteristics: 1. It is a large mass of ice. 2. It forms in geographical region where the amount (in terms of mass) of snowfall per year exceeds the amount of ice that melts per year. 3. It is capable of flowing downhill. The rate of flow is about 2 meters per day but this rate varies considerably depending on many factors. Ice that is subjected to high pressure is capable of a "plastic" type of flow. (When you bend a paper clip, the metal tends to bend in a "plastic" way.) 4. It has a huge influence on shaping the land via a special type of erosion and deposition.

There exists two types of glaciers: Valley Glaciers and Continental Glaciers. Valley Glaciers form in mountainous regions and are sometimes called alpine glaciers. They flow downhill following mountain valleys. The other type is called a Continental Glacier. Continental glaciers are usually much larger and more slowly moving than valley glaciers. These glaciers can cover most of a continent. Two very large continental glaciers are the Greenland and Antarctica glaciers (sometimes called ice sheets).

MacMurdo Station, Southern most point attainable by

sea.

Ross Ice Shelf (or Sheet)

Picture of Mt. Rainier in Washington state.

There are 25 different alpine glaciers on the side of this mountain. It is the largest system of glaciers outside of Alaska in the United States. (Short PowerPoint presentation on Mt. Rainier glaciers.)

It is important because about 10% of Earth's land surface is covered with glacial ice. Studying the gas that is trapped within glacial ice provides information about the earth's climatic past. (The layers of ice are very analagous to tree rings in regards to what they can tell us about the earth's past.) Studying the rate at which glaciers are melting or advancing are a good indicator of possible global climate changes such as global warming. Glaciers are also responsible for creating much of the landforms we have Wisconsin.

Terminology Describing a Glacier

Ablation is the general process by which a glacier loses ice mass either by melting, breaking apart, sublimation, or even wind eroson. Accumulation refers to the amount of snow added to the glacier (usually per year). The snowline separates the zones of accumulation (more snow accumulating than melting) and the zone of ablation (more snow melting than accumulating). The balance between accumulating snow and melting snow is often refered to as the glacial budget. The zone of fracture describes the top portion of the glacier and is composed of ice that is brittle or not capable of flowing. This ice rides "piggy-back" on top of deeper ice. Crevasses (sometimes large and deep) often form in this portion of the glacier. (A good analogy of this behavior is a Snickers candy bar. Unwrap a new Snickers candy bar and bend it from the ends. The chocolate coating opens up with "crevasses" and the carmel inside closely represents the

deeper, plastic flowing ice.) Calving is the process by which a large portion of the glacier breaks off and drops into an ocean or lake. Thus, creating an iceberg.

Fig. 1

Terminology Describing Landforms Created by Glaciers

In moutainous regions, a "U" shaped valley can be formed in a valley by plucking (i.e. to pick up and move) and scraping the sides creating a glacial trough. Valley glaciers commonly form cirques near their high elevation regions. These cirques are bowl shaped depressions that are open on the downhill side. Sharp-edged mountainous ridges and peaks formed by glacials are called aretes and horns, respectively. Fjords are often formed at the end of glacier formed valleys.

Yosemite National Park (click to enlarge)

Yosemite was carved out by glaciers. The valley is clearly "U" shaped.

A water-fall in the steep sides of Yosemite Valley.

(click to enlarge)

The material that gets deposited out of a glacier as it melts and/or retreats is called glacial drift. The subsurface below much of Western Wisconsin has a 50-60 foot thick layer of glacial drift. If a glacier advances, stops, and then retreats, an end moraine is a landform built-up by the glacier depositing its load in the region where it stopped. The deposition created by the furthest advance of the glacier is called the terminal moraine. The Southwest area of Wisconsin has a unique "island" containing no glacial drift called the driftless region.

Ice Ages and Historical Glaciation

The earth has experienced numerous periods of global cooling and warming. The duration and intensity (degree of cooling and warming) of each period varies. As a period of cooling occurs, glaciers advance and the sea level falls. When warming occurs, the glaciers retreat and the sea level increases.

There exists some evidence that most of the earth's surface was once (maybe several times) covered with ice. This comes from studying the isotopic ratio of carbon 12 and carbon 13 found in ocean floor sediments. This ratio can be related to the average climatic temperature. These measurements suggests a global ice age (or a "snowball earth") happened around 570-700 million years ago and several episodes of glaciation have happened in more recent times (~1 million years ago).

The most recent period of extensive glaciation peaked about 18,000 years ago. Surprisingly, the average global temperature does not need to change significantly for there to be a period of large-scale glaciation. Only about 5oC change is necessary.

The Pleistocene Epoch (about 1 million years ago) of Geologic Time has been called the "Ice Age". About 20 cycles of warming and cooling occurred during this epoch. However, periods of glaciation have happened during other epochs (or periods) of geologic time.

Artist's depiction of how the landscape looked during the ice ages with a glacier in the background and a Wooly Mammoth in the foreground. Drawing courtesy of the Wisconsin Ice Age state park.

Local Glacial Geology

Interstate State Park in Minnesota has some interesting glacial potholes that have been weathered into local rock formations. About 10,000 years ago retreating glaciers and their outwash carved formations within igneous rock strata. This igneous rock strata formed from lava flows about 1.1 billion years ago.

Picture looking down upon some of the rock formations at Interstate State Park in MN.

A glacial pothole with two small kids standing in it. This picture is also from Interstate State Park in MN. The St.

Croix river can be seen in the upper right of the picture.

Chippewa Moraine Ice Age Scientific Reserve near New Auburn, WI. Concentration of glacial lakes and landforms about 60 miles Northeast of Menomonie.

Mill Bluff and the great Wisconsin Glacial Lake (click to enlarge picture)

Northeast view on top of Mill Bluff. Interstate 94 runs North and South and can be seen in the bottom of the picture.

An area of about 1,825 square miles was covered with water in Wisconsin's central region due to glaciation about 70,000 years ago. Water depths reached 150 feet. The bluffs are composed of sandstone mounds of Cambrian-Ordovician time. These bluffs were islands in the Wisconsin Glacial Lake.

The picture to the left was taken when my son and I went on a geological expedition to find remnants of the Great Wisconsin Glacial Lake at the end of the summer of 2001.

Why Does the Earth Experience Periods of Warming Or Cooling?

Theories presented to explain periods of glaciation: 1. Variations in the Earth's orbit and inclination to the Sun. 2. Plate tectonics and the changing position of continents. 3. Changes in the atmosphere. For example, if a sufficient number of volcanoes erupted in a short period of time, the amount of sun light penetrating the atmosphere may decrease from volcanic dust and ash in the upper atmosphere. 4. Changes in sea water circulation.

Theories 1 and 2 above, seem to hold the most promise and are often cited in explaining the periods of glaciation.

A detailed calculation (using the laws of physics) shows that the Earth undergoes slight variations in its motion with respect to the Sun. This causes differing amounts of sun light to fall on different locations at different times on the Earth. [Credit for the first such analysis is usually given to Milutin Milankovitch, a Yugoslavian scientist.]

I. Eccentricity - One variation is that the Earth is sometimes closer to the Sun than at other times. This happens on cycles of about 100,000 years in duration. II. Precession - The Earth behaves like a top that is spinning and placed at an angle onto a table. Instead of falling over, the top rotates around a vertical line. This happens in cycles about every 26,000 years. III. Nutation - In addition to precessing about a vertical axis, the earth also wobbles (to a very small degree). A wobble which is described as a change in the angle to which the spin axis makes with respect to the orbital plane.

fig. 2

In a related issue, the amount of CO2 in our atmosphere has been rising. Most scientist now believe that this (together

with other possible greenhouse gases) are causing the global temperature to increase in what is called the "Greenhouse Effect". In essence, this increase in temperature causes a retreat of glaciers around the world and an increase in sea level. Here is a good link containing information about Ice Ages and the Greenhouse Effect.

Glaciers - Related Web Links

Mendenhall Glacier in Alaska (PowerPoint), by Nancy Novotney (Geology student at UW-Stout in 2005.)

Svartisen Subglacial Laboratory - A scientific research laboratory located beneath 700 feet of ice. ICE and Glacier web sites about glaciers from Rice University National Snow and Ice Data Center (NSIDC), all about glaciers Animated Glacier Fly-bys, a NASA web site Regional Landscape Ecosystems of Michigan, Minnesota, and Wisconsin: A Working Map and Classification, A web site of the USGS. Course on Glacial Geology Pictures (1,2) of glaciers from Duke University Slide Show on glaciers, by Sharon L. Gabel, SUNY at Oswego

Ice Age Park & Trail in Wisconsin, Ice Age Trail Landscape Discussion of Wisconsin's Glacial Landscape Geographical Provinces of Wisconsin (a lot of geological information) Google - Search for Glaciers Google - Search for Wisconsin Glaciers Google - Search for Valley Glaciers or Continental Glaciers

Shorelines Shorelines - Lecture Notes

"Drifting on the whims of sand and sea, barrier islands by the hundreds rim our Atlantic and Gulf coasts, buffering the mainland from storms and offering beach lovers a glimpse of paradise. Yet these delicate strands are often asked to do more: to anchor homes and hotels, lighthouses and lifestyles -- in short, to hold still. It's against their nature."

Jennifer Ackerman, "Islands at the Edge"

Shorelines are very dynamic places. The major influences include erosion, deposition, water waves, and tides. What is presented below can be considered the "steady state" characteristics. Of course, this steady state can be greatly disrupted (temporarily) by an encroaching hurricane or other more infrequent phenomena.

Waves

Waves are generated mostly by the wind. (If one observes a lake on a windy day, the largest waves on the lake are downwind.) The water molecules don't travel along the wave like a surfer using a surf board. What does travel along the wave is energy. This wave energy is mostly confined to the top portion of the water. When waves reach the shore, the tops of the waves usually "topple" forming breakers. The region where breakers usually form is called the surf zone.

Surf zone along the Pacific Ocean. This site is near Long

Beach, Washington.

Waves along the Northern shoreline of Lake Menomin on a

windy day. Click on the picture to see a more detailed

description.

fig. 3

The waves usually approach the coastline at a slight angle. These waves experience refraction as they approach. Such that, the shallower the water, the slower the waves will travel. This process is shown in figure 3 above where the wave fronts are slowing down surrounding the light-house headland.

Click on the picture to enlarge.

Water currents and sediment transport effect one another on a beach. Longshore current and longshore drift - Since the waves approach the coast at an angle a current develops which moves parallel to the shore. Beach sediments move along with this current. Rip currents - Narrow, deep currents can form in the surf zone and are directed out to sea. They develop in the surf where the bottom forms small channels. These currents can also be found along side artificials structures that shoot out into the surf such as piers. Swimmers can sometimes get caught in rip currents and pushed out to sea. The longshore drift will form baymouth bars and spits when they encounter an estuary (a funnel shaped inlet into the sea). The longshore drift continues to deposit sediments parallel to the shoreline even when estuaries are encountered. Barrier Islands - Long sandbar that builds up from longshore drift. These sandbars are usually separated from the coast by tidal flats or shallow lagoons. Some common barrier islands include Cape Hatteras and Padre Island off the coast of

Texas.

Illustrations of Rip Currents

Signs at Whitefish Dunes State Park in Wisconsin warn swimmers of a dangerous rip current (or sometimes called an undertow).

The picture to the left shows a rip current area at low tide. The water in the foreground is rushing preferentially out to sea at this spot. The water is moving left to right. The location and size of sand bars create this current of water. (The picture is on the Pacific coast near Long Beach, WA.)

Interactive map showing parts of a beach

Artificial Structures

For many reasons, people have built structures along shorelines to influence sedimentation or erosion. The processes that add or subtract sediments to the shore are related to the sand budget of the beach.

Sedimentation Processes

Waves eroding the backshore cliffs or rock Longshore drift

River loads being dropped at the mouth of river

Erosional Processes

Offshore winds blowing sand in-land Longshore drift (note: can be erosional or depositional)

Tidal currents, rip currents, waves

Structures built to change the sedimentation or erosional processes: 1. Groins - (shown in figure 3) Barrier built perpendicular to the shore. It is designed to capture more sediments for a particular part of the shore. In figure 3, House A is getting more beach by building a groin which ultimately takes beach sediments away from House B. 2. Jetties - Very similar to groins but are usually designed to protect inlets (for marina boat traffic) from excessive sedimentation.

Click on the picture to enlarge.

3. Breakwater - Large barrier built parallel to the shore. Designed to protect boats from large waves. In essence, breakwater creates a semi-quiet marina along the shore. These are sometimes physically connected to the shore for construction purposes.

An artificial breakwall (or breakwater) built to protect a harbor and the Trump Casino boat in Gary, IN. Photo is courtesy of Craig Wenner, former student in the Geology and Soil Mechanics course. Craig's company Rocks and Docks (email: rocks@Lakefield.net) was involved in the breakwall construction project. The project involved quarrying the stone, transporting it, and placement. A miniature model of the harbor was built to examine the effectiveness of the breakwater prior to construction.

Development on Shoreline Areas

Many beach areas are popular spots on which to build homes or hotels. But the beach is a dynamic system that is in

continuous change. Some changes can be dramatic as when a hurricane makes landfall. The combinations of high tide and sea surge (in-coming part of the rotating hurricane), can cause the sand on the beach to shift dramatically. Millions of dollars of taxpayer's money are spent annually to rebuild eroded shorelines and rebuild weakened structures built on the shifting sand. Many believe it is foolish to interfere with the natural processes effecting the beach and present the notion that "The best way to save a beach is to leave it alone." The debate of whether to develop or not is strikingly similar to the issue of building in a floodplain of a river. How many times is one willing to put money into maintenance and repair? It would be a non-issue if taxpayer money was not involved.

Tides

The water level along coastlines rise and fall twice each 24 hour period. This cyclic behavior is referred to as tides. It is the result of the gravitational influence of the Moon and the Sun on the Earth's oceans. The magnitude of the high tides and low tides depends on your (1) geographical location and (2) the alignment of the Earth, Moon, and Sun. This influence can be illustrated (see below) with gravitational force vectors acting upon the ocean.

Take all the black vectors and subtract the average force shown in red. This results in the following "effective" force (shown in grey vectors below) acting upon the oceans.

I have also developed an animation of tides.

The largest amount of swing in high and low tide is called the Spring Tide. It results when the Earth-Moon-Sun are aligned adding to the gravitational effect. A Neap Tide occurs when the Moon-Earth-Sun form a 90o angle and the gravitational force is partially cancelled out. Disastrous flooding can occur for a location along the coast that experiences a high tide combined with the landfall of a hurricane, simultaneously.

The constant rise and fall of water does have a very small effect on the Earth's rotation. It causes the Earth's rotation to slow thus increasing the time required for one rotation (such that, one day). About 570 million years ago the Earth rotated once every 21 hours. Gravitational tidal effects - of the Earth acting upon the Moon - have also caused the Moon to always have the same side facing the Earth.

Shorelines - Related Web Links

Coastal Geology by the National Park Service Waves from the Grand Valley State University, Department of Geology Barrier Islands of the United States Atlantic and Gulf Coasts Pictures of Beach Processes and Barrier Islands Coastlines of Atlantic Canada (Excellent web site with pictures of shorelines.) Shore Protection Projects in New Jersey Cape Hatteras Lighthouse home page Shoreline lecture notes from Dr. Terry Engelder, Penn State Google - Search for Shoreline Geology Google - Search for Tides, Geology

Review Quizzes Section 9

Review Quiz Section 9 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapter Glaciers, Shorelines, The Ocean Floor)

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

Section 10 Deserts and Wind Jump to: Lecture Notes, Web Links

Planetary Geology Jump to: Lecture Notes, Web Links

Review Quizzes

Deserts and Wind Deserts and Wind - Lecture Notes

What is a desert?

A desert is a geographical location where there is less than 25 cm (10 inches) of precipitation per year. The average annual precipitation in Menomonie, WI, is about 31 inches. The cause of this low rainfall may be the result of many influences. These influences include: 1. Global Air Circulation - At about +/- 30o latitude, a high pressure of dry air moving downwards inhibits cloud formation. (See figures 13.2 and 13.3 in Tarbuck and Lutgens.) The Sahara Desert is largely governed by this effect and a great distance from the ocean. 2. Rain Shadow effect - As prevailing winds approach large mountain ranges, the air is forced to rise and cool. This produces an abundance of cloud formation and high precipitation. After having moved over the mountain range, the air has lost most of its moisture. It also descends and warms which prevents cloud formation. The Sierra Nevada mountain range in California produces large regions of dry land East of the range in Nevada and Arizona.

Composite of three pictures showing the rain shadow effect. Prevailing winds are moving from right to left and

are going over the cascade mountains of the Pacific Northwest (US). The clouds are seen in the right but not the left. This picture was taken aboard a commercial airliner at an altitude of about 30,000 feet above Washington state

looking South. The mountain in the background is Mt. Rainier.

3. Distance from Large Water Body - As a general rule, the farther the air has to travel, the more likely it will have already lost its moisture. 4. Proximity to Cold Ocean Currents - Cold moist air moving onto land will many times warm up and make rainfall less likely.

Important Meteorological Information

When we refer to the weather as being dry or humid, we are referring to the amount of water vapor present in the air. If the water vapor content reaches saturation, water vapor condenses out of the air and forms tiny, liquid droplets of water (such that, a fog or a cloud is formed). The Relative Humidity is defined as the ratio of the amount of water vapor present divided by the amount of water vapor needed for saturation, such that:

(Relative Humidity) = ((amount of water vapor present)/(amount needed for saturation at that temperature) ) x 100%.

In general, warmer air can contain more water vapor than cooler air before reaching saturation. When air is cooled it reaches a point where the amount of water vapor present is equal to the amount needed for saturation. The temperature required to reach this point of 100% relative humidity is called the Dew Point. When warm air is cooled, the water vapor condenses out and forms clouds which result in precipitation. When cool air is warmed, liquid water droplets evaporate into water vapor. Thus preventing any cloud formation or precipitation from falling.

Cloud Chamber Video - This video shows clouds being formed from alcohol vapor above dry ice. I (Dr. Scott) made the cloud chamber during the fall semester of '01. One can also see "whispy condensation tracks" formed in the wake of charged particles moving through the chamber. I placed two radioactive objects into the chamber to watch these tracks. You can see them by looking carefully. Cosmic rays will also produce tracks that can be seen in the chamber.

Common Misconceptions About Deserts Deserts are always hot and dry. Deserts are dry (on average) but they may not be hot. The Gobi Desert in Mongolia has an average high temperature of -19oC (note: 0oC is freezing). One of the earth's most unique deserts is Taylor Valley in Antarctica.

Deserts are mostly shaped by the wind. Yes there is wind and it does some shaping of the land but the predominant influence that shapes landforms is water. When water comes to a desert, a large proportion of it forms runoff and erodes the land.

Deserts are lifeless, barren wastelands. The amount of biological activity is significantly less than in a tropical rainforest, but it does have a significant amount of animal and plant life that has

adapted to the dry environment. Aesthetically, deserts can be quite beautiful - consider the Painted Desert in the American Southwest. One creature that has adapted well to sandy, desert-like environments is the antlion.

Antlion

Mechanical weathering is a predominant influence in a desert. Thus, larger rocks are constantly being made into smaller rocks by means of abrasion, falls, freeze/thaw, etc. The soils are usually pedacols and in many cases are immature and transported. Most deserts are rocky or covered with "desert pavement". Sand dunes are not the predominant landforms in most deserts! In fact, only 1/5 of the desert areas in the world are covered with sand dunes. About 1/10 of the Sahara Desert is covered with sand.

Deserts are prone to flash flooding. The sparse rain that does come, usually takes the form of a short duration, heavy down-pour. "Rivers" in desert regions are usually dry and are called Dry Washes. The water that enters dry washes evaporates and infiltrates fast, causes a significant amount of erosion when flowing, and most die-out before reaching a larger river that would eventually flow into the ocean. The rivers are said to be "ephemeral".

Wind Erosion and Landforms

Desert pavement is created by wind erosion through a process called deflation. This process is characterized by small grain particles getting eroded away by the wind leaving coarse gravel/stones. The resulting land surface is lowered.

Mesas - Many desert terrains contain landforms that were created from horizontal rock layers getting eroded away around the base of a flat, weathering resistant rock layer. These mesas look like hills with flat "tops".

Sand Dunes

Sandy landforms that are produced predominantly by wind are called sand dunes. They need (1) arid conditions to thrive (and move), (2) good supply of sand from surrounding weathered rock, and (3) a an environment frequented by winds. The shape is governed by laminar and turbulent fluid flow (i.e. air as a fluid) around obstacles and this flow's ability to move the sand particles. [Sand drifts are usually the beginnings of sand dunes.] Small perturbation in the laminar flow is what initiates sand drifts, then the drifts themselves become the obstacle.

As a general rule, the gently sloping side of the dune faces into the prevailing wind direction. The entire sand dune moves downwind slowly as a result of erosion happening on the side facing the wind and deposition happening on the downwind side.

Types of Sand Dunes: 1. Barchan dunes - These are crescent shaped dunes with the points directed downwind. Produced by constant wind direction. 2. Transverse dunes - Dunes that form long ridges that are perpendicular to the direction of the wind. Sometimes the transverse and barchan dunes can combine to form barchanoid dunes. Usually occur where the sand supply is abundant. 3. Blowout (or parabolic) dunes - Crescent shaped dunes with points toward the wind (i.e. opposite to the Barchan dune). Usually associated with deflation on the interior of the crescent. 4. Longitudinal dunes - Dunes that form long ridges of sand oriented parallel to the prevailing wind direction. Usually occur where the sand supply is limited. 5. Star dunes - Resembles a star shape and is produced by shifting winds.

Much of the soils in the midwest can be characterized as wind blown silt from glacial debris called loess.

Deserts and the Global Perspective

In many parts of the world, in particular - Northern Africa, a process called desertification is at work. The regions that surround deserts can be very sensitive to human intervention. These semi-arid lands usually support a significant amount of vegetation. However, a problem develops if there is a period of extended drought-like conditions which is compounded by a rapid exploitation of the land for farming. This combination reduces the amount of native vegetation, kills the planted crops, and the land is subsequently exposed to intense erosion. This region progresses into a more desert-like environment. This further exhacerbates the human conditions in the area - more starvation/malnutrition and a lessened soil quality for producing crops. Population increases further complicates the problem in these areas. Some scientist estimate that about 35% of the Earth's surface is potentially threatened by desertification. [Source of much of this information: F. Press, R. Siever, Understanding Earth, 2nd Ed. (1994), p. 362] Aral Sea is a prime example of how human influence has adversely impacted the ecology of a region.

The great Dust Bowl of the 1930's.

Deserts and Wind - Related Web Links

Wind Erosion Research Unit (Kansas State University) - lots of pictures of wind erosion, on-line movies of the dust bowl and dune evolution within a wind tunnel. Death Valley National Park Mohave Desert (Mohave National Preserve) Links to Desert Information and Tourism Glossary of desert and geological terms Pictures (1,2) of desert landforms

Lecture Outline of deserts and landforms, W.K. Fletcher, University of British Columbia Precipitation Map of the US Google - Search for Deserts, Geology Google - Search for Sand Dunes Google - Search for Desert Landforms

Planetary Geology Planetary Geology - Lecture Notes

The general approach to science is to ask what do we know and how do we know it? In presenting the topic of planetary geology I would like to reverse this process and first present the "modes" to which observations were made. Then proceed to discuss how these observations have formed the basis for our view of the geology of these distant celestial objects.

How can we learn about distant worlds? Such that, how can we measure the characteristics of celestial objects and/or planets?

Method #1: Spectroscopic Analysis - Visible light that our eyes respond to is only a small part of what is called the Electromagnetic Spectrum. Every object in the universe (including ourselves) emit, absorb, and reflect light in a specific way. By analyzing the light spectrum that is coming from distant objects in the universe, we can examine the chemical composition and the motion of that object. Spectroscopic analysis is a very powerful tool in science. Emission and Absorption Spectra of the chemical elements.

Method #2: Optical Imaging (visible and non-visible light) - Telescopes can use mirrors and lenses to create an image of a distant object. These images can give us information about the structure, position, and motion of distant objects. [Optical imaging is sometimes combined with spectroscopic analysis instruments.] These instruments may use visible light but can also image non-visible light that is being emitted from an object. Here is a nice web page that presents the different types of telescopes. The Hubble Space Telescope is one of the most prominent telescopes.

Method #3: Space Probes (with numerous measuring capabilities) - Space probes have the advantage of actually going to the distant celestial object and orbit near it and/or land onto it. Some landing probes can take direct measurements of the planet's surface geology. Things that space probes can measure include: biological activity, spectroscopic analysis, magnetic field, charged particles, optical imaging (sometimes 3-D), temperature, pressure, soil conditions.

Space Probe (most recent to older)

Journey

Cassini Titan - a moon of Saturn (Arrival date 2004)

STARDUST Launched in Feb. '99, Intended to fly into Comet Wild-2's tail to collect cometary dust in early 2004.

Mars Exploration Rovers

Two rover missions launched in 2003 toward Mars. Landing is expected January 3 and 24, 2004. Rover's can travel far and contain spectroscopic tools, cameras, microscopes, and a rock abrasion tool. The rover's are named Spirit and Opportunity.

Mars Express

This mission contains an orbiter and lander called Beagle II. The lander will touch down on December 25, 2003. Contains a mass spectrometer (can radiometrically date the rocks), cameras, microscope, wind, pressure, temperature, and a mole-like device for probing the soil. (A mission by the European Space Agency.)

Nozomi A Japanese space probe intended for Mars. It was damaged by a Solar Flare. It is not expected to complete its mission.

Mars Polar Lander

Believed to have crashed onto the planets surface due to a mis-understanding between English and Metric units. Mission lost. (Dec. '99)

Mars OdysseyLaunched in 2001. Reached Mars in the same year of 2001. The instruments include a high resolution camera and spectroscopic instruments.

Mars Global Surveyor

Launched Nov. '96, started optically mapping the surface of Mars in April '99. Highest resolution is 1.4 m/pixel.

Galileo Jupiter and Jupiter's Moon (arrived in 1995)

NEAR Swing by a near earth asteroid named Eros (Feb. '99)

Pathfinder Orbiter, lander, and rover on Mars (1998), The rover named Sojourner was a "six-wheeled geologist" exploring the surface of Mars.

Magellan Performed a detailed radar mapping of the surface of Venus ('90-'94), burned up in the atmosphere of Venus at end of mission.

Voyager 1&2 Explored the Jovian planets of Jupiter, Saturn, Uranus, and Neptune between '77-'89.

Viking 1&2 Mars orbiter and landers (1976), sent back a wealth of information about Mars.

VeneraFormer Soviet Union sent landing probes to Venus (Venera 9 & 10) in 1972. The probe lived for about 1 hour sending back pictures and data before most of its circuitry was melted from the seering heat.

Pioneer 10&11 Studied Jupiter and Saturn back in 1974.

Mariner 10 Flew by Venus and Mercury sending back pictures in 1973.

Apollo Missions to the Moon, One mission involved a moon rover to travel around on the surface. First moon landing was Apolla

Future missions that are being planned.

[Long list of space probes and satellites.]

Apollo 17 astronaut Harrison Schmitt standing next to a large Moon boulder. Photo courtesy of the NSSDC Photo Gallery.

Now that we know how the observations were made, lets look at how these observations have shaped our understanding of the geology of these places.

Summary of Geological Characteristics [Note: 1 Astronomical Unit (AU) = 1.49x1011 meters = average distance the earth is away from the sun. To convey a good feeling for how far away the planets are from earth, I've expressed their distance in terms of how long it would take the Space Shuttle flying at 17,500 miles per hour (direct course) to get to the planet or object.]

Sun - 350,000 times more massive than earth; 10,000,000 times more voluminous; surface temperature 5,800 oK (note that room temperature is 293 oK, rocks melt at about 1400 oK), inner core temperature of 15,600,000 oK. Composition - Hot gaseous object with mostly helium and hydrogen. Fuel - Nuclear fusion (in the core) is the tremendous source of the Sun's energy. Space Shuttle travel days to get there from Earth = 222 days

Terestrial Planets - planets that are "rocky", relatively small, and close to the sun. Mercury - no atmosphere, small magnetic field, long "days", large temperature fluctuations Landforms - Scarps (or cliffs) have been formed possibly from the cooling of the planet, weird terrain can be found opposite of a large asteroid impact crater (Caloris Basin), high density, and has been geologically dead for a long time (such that, no volcanic or plate tectonic activity) Size - little bigger than the Earth's moon, 6/100 of the Earth's mass Space Shuttle travel days = 135 days, 0.39 AU from the Sun Venus - thick atmoshere, 96% CO2, 90 times the pressure of earth's atmosphere, temperatures remain about

constant at 600 oK (hot enough to melt lead), no magnetic field, no plate tectonics, volcanic activity has been indirectly observed. Landforms - thousands of volcanic structures, shield volcano eruptive style, volcanic domes Size - 8/10 of the Earth's mass Space Shuttle travel days = 62 days, 0.72 AU from the Sun Earth - (Already have learned about the Earth and its landforms.) Size - (Earth) Space Shuttle travel days = 0 days, 1.0 AU from the Sun Mars - thin atmosphere, 95% CO2, no magnetic field, no plate tectonics, volcanic activity in geologically

recent past, 7/1000 the earth's pressure Summary of Mars Geology From the Pathfinder Mission Landforms - Largest known volcanoes in the Solar System, Northern hemisphere contains lowlands, Southern hemisphere contains the highlands, polar regions have ice caps (water and carbon dioxide), temperatures fluctuate around -40oC, Valles Marineris (AVI Movie) is the "Grand Canyon" of Mars (4,000 km long, 120 km wide, and 7 km deep), has evidence for surface water in the geologic past - run-off channels and outflow channels have been observed, no liquid water has been observed, may have abundant frozen water in the form of permafrost, wind storms and landslides are present on the surface. Size - 1/10 of the Earth's mass Space Shuttle travel days = 111 days, 1.5 AU from the Sun

Jovian Planets - planets that are gaseous, relatively large, and further from the sun. Average densities are significantly less than the Earth's however the cores of the jovian planets can be very dense. Jupiter - The "surface" features are governed by fluid dynamics, composed of 86% hydrogen and 14% helium, emits more radiant energy than it absorbs, light bands in atmosphere represent ascending gases, dark colored bands are descending gases, the "Red Spot" is a huge hurricane-like storm that has been swirling for at least 300 years Results of Galileo's planetary probe that was shot into Jupiter's atmosphere Size - 318 times the Earth's mass Space Shuttle travel years = 2.6 years, 5.2 AU from the Sun Jupiter's Moons are some of the most fascinating places in the Solar System - Io, Europa, Ganymede, Callisto Saturn - Planet with the prominent rings (note that all the jovian planets have rings but some are quite faint), 92% hydrogen, 7.4% helium, surface is very dynamic, 1500 km/hr winds (compare to 160 km/hr winds in a hurricane on earth), contains large cyclonic storms similar to the "Red Spot" on Jupiter, emits more radiant energy than it absorbs Size - 95 times the Earth's mass

Space Shuttle travel years = 5.2 years, 9.5 AU from the Sun Uranus - atmospheric composition is very similar to Jupiter and Saturn, does not emit more radiant energy than it absorbs, inner solid core has a strange rotation - the axis of rotation is parallel with its orbital plane (the Earth's is perpendicular), appearance is somewhat hazy and atmosphere features are difficult to identify. Size - 14 times the Earth's mass Space Shuttle travel years = 11.1 years, 19.2 AU from the Sun Neptune - very similar to Uranus, Voyager probes did identify a clear "Blue Spot" hurricane like storm similar to the giant Red Spot on Jupiter, winds exceed 1000 km/hr, Size - 17 times the Earth's mass Space Shuttle travel years = 17.6 years, 30 AU from the Sun Pluto and other objects - Not much is known about Pluto other than it is quite small and cold, temperatures are

estimated at -210oC, some have argued that Pluto should not be classified as a planet and is more like a large asteroid. A newly opened science museum doesn't even put Pluto into its mosaic of the planets. Some theories suggest Pluto may have once been a satellite of Neptune that experienced a massive collision to put it into orbit around the Sun instead of Neptune. Size (Pluto) - 3/1000 of the Earth's mass Space Shuttle travel years = 23.4 years, 40 AU from the Sun Nearest Star (Alpha Centauri) Space Shuttle travel time = 168,000 years Nearest Galaxy (Andromeda Galaxy) Space Shuttle travel time = 88 billion years* [The Clouds of Megallan galaxy are a actually closer to the Milky Way than the Andromeda Galaxy.] Edge of the known Universe Space Shuttle travel time = 14 trillion years* (*These numbers make little sense because the Universe is believed to be expanding much faster than the Shuttle can fly. The Andromeda Galaxy and the edge of the Universe are moving away from us much faster than the shuttle can fly. And the number of years is older than the Universe itself! But they do give you a "feeling" for the size of the Universe )

Geological Evolution of Planets

According to the Big Bang theory, almost all the atoms of the universe began as hydrogen or helium. Atoms that are heavier, such as carbon, oxygen, nitrogen, iron, uranium, etc., are believed to have formed in fusion reactions within stars. Thus, you, I, and most of the earth are composed mainly of "star dust".

It is believed that our solar system formed from the gravitational collapse and coalescence of a "cloud" of interstellar star dust. Most of the matter collapsed into the center to form what is called a protosun at the center and protoplanets encircling the protosun. The matter that formed the sun was sufficiently large to produce nuclear fusion reactions at the core. [Jupiter came close to being big enough to produce fusion reactions but, lucky for us, didn't.] After the collapsing matter sufficiently cooled, the protoplanets became planets. Upon cooling chemical differentiation was happening where heavy elements sunk closer to the core (like iron) and the lighter elements went to the surface.

The Moon has an interesting evolution. The theories presented to explain its evolution include 1) coformation, 2) capture, 3) daughter or fission, and 4) impact. Many scientist favor the impact theory which suggests an object flying through the early solar system collided with the earth and the pieces from the collision formed the resulting moon.

The atmospheres of the early planets Venus, Earth, and Mars, are believed to have evolved via a primary and

secondary atmosphere. All three planets had the same primary atmosphere of light gases of hydrogen, helium, and methane (CH4). The primary atmosphere of the planets "evaporated" into space and was lost. A secondary

atmosphere developed via outgassing of volcanic activity composed of CO2, SO2, and nitrogen compounds.

On the earth, just the right amount of greenhouse gases (mainly CO2) dissolved or chemically combined into

the surface. This caused the right temperatures to let the water vapor condense and form oceans. On Venus, the greenhouse gases never left the atmosphere, producing more heat trapping conditions and preventing water in the form of vapor from condensing. This is commonly referred to as the "runaway greenhouse effect". On Mars the reverse is true. So much greenhouse gases "leaked" into space or chemically combined with the surface that Mars got quite cold. The early planet of Mars probably had a warmer atmosphere, blue sky, and liquid water. Mars experienced a "reverse greenhouse effect".

Life Elsewhere?

Sigmund Feud once said "...great revolutions in the history of science have but one common, and ironic, feature: they knock human arrogance off one pedestal after another of our previous conviction about our own self-importance." The scientific revolutions to which he is referring are mainly the Copernican Revolution (Earth is not the center of the Solar System), Darwin Evolutionism, and Unconscious/Sociobiology. This last category was, to a certain degree, showing the personal bias of Feud.

So why do I present this statement in this category? (I'll let you answer this question.)

"Are we alone?" is one of the most fascinating and philosophically important questions of all time. To approach this question scientifically, we need to (i.) examine the definition of "life", (ii.) the current evidence that might suggest an answer, and (iii.) the probability of life in the Universe existing even if we haven't directly observed evidence for such.

In the October, 1994, issue of Scientific American, Carl Sagan wrote a very informative exposition on this topic. The title of his article was "The Search For Extraterrestrial Life: The earth remains the only inhabited world known so far, but scientists are finding that the universe abounds with the chemistry of life."

On the definition of life Sagan writes

" 'I'll know it when I see it.' is an insufficient answer...one might identify life as anything that ingests, metabolizes, and excretes, but this description applies to my car or to a candle flame...Biochemical definitions -- for example, defining life in terms of nucleic acids, proteins and other molecules -- are clearly chauvinistic. Would we declare an organism that can do everything a bacterium can dead if it was made of very different molecules? The definition I like the best -- life is any system capable of reproduction, mutation and reproduction of its mutations."

Most likely places within our Solar System to find signs of life (or past life) are in fossilized records on Mars and/or underneath Europa's icy surface which may lie a vast liquid water ocean. Magnetic data, recently gathered by the Galileo Space Probe, suggests a pattern consistent with Europa having a liquid ocean beneath a thick crust of ice.

Meteorite ALH84001 - So what's the big fuss over this rock? Many highly respected scientist have argued that when examined closely it shows evidence for life on Mars (several billion years ago) from microscopic fossils contained in the rock! A tantilizing possibility but at this point it is still being debated.

Greenbank Equation (or the Drake Equation)

The Greenbank Equation represents an effort to place a numerical probability on the possibility that life exists out there somewhere. Some components of this equation are well known and some are meer speculation. To fully appreciate this equation, one needs to be familiar with concepts in Astronomy, Biology, and little bit of Geology.

In essence, it attempts to put a numerical estimate on the number of technological civilizations present in our galaxy - the Milky Way. The formula tries to establish numbers on questions that factor into making such an estimate. These factors include: rate of star formation, probability of the star having planets, planets with the right conditions necessary for life, will life emerge if given the right conditions, probability of life evolving intelligence, intelligence producing technologically advanced civilization, average lifetime for a technologically advanced civilization.

Some scientist are becoming somewhat pessimistic about finding intelligent life elsewhere. International Conference on "Astrobiology" - "I don't think there is anything out there at all except ourselves..." states British paleontologist Simon Conway Morris. "Microbial life is probably widespread in the universe...However, complex life - animals and higher plants - is likely to be far more rare than is commonly assumed." exclaims Peter Ward, geologist at the University of Washington in Seattle. Source of information: Pioneer Press article (4/16/00) with the title Dreams of extraterrestrial civilizations are fading.

The real purpose for the Stout clock tower has been uncovered! (humor)

Planetary Geology - Related Web Links

Mars Exploration Rover Missions - Scheduled for launch on May 30, 2003 and June 25, 2003.

Powers of 10 animation. Fly in a ship that goes from the outer reaches of space to the inner reaches of the atom. Mars Landscape - Computer enhanced images of the Martian landscape. Gives you the feeling you are actually there. Origin of Life - NPR program May 14, 1999 (requires a free RealPlayer), Local File NASA's Planetary Photojournal Solar System - A multimedia tour of the Solar System (excellent site) History of Space Exploration - A very nice site with just about all the information you would need. The Planets - CalTech site on the planets in the Solar System. Solar System Simulator - Jet Propulsion Laboratory (JPL) Exploring the Solar System - A web site sponsored by the New York Times Web Pages Related To The Search For Extraterrestrial Life Drake Equation Extra-Solar Planets - Yahoo web links Planetary Society

Harvard's SETI Home Page UC-Berkeley's SETI Google - Search for Planetary Geology Google - Search for Planetary Evolution Google - Search for Exobiology or Astrobiology

Review Quizzes Section 10

Review Quiz Section 10 Tarbuck and Lutgens, Essentials of Geology, Self-Quiz (Select Chapter Deserts and Wind)

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Mineral, Rock, and Fossil Gallery

[Jump to igneous, sedimentary, metamorphic, minerals, strategic minerals, fossils]

Igneous Rocks

Amygdaloidal Andesite Lava

Frothy Obsidian

Obsidian

Basalt Scoria

Red Granite

Rhyolite Lava

White Granite

Black Granite Gabbra

Dark Basalt Lava

Light Rhyolite Lava

Pumice ("The floating rock")

Granite

Vesicular Basalt

Sedimentary Rocks

Arkose Sandstone

Coarse Arkose Sandstone

Conglomerate

Limestone

Limestone

Biochemical (Non-detrital)

Shell Fossil Limestone

Volcanic Tuff

Sandstone (This type of stone is

abundant along the Red Cedar State Trail.)

Siltstone

Mudstone

Pink Quartz Sandstone

Fossil Non-detrital

Fossil Limestone

Sandstone

Black Shale

White Sandstone

Metamorphic Rocks

Colored Quartzite

Greenschist Schist

Mica Schist

Morton Gneiss

Slate

Hornblende Gneiss

Kyanite Quartzite

Marble

Quartz Mica Schist

Minerals

Calcite

Close-up of Calcite showing birefringence. There is only one 'S' below the transparent mineral.

Elemental Copper

Gypsum

Halite

Magnetite

Pyrite (or Fool's Gold)

Fluorite

Galena (Wisconsin's State Mineral!)

Geode Quartz (Inside material is a quartz.)

Oolitic Hematite

Kaolinite

Muscovite

Strategic Minerals

Corundum

Uses: Abrasive mineral, cutting and grinding tools

Garnet Uses: Abrasive mineral, cutting and grinding tools

Alunite Uses: Alloys, aircraft, tools, equipment

Bauxite (combination of minerals) Uses: Alloys, beverage cans, tools

Cryolite Uses: Alloys, tools, equipment

Stibnite Uses: Alloys, infrared photography, rubber goods

Siderite

Uses: Alloys, steel industry

Cerussite Uses: Lead industry, alloys, batteries, x-ray equipment

Galena Uses: Lead industry, alloys, ammunition, batteries, x-ray equipment

Lepidolite Uses: Atomic energy, batteries, welding/brazing

Magnesite Uses: Alloys, aircraft, metallurgy, pyrotechnics

Psilomelane Uses: Alloys, chemicals, metallurgy, antiseptics

Oripment Uses: Poisons, pigments, wood preservatives

Arsenopyrite Uses: Poisons, dyes, pyrotechnics, leather industry

Barite Uses: Chemicals, explosives, paints

Beryl Uses: Alloys, atomic energy, space vehicles

Chromite Uses: Alloys, aircrafts, autos, metallurgy

Cobaltite Uses: High temperature alloys, armor-piecing shells, paints

Pryolusite Uses: Alloys, ceramics, dyes, metallurgy

Cinnabar Uses: Chemicals, mercury products

Biotite Uses: Electrical insulators, roofing material, stove and furnace materials

Muscovite Uses: Electrical insulators, fillers in paper, rubber and plastics

Molybdenite Uses: Airplane, auto industry, steel alloys

Nickeline Uses: Alloys, armor-plating, auto industry, ordnance

Columbite Uses: Filaments, high-temperature alloys, tools

Azurite Uses: Copper industry

Bornite Uses: Copper industry

Chalcopyrite Uses: Copper industry

Malachite Uses: Alloys, ammunitions, brass, copper industry

Fluorite Uses: Refrigerants, propellants, aluminum and steel industry

Sylvite Uses: Chemical industry, fertilizers

Rock Crystal (Quartz) Uses: Optical instruments, abrasives, glass industry

Halite Uses: De-icer for roads, cooking, bleaches, soap

Celestite Uses: Heat treating metal, pyrotechnics, ceramics

Cassiterite Uses: (Tin mineral), Alloys, bronze, canning

Rutile Uses: Pigment in paints, alloys, space vehicles

Graphite Uses: Pencils, lubricants, pigments, paints

Hematite Uses: Alloys, steel industry

Limonite Uses: Alloys, steel industry

Magnetite Uses: Alloys, steel industry

Scheelite Uses: Steel alloys, chemical industry, dental products

Vanadinite Uses: Steel alloys, auto and railway equipment

Carnotite Uses: Atomic industry, military purposes

Uraninite Uses: Atomic industry, military purposes

Sphalerite Uses: (Zinc mineral), Alloys, brass, galvanized metal, pigments, paints

Fluorescence (Becomes luminescent during exposure to ultraviolet or infrared light.) Phosphorescence (Stays luminescent even after exposure to ultraviolet or infrared light.)

Regular Light and Infrared Light Exposure

Here is a list of the minerals contained in the picture above:

Willemite, from Franklin Furnace, New Jersey Fluorite, from Weardale, England Sphalerite, from Tsumeb, Soutwest Africa Fluorite, from Clay Center, Ohio Wernerite, from Grenville, P.Q. Canada Semi-Opal, from Humboldt County, Nevada

The mineral in the middle of the bottom row is also slightly radioactive.

Fossils (Actual and Replicas)

Paleozoic Era

Trilobite, Middle Cambrian

Trilobite, Early Devonian

Trilobite, Ordovician

Trilobite, Early Cambrian

Gastropods, Permian (Actual Fossils)

Trilobite, Devonian

Trilobite, Early Devonian

Trilobite, Middle Cambrian

Trilobite, Ordovician

Mesozoic Era

Tyrannosauras Rex Skull (scaled

replica), Cretaceous

Tyrannosauras Rex Skull (scaled replica, close-up), Cretaceous

Pterodactyl, Late Jurassic

Cenozoic Era

Unidentified Insect in Amber, Miocene Epoch (Actual Fossil)

PowerPoint slide show of some fossil specimens on display at the Minnesota Science Museum (10 Mb).

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quizzes

Section 1 Introduction, Historical Development, Geologic Time Section 2 Rock Cycle, Minerals, Raw Materials Section 3 Plate Tectonics, Earthquakes, Volcanoes Section 4 Igneous Rocks, Sedimentary Rocks, Metamorphic Rocks Section 5 Hydrology, Mass Movement, Weathering Section 6 Engineering Properties of Soils, Soil Cave-ins, OSHA Regulations for Excavations Section 7 Compaction, Dewatering, Stress and Settlement, Foundations, Pilings Section 8 Retaining Structures, Earthwork Contracts, Soil Reports

Section 9 Glaciers, Shoreline and Beaches

Section 10 Deserts, Sand Dunes, Planetary Geology

*New* Practice Midterm Exam With Automatic Evaluation (spreadsheet format), for students enrolled in PHYS-258. If it requests a password, simply click on cancel and it should still appear.

Practice Final Exam With Automatic Evaluation (spreadsheet format), for students enrolled in PHYS-258. If it requests a password, simply click on cancel and it should still appear.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 1

A link to these question's answers are provided at the bottom of this page. I would suggest that you write down your answer on paper then check to see if it is correct. Getting 2 or less incorrect out of 10 questions is a good performance. Further studying is recommended if you get more than 4 out of 10 incorrect.

1. The __________ era of geologic time is considered the "age of mammals". a) Mesozoic b) Cenozoic c) Paleozoic d) none of the above

2. The principle of uniformitarianism states that the present is the key to the past. a) True b) False

3. The largest standard division of geologic time is an era. a) True b) False

4. The two geological periods that mark (or indicate an extinction between them) the great dinosaur extinction are a) Cretaceous and Jurassic. b) Triassic and Permian. c) Tertiary and Cretaceous. d) Quaternary and Tertiary. e) None of the above.

5. What is the estimated percentage of houses in the U.S. that exceed the maximum concentration of radon using the EPA guidelines? a) less than 1% b) 6% c) 21% d) 85% e) greater than 90%

6. Radioactive dating techniques cannot date rocks older than a) 10,000 years b) 1 million years c) 1 billion years d) none of the above.

7. Carbon dating techniques can be used to date the flint arrow-head of an ancient arrow. a) True b) False

8. An unconformity is what? a) A buried fault or fracture with older rocks above and younger rocks below. b) A buried surface of erosion with older strata above and younger strata below. c) A buried fault or fracture with younger strata above and older strata below. d) A buried surface of erosion separating younger strata above from older strata below.

9. Which is the name of an eon in the geologic time scale? a) Triassic b) Cambrian c) Phanerozoic d) Mesozoic e) none of the above

10. Which of the following is true about Radon gas? a) It is not harmful as long as you don't walk barefoot in the basement. b) It has a daughter nucleus that is also radioactive. c) All radon gas has a parent nucleus of lead. d) Both b and c above. e) none of the above Example short answer question: 11. Describe the factors that influence radon gas concentration in residential housing.

Link to Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 1

Solutions

1. The __________ era of geologic time is considered the "age of mammals". a) Mesozoic b) Cenozoic c) Paleozoic d) none of the above

2. The principle of uniformitarianism states that the present is the key to the past. a) True b) False

3. The largest standard division of geologic time is an era. a) True b) False

4. The two geological periods that mark (or indicate an extinction between them) the great dinosaur extinction are a) Cretaceous and Jurassic. b) Triassic and Permian. c) Tertiary and Cretaceous. d) Quaternary and Tertiary. e) None of the above.

5. What is the estimated percentage of houses in the U.S. that exceed the maximum concentration of radon using the EPA guidelines? a) less than 1% b) 6% c) 21% d) 85% e) greater than 90%

6. Radioactive dating techniques cannot date rocks older than a) 10,000 years b) 1 million years c) 1 billion years d) none of the above.

7. Carbon dating techniques can be used to date the flint arrow-head of an ancient arrow. a) True b) False

8. An unconformity is what? a) A buried fault or fracture with older rocks above and younger rocks below. b) A buried surface of erosion with older strata above and younger strata below. c) A buried fault or fracture with younger strata above and older strata below. d) A buried surface of erosion separating younger strata above from older strata below.

9. Which is the name of an eon in the geologic time scale? a) Triassic b) Cambrian c) Phanerozoic d) Mesozoic e) none of the above

10. Which of the following is true about Radon gas? a) It is not harmful as long as you don't walk barefoot in the basement. b) It has a daughter nucleus that is also radioactive. c) All radon gas has a parent nucleus of lead. d) Both b and c above. e) none of the above Example short answer question: 11. Describe the factors that influence radon gas concentration in residential housing.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 15, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 2

Link to Solutions at the Bottom.

1. The mineral gold belongs to the silicate family of minerals. a) True b) False

2. Ionic chemical bonds are usually stronger than covalent chemical bonds. a) True b) False

3. Since Talc has a Mohs hardness of 1 and Apatite has a hardness of 4, we can state that a) Apatite is 4 times harder than Talc. b) Talc can scratch Apatite. c) Apatite cannot scratch Calcite. d) only that Apatite is harder than Talc. e) none of the above.

4. The mineral Galena has a chemical composition of PbS. To which mineral family does Galena belong? a) Silicates b) Sulfides c) Sulfates d) Halides

5. Which response best defines a mineral and a rock? a) a rock has an orderly, repetitive, geometrical, internal arrangement of mineral grains; a mineral is a lithified or consolidated aggregate of rocks. b) a mineral consists of its constituent atoms arranged in a geometrically repetitive structure; in a rock, the constituent atoms are randomly bonded without any geometric pattern. c) in a mineral the constituent atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of different mineral grains. d) a rock consists of atoms bonded in a regular, geometrically predictable arrangement; a mineral is a lithified or consolidated aggregate of different rock particles.

6. What type of mining method scrapes surface material off of the ground in a large area? a) Underground Mining b) Strip Mining c) Ore Mining d) Placer Mining e) none of the above

7. Coal, natural gas, and uranium are examples of non-renewable fossil fuels. a) True b) False

8. The color of a mineral in powdered form is called its striations. a) True b) False

9. The luster of a mineral refers to a) the tendency for a mineral to break along smooth planar surfaces. b) its color in reflected light. c) its color in a finely powdered form. d) threadlike lines or narrow bands that run across the crystal face of a mineral. e) none of the above

10. Suppose the mineral Chromite is found in relative abundance in South Africa, but this country has not mined any of it out of the ground. Chromite is important to this country's economy because it contains the element chromium - which is used to harden steel. Is Chromite a strategic mineral for South Africa? a) True b) False

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 2

Solutions

1. The mineral gold belongs to the silicate family of minerals. a) True b) False

2. Ionic chemical bonds are usually stronger than covalent chemical bonds. a) True b) False

3. Since Talc has a Mohs hardness of 1 and Apatite has a hardness of 4, we can state that a) Apatite is 4 times harder than Talc. b) Talc can scratch Apatite. c) Apatite cannot scratch Calcite. d) only that Apatite is harder than Talc. e) none of the above.

4. The mineral Galena has a chemical composition of PbS. To which mineral family does Galena belong? a) Silicates b) Sulfides c) Sulfates d) Halides

5. Which response best defines a mineral and a rock? a) a rock has an orderly, repetitive, geometrical, internal arrangement of mineral grains; a mineral is a lithified or consolidated aggregate of rocks. b) a mineral consists of its constituent atoms arranged in a geometrically repetitive structure; in a rock, the constituent atoms are randomly bonded without any geometric pattern. c) in a mineral the constituent atoms are bonded in a regular, repetitive, internal structure; a rock is a lithified or consolidated aggregate of different mineral grains. d) a rock consists of atoms bonded in a regular, geometrically predictable arrangement; a mineral is a lithified or consolidated aggregate of different rock particles.

6. What type of mining method scrapes surface material off of the ground in a large area? a) Underground Mining b) Strip Mining c) Ore Mining d) Placer Mining e) none of the above

7. Coal, natural gas, and uranium are examples of non-renewable fossil fuels. a) True b) False

8. The color of a mineral in powdered form is called its striations. a) True b) False

9. The luster of a mineral refers to a) the tendency for a mineral to break along smooth planar surfaces. b) its color in reflected light. c) its color in a finely powdered form. d) threadlike lines or narrow bands that run across the crystal face of a mineral. e) none of the above

10. Suppose the mineral Chromite is found in relative abundance in South Africa, but this country has not mined any of it out of the ground. Chromite is important to this country's economy because it contains the element chromium - which is used to harden steel. Is Chromite a strategic mineral for South Africa? a) True b) False

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 3

Link to Solutions at the Bottom.

1. Plate tectonic processes explain: a) belts of volcanic activity. b) oceanic tides. c) the geologic column. d) the evolution of life forms. e) all the above.

2. The amplitude of a seismic wave from a magnitude 9 earthquake is ____ times as large as the amplitude from an earthquake of magnitude 7. a) 2 b) 1/2 c) 10 d) 1000 e) none of the above

3. Composite volcanoes usually have a magma with a very low viscosity. a) True b) False

4. Sometimes during earthquakes stable soil is transformed into a fluid material that is unable to support buildings or other structures. This transformation is called a) uniformitarianism. b) lithification. c) liquefaction. d) sluification. e) none of the above.

5. Which part of the earth is considered liquid? a) Crust b) Mantle c) Outer Core d) Inner Core

6. Another name for a seismic sea wave is a) tsunami. b) elastic sea wave. c) bonzai. d) seamount. e) none of the above.

7. Mt. St. Helens is what type of volcano? a) composite b) shield c) differentiated d) largest ever recorded e) none of the above

8. The asthenosphere is a relatively cool and rigid shell that overlies the lithosphere. a) True b) False

9. Which is not evidence that supports plate tectonic theory? a) pattern of seismic activity. b) magnetic patterns in rock along the mid-ocean ridge. c) rock strata along continents. d) earthquake foci descending along plate boundaries. e) slow decrease of the earth’s rotation.

10. Consider three buildings that have similar construction but have a height of 4, 8, and 12 floors tall, respectively. If they all experience the same amplitude of ground shaking and only the 8 floor tall building collapses, it is mainly because of a) that building being unlucky. b) that buildings inability to withstand repeated reversals of inelastic strain. c) the natural frequency of that building. d) the soil beneath the building could have experienced lithification. e) all the above except a.

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 3

Move your pointer over top of the gray box to the left of each question to see the answer.

1. Plate tectonic processes explain: a) belts of volcanic activity. b) oceanic tides. c) the geologic column. d) the evolution of life forms. e) all the above.

2. The amplitude of a seismic wave from a magnitude 9 earthquake is ____ times as large as the amplitude from an earthquake of magnitude 7. a) 2 b) 1/2 c) 10 d) 1000 e) none of the above

3. Composite volcanoes usually have a magma with a very low viscosity. a) True b) False

4. Sometimes during earthquakes stable soil is transformed into a fluid material that is unable to support buildings or other structures. This transformation is called a) uniformitarianism. b) lithification. c) liquefaction. d) sluification. e) none of the above.

5. Which part of the earth is considered liquid? a) Crust b) Mantle c) Outer Core d) Inner Core

6. Another name for a seismic sea wave is a) tsunami. b) elastic sea wave. c) bonzai. d) seamount. e) none of the above.

7. Mt. St. Helens is what type of volcano? a) composite b) shield c) differentiated d) largest ever recorded e) none of the above

8. The asthenosphere is a relatively cool and rigid shell that overlies the lithosphere. a) True b) False

9. Which is not evidence that supports plate tectonic theory? a) pattern of seismic activity. b) magnetic patterns in rock along the mid-ocean ridge. c) rock strata along continents. d) earthquake foci descending along plate boundaries. e) slow decrease of the earth’s rotation.

10. Consider three buildings that have similar construction but have a height of 4, 8, and 12 floors tall, respectively. If they all experience the same amplitude of ground shaking and only the 8 floor tall building collapses, it is mainly because of a) that building being unlucky. b) that buildings inability to withstand repeated reversals of inelastic strain. c) the natural frequency of that building. d) the soil beneath the building could have experienced lithification. e) all the above except a.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was

last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 4

Link to Solutions at the Bottom.

1. Which of the following are textures of igneous rocks? a) granular, cinders, pyroclastic b) glassy, cinders, pumice c) glassy, aphanitic, granular d) granular, glassy, tabular e) none of the above

2. Which texture of igneous rocks indicate the slowest cooling or crystallization? a) glassy b) aphanitic c) phaneritic d) basaltic

3. A metamorphic rock must come into contact with magma before it can become a sedimentary rock. a) True b) False

4. Detrital sedimentary rocks have a clastic (broken or fragmental) texture consisting of a) clasts, pebbles, and clay. b) clasts, matrix, and cement. c) matrix, cement, quartz. d) evaporites, cement, and calcite.

5. A sedimentary ___________ is an assemblage of mineral or rock features that reflect the depositional environment in which the sediments were laid down. a) contact b) regionite c) facies d) foliation

6. Metamorphic rocks that have formed from directed pressure exhibit mineral grains that have a flattened appearance. This type of metamorphic rock has a(n) __________________ texture. a) foliated b) stretched c) imbedded d) non-foliated e) none of the above

7. The difference between a conglomerate and breccia sedimentary rock is a) in the chemical composition of the rock. b) in the lithification process each has undergone. c) in the way that one has rounded rock fragment edges and the other has angular edges for the clasts. d) that one is composed of small mineral grains the other large mineral grains.

8. A metamorphic facies indicates the environment that molten magma crystallized to form the metamorphic rock. a) True b) False

9. The Bowen’s Reaction series gives us information on the rate at which rocks will undergo metamorphism. a) True b) False

10. The major influences that cause metamorphism in rocks are a) water, pressure, and air. b) heat, pressure, and melting. c) lithification, heat, and weathering. d) heat, pressure, and chemical fluids. e) none of the above.

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 4

Solutions

1. Which of the following are textures of igneous rocks? a) granular, cinders, pyroclastic b) glassy, cinders, pumice c) glassy, aphanitic, granular d) granular, glassy, tabular e) none of the above

2. Which texture of igneous rocks indicate the slowest cooling or crystallization? a) glassy b) aphanitic c) phaneritic d) basaltic

3. A metamorphic rock must come into contact with magma before it can become a sedimentary rock. a) True b) False

4. Detrital sedimentary rocks have a clastic (broken or fragmental) texture consisting of a) clasts, pebbles, and clay. b) clasts, matrix, and cement. c) matrix, cement, quartz. d) evaporites, cement, and calcite.

5. A sedimentary ___________ is an assemblage of mineral or rock features that reflect the depositional environment in which the sediments were laid down. a) contact b) regionite c) facies d) foliation

6. Metamorphic rocks that have formed from directed pressure exhibit mineral grains that have a flattened appearance. This type of metamorphic rock has a(n) __________________ texture. a) foliated b) stretched c) imbedded d) non-foliated e) none of the above

7. The difference between a conglomerate and breccia sedimentary rock is a) in the chemical composition of the rock. b) in the lithification process each has undergone. c) in the way that one has rounded rock fragment edges and the other has angular edges for the clasts. d) that one is composed of small mineral grains the other large mineral grains.

8. A metamorphic facies indicates the environment that molten magma crystallized to form the metamorphic rock. a) True b) False

9. The Bowen’s Reaction series gives us information on the rate at which rocks will undergo metamorphism. a) True b) False

10. The major influences that cause metamorphism in rocks are a) water, pressure, and air. b) heat, pressure, and melting. c) lithification, heat, and weathering. d) heat, pressure, and chemical fluids. e) none of the above.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 5

Link to Solutions at the Bottom.

1. Over 10% of all the water on the Earth is in the form of groundwater. a) True b) False

2. When mass movement occurs and the material maintains continuing contact with the surface on which it moves but the internal particles are not extensively rearranged is an example of a) flow. b) heave. c) fall. d) slide.

3. The proper units for discharge are a) (velocity)x(time). b) (volume)x(time). c) (volume)/(force). d) (volume)/(distance). e) none of the above.

4. Which of the following is true about an area that has permafrost? a) During the highest temperature in the summer, the ground will thaw completely. b) Foundations for houses should be as shallow as possible. c) There will always be ice on the surface of the ground. d) The water created by melting ice on the surface usually infiltrates readily into the ground becoming groundwater. e) none of the above.

5. A hydrograph is a plot of a) water volume as a function of time. b) river velocity as a function of time. c) discharge as a function of time. d) discharge as a function of river velocity. e) none of the above.

6. Mass movement occurs as a slide, heave, fall, flow. Which of the following represents a slide? a) slump b) rock avalanche c) solifluction d) mudflow e) none of the above

7. Many old stream valleys contain a) rapids. b) turbulent water flow. c) large gradients. d) meanders.

8. Two examples of chemical weathering are a) oxidation and frost action. b) frost action and thermal expansion/contraction. c) hydration and dissolution. d) all the above. e) none of the above.

9. The chemical weathering process in which water is structurally added to the rock material is called a) hydration. b) calcining. c) dissolution. d) karsting. e) none of the above.

10. If two rocks have the same mass, but one is broken into several fragments and the other is not, the one broken up will chemically weather at a faster rate. a) True b) False

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 5

Solutions

1. Over 10% of all the water on the Earth is in the form of groundwater. a) True b) False

2. When mass movement occurs and the material maintains continuing contact with the surface on which it moves but the internal particles are not extensively rearranged is an example of a) flow. b) heave. c) fall. d) slide.

3. The proper units for discharge are a) (velocity)x(time). b) (volume)x(time). c) (volume)/(force). d) (volume)/(distance). e) none of the above.

4. Which of the following is true about an area that has permafrost? a) During the highest temperature in the summer, the ground will thaw completely. b) Foundations for houses should be as shallow as possible. c) There will always be ice on the surface of the ground. d) The water created by melting ice on the surface usually infiltrates readily into the ground becoming groundwater. e) none of the above.

5. A hydrograph is a plot of a) water volume as a function of time. b) river velocity as a function of time. c) discharge as a function of time. d) discharge as a function of river velocity. e) none of the above.

6. Mass movement occurs as a slide, heave, fall, flow. Which of the following represents a slide? a) slump b) rock avalanche c) solifluction d) mudflow e) none of the above

7. Many old stream valleys contain a) rapids. b) turbulent water flow. c) large gradients. d) meanders.

8. Two examples of chemical weathering are a) oxidation and frost action. b) frost action and thermal expansion/contraction. c) hydration and dissolution. d) all the above. e) none of the above.

9. The chemical weathering process in which water is structurally added to the rock material is called a) hydration. b) calcining. c) dissolution. d) karsting. e) none of the above.

10. If two rocks have the same mass, but one is broken into several fragments and the other is not, the one broken up will chemically weather at a faster rate. a) True b) False

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 6

Link to Solutions at the Bottom.

1. A cohesive soil with an unconfined compressive strength of _____ tsf may be classified as a Type A. a) 0.4 b) 1.2 c) 1.6 d) both b and c. e) none of the above.

2. If an entire soil sample can pass through a No. 100 sieve, it contains 100% fines. a) True b) False

3. The USCS soil classification system is mainly used by a) geologists. b) engineering consulting companies and soil-testing laboratories. c) state highway transportation officials. d) particle physicists.

4. If you know the weight of a soil sample both moist and dry, you can determine its water content. a) True b) False

5. For the USCS, the symbol G corresponds to a) silt. b) well graded. c) clay. d) sand. e) none of the above.

6. For a simple slope excavation, a Type B soil should have a slope of a) 1 ½ horizontal to 1 vertical distance. b) 1 horizontal to 1 vertical distance. c) ¾ horizontal to 1 vertical distance. d) none of the above.

7. The unconfined compressive strength of a clay soil is about _________ the cohesion of the soil. a) half b) equal to c) twice d) four times e) none of the above

8. The water content of a soil can be larger than 100%. a) True b) False

9. The approximate soil pressure (in the vertical direction) at a depth of 10 ft for an average soil is a) 100 lb/ft2 b) 1000 lb/ft2 c) 10,000 lb/ft2 d) 100,000 lb/ft2

10. A soil with a large coefficient of uniformity (via a grain-size distribution curve) is a soil that a) has particles all about the same size. b) always contains a large % passing by weight for a number 200 sieve. c) always contains a large % passing by weight for a 3/8 in sieve. d) has particles with diverse sizes.

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 6

Solutions

1. A cohesive soil with an unconfined compressive strength of _____ tsf may be classified as a Type A. a) 0.4 b) 1.2 c) 1.6 d) both b and c. e) none of the above.

2. If an entire soil sample can pass through a No. 100 sieve, it contains 100% fines. a) True b) False

3. The USCS soil classification system is mainly used by a) geologists. b) engineering consulting companies and soil-testing laboratories. c) state highway transportation officials. d) particle physicists.

4. If you know the weight of a soil sample both moist and dry, you can determine its water content. a) True b) False

5. For the USCS, the symbol G corresponds to a) silt. b) well graded. c) clay. d) sand. e) none of the above.

6. For a simple slope excavation, a Type B soil should have a slope of a) 1 ½ horizontal to 1 vertical distance. b) 1 horizontal to 1 vertical distance. c) ¾ horizontal to 1 vertical distance. d) none of the above.

7. The unconfined compressive strength of a clay soil is about _________ the cohesion of the soil. a) half b) equal to c) twice d) four times e) none of the above

8. The water content of a soil can be larger than 100%. a) True b) False

9. The approximate soil pressure (in the vertical direction) at a depth of 10 ft for an average soil is a) 100 lb/ft2 b) 1000 lb/ft2 c) 10,000 lb/ft2 d) 100,000 lb/ft2

10. A soil with a large coefficient of uniformity (via a grain-size distribution curve) is a soil that a) has particles all about the same size. b) always contains a large % passing by weight for a number 200 sieve. c) always contains a large % passing by weight for a 3/8 in sieve. d) has particles with diverse sizes.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 7

Link to Solutions at the Bottom.

1. Units of pressure are a) (Newtons)x(meters) b) (Newtons)/(centimeters) c) (centimeters)/Newtons) d) (Newtons)/(meters)3 e) none of the above.

2. Which of the following best describes the coefficient of consolidation? a) Describes the total amount of expected settlement. b) Is a unitless factor that indicates how long it will take for primary consolidation. c) The soil's water permeability does not influence the coefficient of consolidation. d) none of the above

3. Cohesionless soils usually settle very slowly compared to cohesive soils for equal loads. a) True b) False

4. A compactor that uses several rubber tires to compact soil is called a a) goatsfoot roller. b) sheepsfoot roller. c) pneumatic roller. d) steel roller.

5. In general, foundation footings should be no less than ____ feet deep. a) 1 b) 2 c) 3 d) 4

6. If a soil experiences a punching bearing capacity failure, then there is no soil beside the foundation that is pushed up. a) True b) False

7. The stress increment due to loading of a soil is always less than the overburden pressure before loading. a) True b) False

8. An end-bearing pile supports most of the load of a structure by the adhesion and friction of the pile driven into the ground. a) True b) False

9. The soil-bearing capacity factors, Nc, Nq, Nγ, are functions of the soils

a) angle of internal friction. b) cohesion. c) consolidation. d) depth surrounding the footing. e) none of the above.

10. Two of the three types of bearing capacity failures for soils include a) general and local. b) local and global. c) punching and global. d) punching and kicking. e) none of the above

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 7

Solutions

1. Units of pressure are a) (Newtons)x(meters) b) (Newtons)/(centimeters) c) (centimeters)/Newtons) d) (Newtons)/(meters)3 e) none of the above.

2. Which of the following best describes the coefficient of consolidation? a) Describes the total amount of expected settlement. b) Is a unitless factor that indicates how long it will take for primary consolidation. c) The soil's water permeability does not influence the coefficient of consolidation. d) none of the above

3. Cohesionless soils usually settle very slowly compared to cohesive soils for equal loads. a) True b) False

4. A compactor that uses several rubber tires to compact soil is called a a) goatsfoot roller. b) sheepsfoot roller. c) pneumatic roller. d) steel roller.

5. In general, foundation footings should be no less than ____ feet deep. a) 1 b) 2 c) 3 d) 4

6. If a soil experiences a punching bearing capacity failure, then there is no soil beside the foundation that is pushed up. a) True b) False

7. The stress increment due to loading of a soil is always less than the overburden pressure before loading. a) True b) False

8. An end-bearing pile supports most of the load of a structure by the adhesion and friction of the pile driven into the ground. a) True b) False

9. The soil-bearing capacity factors, Nc, Nq, Nγ, are functions of the soils

a) angle of internal friction. b) cohesion. c) consolidation. d) depth surrounding the footing. e) none of the above.

10. Two of the three types of bearing capacity failures for soils include a) general and local. b) local and global. c) punching and global. d) punching and kicking. e) none of the above

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 8

Link to Solutions at the Bottom.

1. At a construction site, there are usually three groups of people - owners, engineers, and contractors. In most instances, if the excavation encounters a foreseeable problem with the subsurface, this problem is the responsibility of a) the owner. b) the engineer. c) the contractor.

2. Which quantity best describes how the vertical pressure is related to the lateral or horizontal soil pressure? a) The coefficient of consolidation, cv.

b) The compression index, Cc.

c) The angle of internal friction, φ. d) The coefficient of earth pressure at rest, Ko.

e) none of the above

3. If an earthwork contract specifies a particular soil type to be used as embankment material, that material is considered a) classified. b) non-classified. c) designated. d) qualified.

4. A Gabion retaining wall consists of large wire cages filled with stones and linked together to retain soil. a) True b) False

5. In earthwork contracts, the cost of excavating is usually expressed in units of a) pounds per cubic feet. b) kilonewtons per cubic meter. c) dollars per ton. d) dollars per pound. e) dollars per cubic meter.

6. Retaining walls with a base that extends out underneath of the backfill soil is called a ______________ wall. a) simple gravity b) cantilever c) tie-back

7. The standard penetration test is commonly used to determine the friction ratio for a soils report. a) True b) False

8. A correction factor needs to be applied to the standard penetration test because a) each hammer blow might not exert the same force. b) penetration resistance increases with depth eventhough the soil type does not change. c) penetration resistance changes when the soil type changes. d) with increase in depth, one increases the chances of encountering pockets of air.

9. A large friction ratio implies a more cohesive soil. a) True b) False

10. A simple gravity retaining wall is considered stable against tipping over if a) the sum of all the horizontal forces equal zero. b) the sum of all the vertical forces equal zero. c) it is tied back. d) all the clockwise torques equal the counter clockwise torques.

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 8

Solutions

1. At a construction site, there are usually three groups of people - owners, engineers, and contractors. In most instances, if the excavation encounters a foreseeable problem with the subsurface, this problem is the responsibility of a) the owner. b) the engineer. c) the contractor.

2. Which quantity best describes how the vertical pressure is related to the lateral or horizontal soil pressure? a) The coefficient of consolidation, cv.

b) The compression index, Cc.

c) The angle of internal friction, φ. d) The coefficient of earth pressure at rest, Ko.

e) none of the above

3. If an earthwork contract specifies a particular soil type to be used as embankment material, that material is considered a) classified. b) non-classified. c) designated. d) qualified.

4. A Gabion retaining wall consists of large wire cages filled with stones and linked together to retain soil. a) True b) False

5. In earthwork contracts, the cost of excavating is usually expressed in units of a) pounds per cubic feet. b) kilonewtons per cubic meter. c) dollars per ton. d) dollars per pound. e) dollars per cubic meter.

6. Retaining walls with a base that extends out underneath of the backfill soil is called a ______________ wall. a) simple gravity b) cantilever c) tie-back

7. The standard penetration test is commonly used to determine the friction ratio for a soils report. a) True b) False

8. A correction factor needs to be applied to the standard penetration test because a) each hammer blow might not exert the same force. b) penetration resistance increases with depth eventhough the soil type does not change. c) penetration resistance changes when the soil type changes. d) with increase in depth, one increases the chances of encountering pockets of air.

9. A large friction ratio implies a more cohesive soil. a) True b) False

10. A simple gravity retaining wall is considered stable against tipping over if a) the sum of all the horizontal forces equal zero. b) the sum of all the vertical forces equal zero. c) it is tied back. d) all the clockwise torques equal the counter clockwise torques.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 9

Link to Solutions at the Bottom.

1. For a glacier to retreat, a) the rate of ablation must not exceed the rate of accumulation. b) the rate of calving must exceed the rate of ablation. c) the rate of ablation must exceed the rate of accumulation. d) none of the above.

2. Waves tend to converge on headlands and diverge in bays is a result of the process of _______________. a) refraction b) beach erosion c) spit formation d) water breaker

3. A medial moraine is developed a) on the side of a glacier. b) at the end of the glacier. c) in the bergschrund. d) in the middle of two coalesced glaciers. e) none of the above

4. The distance measured between two successful wave troughs is called the a) wave height. b) wave base. c) wavelength. d) wave frequency.

5. How do continental glaciers form? a) freezing of rivers. b) freezing of lakes. c) freezing of groundwater. d) none of the above.

6. Groins are artificial structures designed to produce beach erosion for the owners who build the groin. a) True b) False

7. The farthest advance of a glacier is marked by the __________ moraine. a) end b) terminal c) medial d) lateral

8. As you go from lower to higher latitudes on the planet, the altitude of the snow line in glaciers should a) increase. b) stay the same. c) decrease. d) very randomly e) none of the above

9. Which of the following theories best explains the reason why the earth experienced several periods of glaciation during the Pleistocene Epoch? a) Superposition b) Earth's precession c) Earth's orbit about the center of the galaxy d) Sea level decreased worldwide

10. The longshore current has a direction that is _____________ to the shoreline. a) perpendicular b) parallel c) non-directional (It is a fictitious water current.)

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 9

Solutions

1. For a glacier to retreat, a) the rate of ablation must not exceed the rate of accumulation. b) the rate of calving must exceed the rate of ablation. c) the rate of ablation must exceed the rate of accumulation. d) none of the above.

2. Waves tend to converge on headlands and diverge in bays is a result of the process of _______________. a) refraction b) beach erosion c) spit formation d) water breaker

3. A medial moraine is developed a) on the side of a glacier. b) at the end of the glacier. c) in the bergschrund. d) in the middle of two coalesced glaciers. e) none of the above

4. The distance measured between two successful wave troughs is called the a) wave height. b) wave base. c) wavelength. d) wave frequency.

5. How do continental glaciers form? a) freezing of rivers. b) freezing of lakes. c) freezing of groundwater. d) none of the above.

6. Groins are artificial structures designed to produce beach erosion for the owners who build the groin. a) True b) False

7. The farthest advance of a glacier is marked by the __________ moraine. a) end b) terminal c) medial d) lateral

8. As you go from lower to higher latitudes on the planet, the altitude of the snow line in glaciers should a) increase. b) stay the same. c) decrease. d) very randomly e) none of the above

9. Which of the following theories best explains the reason why the earth experienced several periods of glaciation during the Pleistocene Epoch? a) Superposition b) Earth's precession c) Earth's orbit about the center of the galaxy d) Sea level decreased worldwide

10. The longshore current has a direction that is _____________ to the shoreline. a) perpendicular b) parallel c) non-directional (It is a fictitious water current.)

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 10

Link to Solutions at the Bottom.

1. Which of the following best describes spectroscopic analysis? a) Identifying what wavelength of light an object is emitting gives us information about its chemical composition. b) Identifying what wavelength of light an object is emitting gives us information about the distance that object is away from us. c) Identifying what wavelength of light an object is emitting gives us information about how to image the object. d) Telescopes don't need to image planets in visible light. They can also use non-visible light to image objects.

2. Earth is the only object in our solar system that has ever had liquid water on its surface. a) True b) False

3. Deflation in a desert area is a process that involves a) abrasion. b) accumulation of ventifacts. c) sand dune collapse. d) movement of unconsolidated materials. e) none of the above.

4. The source of energy for the Sun is __________. a) nuclear fusion. b) nuclear fission. c) solar rays. d) plasma emissions.

5. Sand dunes that are parabolic shaped and have their points directed downwind are called _________ dunes. a) barchan b) longitudinal c) transverse d) star

6. Desert pavement can best be described as a) an accumulation of sand and silt particles, thus burying the larger rocks. b) an erosion of larger rocks producing large amounts of sand and silt. c) wind erosion blowing away all the small particles leaving the larger rocks. d) playa lake beds that have dried up and hardened.

7. The planet Venus has a very hot and thin atmosphere. Such that, it is hot enough to melt lead and has 7/1000 the earth's pressure. a) True b) False

8. Pluto can best be classified as what type of planet? a) Vulcan b) Terrestrial c) Jovian d) Martian

9. Which of the following statements best describes desertification? a) Due to natural processes, the land surrounding a desert slowly evolves into the desert. b) Due to changes in global wind patterns, some geographical areas can evolve into deserts. c) Due to changes in the earth's axis of rotation, some geographical areas can evolve into deserts. d) Improperly using the land surrounding deserts can contribute to the desert expanding geographically.

10. Intelligent alien life forms, from other planets outside our solar system, must exist. a) This statement is true according to the philosophy of science. b) This statement is false according to the philosophy of science. c) Since no life forms have been detected, one should conclude that no alien life forms exist in the universe. d) Since no life forms have been detected, there is a 50% chance that they do exist and 50% chance that they don't exist. e) They may exist. Science can produce a numerical estimate of the probability that they exist based upon observations.

Link To Solutions

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006

UW-Stout Geology and Soil Mechanics Review Quiz Section 10

Solutions

1. Which of the following best describes spectroscopic analysis? a) Identifying what wavelength of light an object is emitting gives us information about its chemical composition. b) Identifying what wavelength of light an object is emitting gives us information about the distance that object is away from us. c) Identifying what wavelength of light an object is emitting gives us information about how to image the object. d) Telescopes don't need to image planets in visible light. They can also use non-visible light to image objects.

2. Earth is the only object in our solar system that has ever had liquid water on its surface. a) True b) False

3. Deflation in a desert area is a process that involves a) abrasion. b) accumulation of ventifacts. c) sand dune collapse. d) movement of unconsolidated materials. e) none of the above.

4. The source of energy for the Sun is __________. a) nuclear fusion. b) nuclear fission. c) solar rays. d) plasma emissions.

5. Sand dunes that are parabolic shaped and have their points directed downwind are called _________ dunes. a) barchan b) longitudinal c) transverse d) star

6. Desert pavement can best be described as a) an accumulation of sand and silt particles, thus burying the larger rocks. b) an erosion of larger rocks producing large amounts of sand and silt. c) wind erosion blowing away all the small particles leaving the larger rocks. d) playa lake beds that have dried up and hardened.

7. The planet Venus has a very hot and thin atmosphere. Such that, it is hot enough to melt lead and has 7/1000 the earth's pressure. a) True b) False

8. Pluto can best be classified as what type of planet? a) Vulcan b) Terrestrial c) Jovian d) Martian

9. Which of the following statements best describes desertification? a) Due to natural processes, the land surrounding a desert slowly evolves into the desert. b) Due to changes in global wind patterns, some geographical areas can evolve into deserts. c) Due to changes in the earth's axis of rotation, some geographical areas can evolve into deserts. d) Improperly using the land surrounding deserts can contribute to the desert expanding geographically.

10. Intelligent alien life forms, from other planets outside our solar system, must exist. a) This statement is true according to the philosophy of science. b) This statement is false according to the philosophy of science. c) Since no life forms have been detected, one should conclude that no alien life forms exist in the universe. d) Since no life forms have been detected, there is a 50% chance that they do exist and 50% chance that they don't exist. e) They may exist. Science can produce a numerical estimate of the probability that they exist based upon observations.

For questions or comments regarding these pages contact Dr. Alan Scott / scotta@uwstout.edu / this page was last updated September 14, 2006