Geology and Earth Geology and Earth ResourcesResourcesBy: Michela GriffinBy: Michela Griffin

Earth as a Layered Earth as a Layered SphereSphere

CoreCore: Interior of the earth; composed of a dense, : Interior of the earth; composed of a dense, intensely hot mass of metal that is thousands of intensely hot mass of metal that is thousands of kilometers in diameter; contains metalkilometers in diameter; contains metal

Surrounding the core is the Surrounding the core is the mantlemantle: Less dense : Less dense than the core; contains oxygen, nitrogen, than the core; contains oxygen, nitrogen, magnesiummagnesium

Outermost layer of earth is the Outermost layer of earth is the crustcrust: cool, : cool, lightweight, outermost layer of the earth’s lightweight, outermost layer of the earth’s surface that floats on the soft underlying layers- surface that floats on the soft underlying layers- where the seafloor and continents arewhere the seafloor and continents are

Tectonic ProcessesTectonic ProcessesThe upper layer of the mantle has convection The upper layer of the mantle has convection currents that break the overlying crust in currents that break the overlying crust in huge blocks called huge blocks called Tectonic PlatesTectonic Plates: Huge : Huge blocks of the earth’s crust that slide around blocks of the earth’s crust that slide around slowly, pulling apart (diverge) to open new slowly, pulling apart (diverge) to open new ocean basins or crashing into each other ocean basins or crashing into each other (converge) to create new, larger landmasses(converge) to create new, larger landmasses

When an oceanic plate collides with a When an oceanic plate collides with a continental landmass, the continental plate continental landmass, the continental plate will ride up over the seafloor. will ride up over the seafloor.

Continents drift togetherContinents drift together giant landmass giant landmass (i.e. Pangaea)(i.e. Pangaea)

Techtonic Processes (cont.)Techtonic Processes (cont.)

Earthquakes are caused by grinding and Earthquakes are caused by grinding and jerking as plates slide past each other or as jerking as plates slide past each other or as they converge or divergethey converge or diverge

Mountain ranges are pushed up at the Mountain ranges are pushed up at the margins of colliding plates (i.e. Himalayas- margins of colliding plates (i.e. Himalayas- Indian subcontinent into Asia)Indian subcontinent into Asia)

Speed of processes vary- 1cm a year to Speed of processes vary- 1cm a year to 18cm a year18cm a year

Rocks and MineralsRocks and Minerals

MineralMineral: naturally occurring, inorganic, solid : naturally occurring, inorganic, solid element or composed with a definite element or composed with a definite chemical composition and a regular internal chemical composition and a regular internal crystal structurecrystal structure

Most fundamental characteristics: 1) Chemical Most fundamental characteristics: 1) Chemical Composition and 2) Crystal StructureComposition and 2) Crystal Structure

No 2 Minerals are the sameNo 2 Minerals are the same

RockRock: solid, cohesive, aggregate of one or : solid, cohesive, aggregate of one or more mineralsmore minerals

The Rock CycleThe Rock CycleThe rock cycle includes a variety of geologic The rock cycle includes a variety of geologic processes that can transform any rockprocesses that can transform any rock

The Rock Cycle (cont.)The Rock Cycle (cont.)Three major rock classifications: Three major rock classifications: igneous, sedimentary, and metamorphicigneous, sedimentary, and metamorphic

Igneous Rocks: The most common rock Igneous Rocks: The most common rock type; made by cooling magma type; made by cooling magma

Sedimentary rock is formed from the long-Sedimentary rock is formed from the long-term deposit and compaction of sediments term deposit and compaction of sediments into rock.into rock.

Metamorphic rock is rock formed when Metamorphic rock is rock formed when another type of rock is changed by another type of rock is changed by pressure, heat, and tectonic processes. pressure, heat, and tectonic processes. (i.e. limestone (i.e. limestone marble) marble)

IGNEOUS ROCKIGNEOUS ROCK METAMORPHIC METAMORPHIC ROCKROCK

SEDIMENTARY SEDIMENTARY ROCKROCK

WeatheringWeathering

Mechanical weathering is the physical Mechanical weathering is the physical breakup of rocks into smaller pieces breakup of rocks into smaller pieces without changing the chemical without changing the chemical composition.composition.

Chemical weathering is the selective Chemical weathering is the selective removal or alteration of specific removal or alteration of specific components that leads to weakening components that leads to weakening and disintegration of the rockand disintegration of the rock

Economic Geology and Economic Geology and Mineralogy Mineralogy

Economic geology is the study of Economic geology is the study of minerals that are heavily used in minerals that are heavily used in manufacturing and an important part of manufacturing and an important part of commerce.commerce.

Metals have been very important in human Metals have been very important in human affairs (i.e. Stone Age)affairs (i.e. Stone Age)

Most economically valuable resources exist Most economically valuable resources exist everywhere in small amountseverywhere in small amounts

Economic geology is the study of Economic geology is the study of minerals that are heavily used in minerals that are heavily used in manufacturing and an important part of manufacturing and an important part of commerce.commerce.

Metals have been very important in human Metals have been very important in human affairs (i.e. Stone Age)affairs (i.e. Stone Age)

Most economically valuable resources exist Most economically valuable resources exist everywhere in small amountseverywhere in small amounts

Metals & Metals & NonmetalsNonmetals

Metals consumed in greatest quantity: Metals consumed in greatest quantity: iron, aluminum, manganese, copper and iron, aluminum, manganese, copper and chromium- produced mainly in chromium- produced mainly in mountainous areasmountainous areas

Nonmetals (covers silicate minerals to Nonmetals (covers silicate minerals to sand, gravel, salts, etc.): durable, sand, gravel, salts, etc.): durable, highly valuable, and easily portablehighly valuable, and easily portable

i.e. Gemstonesi.e. GemstonesSand and gravel production comprise by Sand and gravel production comprise by far the greatest volume and dollar value far the greatest volume and dollar value of all nonmetal mineral resources. of all nonmetal mineral resources.

Environmental Effects Environmental Effects of Resource Extractionof Resource ExtractionMining and purifying all of the mineral Mining and purifying all of the mineral resources can have severe resources can have severe environmental and social consequencesenvironmental and social consequences

Can affect water quality: i.e. sulfuric acid Can affect water quality: i.e. sulfuric acid is produced when gold and other metals is produced when gold and other metals are mined from sulfide ores- DANGEROUSare mined from sulfide ores- DANGEROUS

Chemical substances can contaminate Chemical substances can contaminate lakes and streamslakes and streams

MiningMiningPlacer mining- washing out metals deposited in the gravel of streambeds (i.e. gold) destroys streambeds but fills the water with suspended solids that smother aquatic life

Other types of mining: open-pit mining, strip mining, and underground mining

Risk of fires: inaccessibility and size of the fires make many impossible to extinguish and control

‘Toxic Soup’ in metal mines can leak into lakes and endanger wildlife- 12,000 miles of rivers and streams in the U.S. are contaminated by mine drainage

1997 federal Surface Mining Control and Reclamation Act requires better restoration of strip-mined lands; but restoration is difficult because it is expensive

Processing OresProcessing Ores

Metals are extracted from ores by heating or Metals are extracted from ores by heating or with chemical solvents- releases large with chemical solvents- releases large quantities of toxic materialsquantities of toxic materials

SmeltingSmelting: roasting ore to release metals; : roasting ore to release metals; major source of air pollutionmajor source of air pollution

Heap-Leach ExtractionHeap-Leach Extraction: piling crushed ore : piling crushed ore in huge heaps and spraying it with a dilute in huge heaps and spraying it with a dilute alakine-cyanide solution; large water alakine-cyanide solution; large water pollutantpollutant

Conserving Geologic ResourcesConserving Geologic Resources

RecyclingRecyclingMetals are easily recyclable and Metals are easily recyclable and require much less energy than require much less energy than extracting new metals (i.e. Aluminum)extracting new metals (i.e. Aluminum)

New materials can be substituted New materials can be substituted for oldfor old

Using iron and steel replaced by Using iron and steel replaced by polymers, aluminum, etc.polymers, aluminum, etc.

Geologic HazardsGeologic Hazards

Earthquakes, volcanic eruptions, floods, and Earthquakes, volcanic eruptions, floods, and landslides and other catastrophic events, landslides and other catastrophic events, though rare, have shaped the earth though rare, have shaped the earth significantly significantly

Earthquakes can be very Earthquakes can be very destructivedestructive

EarthquakesEarthquakes are sudden movements in the are sudden movements in the earth’s crust that occur along faults where one earth’s crust that occur along faults where one rock mass slides past another onerock mass slides past another one

‘‘Mysterious, sudden, and violent’Mysterious, sudden, and violent’Worst death toll occurs in cities with poorly Worst death toll occurs in cities with poorly constructed buildingsconstructed buildingsMost seismically active region in the U.S. is along Most seismically active region in the U.S. is along the west coast where tectonic plates are collidingthe west coast where tectonic plates are colliding

Tsunamis are giant seismic sea swells generated Tsunamis are giant seismic sea swells generated from the center of an earthquake. They are from the center of an earthquake. They are incredibly destructive to coastal areas.incredibly destructive to coastal areas.

VolcanoesVolcanoesVolcanoes and undersea magma vents produce much Volcanoes and undersea magma vents produce much of the earth’s crust but release large volumes of ash of the earth’s crust but release large volumes of ash and dust into the airand dust into the air can block sunlight can block sunlight

““Ring of Fire”- Ring of Fire”- seismic activity and active volcanoes seismic activity and active volcanoes around the edge of the Pacific Oceanaround the edge of the Pacific Ocean

More than 500 million people live in the danger zone More than 500 million people live in the danger zone around volcanoesaround volcanoes

Nuees ardentes (glowing clouds) are deadly, denser Nuees ardentes (glowing clouds) are deadly, denser than air mixtures of hot gases and ash like those that than air mixtures of hot gases and ash like those that inundated Pompeiiinundated Pompeii

Mudslides are also dangerousMudslides are also dangerous

LandslidesLandslidesMass wastingMass wasting: geological materials are : geological materials are moved down slope from one place to anothermoved down slope from one place to another

i.e. Rockslides and avalanchesi.e. Rockslides and avalanches

Over $1 billion in property damage is done Over $1 billion in property damage is done every year by landslides in the U.S.every year by landslides in the U.S.

Many human activities such as road Many human activities such as road construction and forest clearing increase construction and forest clearing increase the frequency and damage done by the frequency and damage done by landslides landslides

Works CitedWorks Citedhttp://martianchronicles.files.wordpress.com/http://martianchronicles.files.wordpress.com/2008/08/103949main_earth10.jpg2008/08/103949main_earth10.jpg

http://www.earth.northwestern.edu/people/seth/B02/http://www.earth.northwestern.edu/people/seth/B02/nasa_plate_map.jpgnasa_plate_map.jpg

http://www.matt-willard.com/artwork/design/Rock-Cycle.jpghttp://www.matt-willard.com/artwork/design/Rock-Cycle.jpg

Montgomery, C. W. 1997. Montgomery, C. W. 1997. Environmental GeologyEnvironmental Geology (4(4thth ed.) ed.). Dubuque, . Dubuque, IA: WCB/McGraw-Hill Co. IA: WCB/McGraw-Hill Co.

Plummer, C. C., et al. 1999. Plummer, C. C., et al. 1999. Physical GeologyPhysical Geology. Dubuque, IA: . Dubuque, IA: WCB/McGraw-Hill Co. WCB/McGraw-Hill Co.

Ripley, E. A., et al. 1996. Ripley, E. A., et al. 1996. Environmental Effects of Mining.Environmental Effects of Mining. Delray Delray Beach, FL: St. Lucie Press. Beach, FL: St. Lucie Press.

http://www.mysciencebox.org/files/images/Rocks.JPGhttp://www.mysciencebox.org/files/images/Rocks.JPG

http://www.fcgov.com/oem/oem-images/earthquake-map.gifhttp://www.fcgov.com/oem/oem-images/earthquake-map.gif

http://www.mhhe.com/biosci/pae/environmentalscience/http://www.mhhe.com/biosci/pae/environmentalscience/cunningham6/student/olc/references_16.mhtmlcunningham6/student/olc/references_16.mhtml