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Prom/se Summer 2006Science Institute

Earth Science LiteracyFacilitator Guide-Middle School

SUMMER 2006 SCIENCE INSTITUTE

EARTH SCIENCE LITERACY MIDDLE SCHOOL EARTH SCIENCE

TABLE OF CONTENTSCourse Goals 2Standards Addressed 5Experience-Patterns-Explanations (EPE) 7General Overview of the Course 9Daily Agenda 10Course Materials List 11Day 1 13Activity 1.1 13Activity 1.2 14Activity 1.3 14Activity 1.4 19Activity 1.5 31Activity 1.6 33Activity 1.7 37Day 2 39Activity 2.1 39Activity 2.2 39Activity 2.3 43Activity 2.4 50Activity 2.5 53Activity 2.6 53Day 3 54Activity 3.1 54Activity 3.2 56Activity 3.3 59Activity 3.4 61Day 4 62Activity 4.1 & 4.2 62Activity 4.3 64Activity 4.4 73

Copyright 2006 MSU PROM/SE Supported by the National Science Foundation Agreement No. EHR-0314866 www.promse.msu.edu 1

http://www.promse.msu.edu/

SUMMER 2006 SCIENCE INSTITUTE

EARTH SCIENCE LITERACY MIDDLE SCHOOL EARTH SCIENCE

Goals for the CourseBig Idea: The Earth is constantly changing and the evidence for these changes is recorded in the rocks of the Earth’s surface. Sea levels rise and fall, mountains are uplifted and eroded, and glaciers wax and wane. These changes are the result of interactions between two Earth systems: the geosphere and the hydrosphere. There are many processes responsible for change, including erosion and deposition, powered by the hydrosphere and gravity; and tectonic uplift, powered by the Earth’s internal heat. These processes operate at different rates and across different timescales.

Driving Question(s): Marine invertebrate fossils found over much of the US Midwest indicate that from about 540 to 320 million years ago, this area was covered by a shallow, tropical sea. How did this region change from a marine environment to the terrestrial environment with which we are familiar today, and what is the evidence for these changes?

Desired Response: Over the past 500 million years, this area experienced several significant changes. Abundant fossils of animals known to have lived exclusively in marine environments indicate that during the early part of this history Michigan and Ohio were covered by a shallow, tropical sea. The vertical sequence of sedimentary rocks, particularly sandstone, shale, and limestone, record multiple fluctuations in sea level (transgression/regression) during this time. Limestone is deposited in clear water and is indicative of maximum transgression. Shale and sandstone derive from renewed sediment influx from an uplifted source area, and are associated with sea-level fall, or regression. Correlation of stratigraphic columns from east-to-west- across Ohio to Pennsylvania show thickening of the sandstones toward the east, indicating that the source area lie in that direction. The sediments become increasingly compositionally and texturally less mature toward the east, also indicating a source area in that direction. By approximately 300 million years ago, the shallow cratonic seas regressed from this part of North America for the last time. Marine limestone deposition was replaced by sandstone, shale, and coal deposition from coastal, swamp, and fluvial (river) environments.

The regression of the seas and the deposition of poorly-sorted, coarse-grained sediments are evidence for tectonic uplift. That the sediments thicken to the east indicates that there was significant uplift (source area) to the east. This uplift was associated with tectonic activity, specifically, the convergence and eventual collision between North America and Africa, during the Paleozoic Era. By the Mesozoic (250 million years ago), the region was uplifted above sea



level and erosional processes dominated. As a result, there is little record of the Mesozoic recorded in the Michigan/Ohio region.

Finally, during the Cenozoic, glaciers advanced multiple times from glacial centers to the north, carving out the Great Lakes and depositing large volumes of sand and gravel responsible for the surface topography we see today.

Connection to Unifying Theme - SystemsThis course addresses many of the aspects identified in the NRC National Science Education Standards (NSES) for developing an understanding of the structure of the Earth system. The Earth consists of four interacting systems (geosphere, hydrosphere, atmosphere, biosphere). This course emphasizes the organization of the geosphere and the processes responsible for change on the Earth’s crust. The course also addresses the interaction between the geosphere and the hydrosphere (sea level rise & fall, stream processes), and the biosphere (the geosphere as a constraint on what life forms can exist at certain times). Teachers will investigate how these processes act and systems interact over a range of time scales and distance scales.

Connection to Unifying Principle – EnergyThis course will provide teachers with an opportunity to investigate energy in Earth systems by exploring the relationship between energy and sediment sorting in aqueous environments. Teachers will investigate the sources of energy responsible for erosion and deposition (gravitational and solar) and tectonic uplift (internal energy from radioactive isotope decay).

Main Ideas (Knowing Statement)1. The geologic time scale is a chronologic arrangement of geologic events over very long

periods of time. 2. Fossils hold clues to past life and environments 3. Rocks provide evidence for past environments and successive changes over time.4. Water erodes, transports, sorts and deposits sediment

A. Fine grained material is deposited farther from its source than coarse-grained materials. Shales are deposited in quiet water, sandstones are deposited in high-energy, near shore environments. Coarse grained, poorly sorted material is deposited by rivers close to the source, or by glacial ice.

B. Limestone is precipitated from sea water, either organically or inorganically.5. Walther’s Law – vertical succession of sedimentary facies mirrors horizontal relationships

over time. Vertical columns (stratigraphic columns) record laterally migrating environments due to sea level rise and fall.

6. Stratigraphic columns can be correlated to build a coherent picture of changes over large areas and time.

7. Tectonic uplift is responsible for sea level changes, sediment erosion and depositional patterns. A. The tectonic uplift responsible for the changes seen in MI and OH are related to rise of

the Appalachian mountains caused by a continent-continent collision between North America and Africa

8. Cycles of glacial advances and retreats during the Pleistocene are responsible for current topography and surface geology.



Objectives (Doing Statements)Teachers will be able to:1. Explain the Earth processes responsible for changes in Ohio/Michigan over the past 500

million years.A. Use data from fossils and rock samples to identify what has changed in Ohio/Michigan.B. Correlate stratigraphic columns to construct a cross-section across Ohio/Michigan. C. Use the cross-section to construct a chronology of changes in Ohio/Michigan.D. Describe the processes responsible for the changes evident from rocks, fossils, and cross-

sections/maps.E. Locate the major changes on a geologic time line and mark the time across which various

processes were operating to produce those changes2. Constructing Objectives (From Michigan Curriculum Framework)

A. Generate scientific questions about the world based on observation.B. Design and conduct scientific investigations.C. Use tools and equipment appropriate to scientific investigations.D. Use metric measurement devices to provide consistency in an investigation.E. Use sources of information in support of scientific investigations.F. Write and follow procedures in the form of step-by-step instructions, formulas, flow

diagrams, and sketches.3. Reflecting Objectives (From Michigan Curriculum Framework)

A. Evaluate the strengths and weaknesses of claims, arguments, or data.B. Describe limitations in personal knowledge.C. Show how common themes of science, mathematics, and technology apply in real-world

contexts.D. Develop an awareness of and sensitivity to the natural world.



Standards Addressed: History of the Earth

NSES AAAS MCF OhioNSES ES 5-8 Earth’s History p. 1601. The Earth processes we see today, including erosion, movement of lithospheric plates, and changes in atmospheric composition are similar to those that occurred in the past. Earth history is also influenced by occasional catastrophes, such as the impact of an asteroid or comet.

EG.V.1 MS Geosphere p. 1124. Explain how rocks and fossils are used to understand the age and geological history of the earth.Key concepts: Fossils, extinct plants and animals, ages of fossils, rock layers, timelines, relative dating.Real-world contexts: Fossils found in gravel, mines and quarries, museum displays; places where rock layers are visible, such as Pictured Rocks, quarries, Grand Canyon, road cuts; Michigan fossils, such as trilobites, brachiopods, Petosky stones; specific examples of extinct plants and animals, such as dinosaurs.

Explain the 4.5-billion-year history of Earth and the 4 billion-year-history of life on Earth based on observable scientific evidence in the geologic record.

NSES ES 5-8 Earth’s History p. 1602. Fossils provide important evidence of how life and environmental conditions have changed.

Processes that Shape the EarthNSES AAAS MCF Ohio

NSES ES 5-8 Structure of the Earth System p. 1603. Land forms are the result of a combination of constructive and destructive forces. Constructive forces include crustal deformation, volcanic eruption and deposition of sediment, while destructive forces include weathering and erosion.

4c Processes that Shape the Earth p. 731. The interior of the Earth is hot. Heat flow and movement of materials within the Earth cause earthquakes and volcanic eruptions and create mountains and ocean basins. Gas and dust from large volcanoes can change the atmosphere.

EG.V.1 MS Geosphere p. 1121. Describe and identify surface features using maps.Key concepts: Landforms—plains, deserts, plateaus, basin, Great Lakes, rivers, continental divide, mountains, mountain range, or mountain chain.Tools: Maps—relief, topographic, elevation.Real-world contexts: Maps showing continental and regional surface features, such as the Great Lakes or local topography.

Describe the processes that contribute to the continuous changing of Earth's surface (e.g., earthquakes, volcanic eruptions, erosion, mountain building and lithospheric plate movements).




4c Processes that Shape the Earth p. 732. Some changes in the Earth’s surface are abrupt (such as earthquakes and volcanic eruptions), while other changes happen very slowly (such as uplift and wearing down of mountains). The Earth’s surface is shaped in part by the motion of water and wind over very long times, which act to level mountain ranges.

EG.V.1 MS Geosphere p. 1122. Explain how rocks are formed.Key concepts: Rock cycle processes—melting and cooling (igneous rocks); heat and pressure (metamorphic rocks); cementing and crystallization of sediments (sedimentary rocks). Minerals. Heat source is interior of earth. Materials—silt, clay, gravel, sand, rock, lava, magma, remains of living things (bones, shells, plants). Real-world contexts: Physical environments where rocks are being formed: volcanoes; depositional environments, such as ocean floor, deltas, beaches, swamps; metamorphic environments deep within the earth’s crust.

Identify that the lithosphere contains rocks and minerals and that minerals make up rocks. Describe how rocks and minerals are formed and/or classified

4c Processes that Shape the Earth p. 733. Sediments of sand and smaller particles (sometimes containing the remains of organisms) are gradually buried and are cemented together by dissolved minerals for form solid rock again.

EG.V.1 MS Geosphere p. 1123. Explain how rocks are broken down, how soil is formed and how surface features change. Key concepts: Chemical and mechanical weathering; erosion by glaciers, water, wind and downslope movement; decomposition, humus.Real-world contexts: Regions in Michigan where erosion by wind, water, or glaciers may have occurred, such as river valleys, gullies, shoreline of Great Lakes; chemical weathering from acid rain, formation of caves, caverns and sink holes; physical weathering, frost action such as potholes and cracks in sidewalks; plant roots by bacteria, fungi, worms, rodents, other animals.

Describe the interactions of matter and energy throughout the lithosphere, hydrosphere, and atmosphere (e.g. water cycle, weather and pollution).




4c Processes that Shape the Earth p. 735. Thousands of layers of sedimentary rocks confirm the long history of the changing surface of the Earth and the changing life forms whose remains are found in successive layers. The youngest layers are not always found on top, because of folding, breaking and uplift of layers.

FRAMEWORK: Experience-Patterns-Explanations (EPE)EPE TableExperiences Patterns Explanations Examine fossils to

see what organisms used to live here and determine their environments

Examine rocks to determine environments of formation.

Draw and interpret maps, stratigraphic columns, and cross-sections.

Place events/changes on geologic time line.

Explore stream table to understand how water transports and sorts materials

Explore settling tank to see how water sorts materials.

Interpret animations of plate movements

Identify glacial advances and retreats from maps

The landscape & environments we see today have not always been this way.

Water erodes, transports sorts & deposits sediments in predictable patterns

Walther’s law

The Earth is constantly changing. Processes of uplift, erosion, deposition, and sea level rise are a few of the processes that are responsible for change.

Inquiry Application



Common Misconceptions Research in alternative conceptions in geology is thin. 1. Time – People do not really have misconceptions about what time is, but they have

incomplete conceptions of geologic time, chronologic order, and significance of certain geologic events. Children think of time in two categories (more ancient and less ancient). Adults have three categories (extremely ancient, moderately ancient, and less ancient). (Ault, 1982; Trend, 1998, 2000, 2001).

2. Plate Tectonics & Mountain Building – A. Mountains are formed from wind deposition or underground pressure. (Chang &

Barufaldi, 1999)B. Old mountains are tall and young mountains are small because mountains grow, like

trees. (J. C. Libarkin et al., 2003)C. “Geologic States” (J. Libarkin, 2006)

3. Rocks – Few children can relate rocks to the processes that formed them. (Driver et al., 1994)

Ault, C. R., Jr. (1982). Time in geological explanations as perceived by elementary-school students. Journal of Geological Education, 30, 304-309.

Chang, C.-Y., & Barufaldi, J. P. (1999). The use of problem-solving-based instructional model in initiating change in students' achievement and alternative framework. International Journal of Science Education, 21, 373-388.

Driver, R., Squires, A., Rushworth, P., & Wood-Robinson, V. (1994). Making sense of secondary science: Research into children's ideas. New York: Routledge.

Libarkin, J. (2006). Magnetic continents and other conundrums: Innovative approaches to analyzing student conceptions about the earth, MSU Job Talk. East Lansing, MI.

Libarkin, J. C., Beilfuss, M., & Kurdziel, J. P. (2003). Student cognition about earth systems. Paper presented at the National Association for Research in Science Teaching, Philadelphia, PA.

Trend, R. D. (1998). An investigation into understanding of geological time among 10-and 11-year-old children. International Journal of Science Education, 20(8), 973-988.

Trend, R. D. (2000). Conceptions of geological time among primary teacher trainees, with reference to their engagement with geoscience, history, and science. International Journal of Science Education, 22(5), 539-555.

Trend, R. D. (2001). Deep time framework: A preliminary study of U.K. Primary teachers' conceptions of geological time and perceptions of geoscience. Journal of Research in Science Teaching, 38(2), 191-221.



General Overview of the Course:

Guidelines for all Prom/se course timeframes: Institute days start at 8:30 and end at 4:00 Lunch will be one hour, starting between 11:30 and 12:15 pm. Monday will begin as a whole group for the first hour. The teachers will move into the

courses starting at 9:45. Monday through Wednesday the class will end at 3:15. At 3:30 the teachers will meet as

a whole group sitting by district to discuss what they learned that day and consider how the concepts are connecting across the courses.

On Thursday, the courses will end at noon. This means the course Post-assessment must be completed before breaking at noon. After lunch, the teachers will meet as a whole group sitting by district to discuss what they learned that day and consider how the concepts are connecting across the courses. They will have time at the end to share out and have whole group discussion. A whole group institute post-assessment will be administered during the last hour.

“Gots and Needs”--A chart will be provided in each room, divided in half , and labeled one half "GOTS" and the other half "NEEDS". During the session, teachers write onto a sticky note (one thought per note) what they are getting during the day and what they still need. "Gots" could be anything they gain or get from the session. This may include something new they learned, a new friend they met, a new strategy, and so forth. "Needs" can be questions that arise, physical needs (e.g., the room is too cold), areas they would like more information about, or other needs that develop.

“Parking Lot”--The parking lot serves as a space where participants can post thoughts and concerns (problems, issues, concerns, ideas) that you don’t want to lose, but will redirect the session if addressed at the time it is raised. You can revisit these at the end/beginning of the day or where the topic better fits in the sequence. This can be pre-set as a piece of chart paper in the back of the room. The chart and sticky notes will be provided in each room for this use, identified as “Parking Lot”.



AGENDA FOR EARTH SCIENCE COURSE:MONDAY Day 1 Focus: Introduction, developing geologic time framework, establishing problem, exploring data9:45-11:00 1.1 Introduction to course, class, facilitators

1.2 Engage: Pre-Assess and discuss course focus11:00-11:30 1.3 Engage: State fossil activity11:30-12:30 Lunch12:30-1:30 1.4 Engage and Explore: Constructing a geologic timeline1:30-2:15 1.5 Explore and Elaborate: Mapping fossil distribution on a state county

map2:15-3:00 1.6 Explore: Sediment Exploration (start)3:00-3:15 1.7 Explain: DiscussionHomework: Elaborate & Evaluate: daily write-up (what did you gain, what questions

do you have?)

TUESDAY Day 2 Focus: Scaling up: From sediments to facies to depositional environments 8:30-9:30 2.1 Explore & Explain: Wrap-up Sediment exploration exercise 9:30-11:30 2.2a-c- Explore & Explain: Stream table/settling tube exercise

2.2d Explain & Elaborate: Sediments-environments & processes (facies)1l:30-12:30 Lunch12:30-2:00 2.3 Explore & Explain: Facies maps2:00-3:00 2.4 Elaborate: From lateral to vertical relationships: Stratigraphic

Columns3:00-3:15 2.5 Explain, Elaborate, Evaluate: Sharing and DiscussionHomework: 2.6 Elaborate & Evaluate: daily write-up (what did you gain, what

questions do you have?)

WEDNESDAY Day 3 Focus: Experience and application in the field; integration over time8:30-12:00 3.1 Engage, Explore, Elaborate: Field experience12:00-1:00 Lunch1:00-2:30 3.2 Explore & Explain: Correlation 2:30-3:00 3.3 Explain & Elaborate: Time line integration3:00-3:15 3.4 Explain, Elaborate, Evaluate: Sharing and discussionHomework: Elaborate & Evaluate: daily write-up (what did you gain, what questions

do you have?)

THURSDAY Day 4 Focus: Driving forces—energy for change8:30-9:00 4.1 Engage: the day ahead, context9:00-10:00 4.2 Explore: Computer lab—tectonic processes 10:00-11:30 4.3 Explore: Glacial processes & pulling it all together11:30-12:00 4.4 Explain: Post-Assessment



Course Materials List: Materials Number needed

Golden Guide Fossil ID book 1 book for every 2 participantsFossils of Ohio (edited by Feldmann) - Ohio Dept. of Natural Resources Bulletin 70

1

Old Bedrock Geology of Ohio - Poster Size 1Surface geology of Ohio - Poster Size 1Ohio Shaded Bedrock Topographic Map - Poster Size

1

Michigan Bedrock Geology Map - Poster Size 1Michigan Surface Geology Map - Poster Size 1Michigan Fossils Poster 1US Tapestry of Time Map 1Great Lakes Geologic Highway Map 1Hand lenses 1 for each participantColored pencils 1 set/participantCash register tape 15 (5 for each of 3 institutes)Measuring Tape 4 Meter sticksRulers (metric)Scotch tapeClipboards

4 1 per participant6 (2 rolls for each institute)1 per participant

Scissors 1 per classArkose student samples 1 bag (10/bag)Arkose hand sample 1Conglomerate student samples 1 bag (10/bag)Conglomerate hand samples 1Mature sandstone student samples 1 bag (10/bag)Mature sandstone hand samples 1shale student samples 1 bag (10/bag)shale hand samples 1limestone student samples 1 bag (10/bag)limestone hand samples 1Sand Set 1 setIsotelus maximus (Ohio State Fossil - trilobite) 1Michigan Fossil Set 1 set for every 4 participantsSediment Comparators 1 for every participantbinocular microscopes 4 /classComplete Economy Stream Table 1/classsediment for stream table 3Sedimentator (settling tube) 1 for every 4 participantsplastic buckets 2PALEOMAP software 1 for every 2 teachers

OtherVans or buses for field tripaccess to computer lab (PC) 1 computer/2 teachers

Assessment Strategies:



Pretest & Post-test-- Multiple format assessment. Multiple choice and short-answer questions about basic principles and concepts.

Formative--Detailed instructions to facilitators for embedded assessments are identified for each activity. Each teacher will write daily about what they learned and questions they still have.

Advance Preparation Notes:

Familiarize yourself with the conference facility, location of restrooms, lunch procedure, classroom technology.

If possible, scout the field excursion site (Day 3 activity) in advance of the activity.

Read through the Facilitator’s Guide and the Activity Guide.

Check that all materials (see materials list, above) are available for each activity.

Prepare “Gots and Needs” and “Parking lot” areas for participant input (see explanation of these two tools under “General overview of the course”, above)



DAY 1ACTIVITY #1.1: Introductions

Purpose and Goals of the activity: To establish working relationships between course participants; to informally collect information on backgrounds of participants, perceived needs and wants of the participants. Goal: for participants to learn each other’s names, to establish common ground between participants.

Estimated time to complete the activity: 15 minutesDetailed procedure: Facilitator introduces self and invites participants to introduce themselves

(perhaps by giving their name, school, grade taught, and a statement of what they hope to take away from this experience). Introduce the “Gots and Needs” and “Parking Lot” tools:“Gots and Needs”--A chart, divided in half , labeled "GOTS" "NEEDS". During the session, participants write onto a sticky note (one thought per note)

what they are getting during the day and what they still need. "Gots" could be anything they gain from the session. This may include something new they learned, a new friend they met, a new strategy, and so forth. "Needs" can be questions that arise, physical needs (e.g., the room is too cold), areas they would like more information about, or other needs that develop. “Parking Lot”--The parking lot serves as a space where participants can post thoughts and concerns (problems, issues, concerns, ideas) that you don’t want to lose, but will redirect the session if addressed at the time it is raised. You can revisit these at the end/beginning of the day or where the topic better fits in the sequence. The chart and sticky notes will be provided in each room for this use, identified as “Parking Lot”. Reviewing Norms: review a set of “norms” or expectations for the week. Some common

norms you will want to promote include: We will begin and end on time (includes breaks) Take care of your personal needs as needed (assumption is that they are

professionals) Participate- they who do the work do the learning! Ask questions- No question is a “dumb” question. Listen to others. Mute or turn off cell phones.

You will want to solicit other norms that the group expects or would like to list. Everyone should buy-into the norms.

REVIEW THE BINDER/MATERIALS: Walk the participants through the binder materials so they know what resources are provided and where to find them. This is also a good time to see if there are any general questions about the day and to review the agenda, if you have not already done so.

SAFETY CONSIDERATIONS: In this course the only safety considerations concern the field excursions (sun/heat protection). Please model effective classroom practice by reviewing and calling teachers attention to: http://www.nsta.org/main/pdfs/SafetyGuidelines.pdf



ACTIVITY #1.2: Pre-Course assessmentPurpose and Goals of the activity: to form the basis of comparison for the post-course

assessment.Estimated time to complete the activity: 1 hour, total: 30 minutes for the assessment; 30

minutes to discuss the assessmentMaterials list: copies of assessment for each participantDetailed procedure: 1. Facilitator hands out assessment, collects them at the end of 20 minutes (or some reasonable

amount of time depending on the dynamics of the particular group of participants). 2. Facilitators should lead a whole class discussion to

A. Identify areas of strengths.B. Identify areas of weakness.C. Identify questions.D. Use the assessment as a lead in to the overview of the course.

ACTIVITY #1.3: Directed Inquiry: State Fossil/symbol Investigation

Purpose and Goals of the activity: The purpose of this activity is to build on the current knowledge the participants have of their state symbols and construct a geologic history of the Great Lakes region one observation at a time to deepen their understanding of the millennia of changes represented by these fossils and the physical observations and tools geologists use to reconstruct these events.

Main “take home” message: These state symbols are evidence of dramatic change in North America from the distant geologic past to today, and are clues to the processes involved in that change.

Estimated time to complete the activity: 30 minutesMaterials list: Isotelus trilobite (Ohio)- 1 for class Petoskey stone (Michigan – included in Michigan fossil kit) – 1 per group of 4 teachers Michigan Fossil Kit - 1 per group of 4 Hand lenses – 1 per participant Golden Guide of Fossils – 1 per 2 participants Fossils of Ohio – 1 book for class Activity Sheet 1.3 – 1 per person (in Activity Guide)Advance preparation notes Facilitators should be able to identify the fossils in the Michigan fossil kit and be familiar

with the key features of each fossil, their ages, and the environments in which they lived. Read Background NotesSafety notes/considerations: noneOverview: Most participants will be familiar with Ohio’s state fossil and Michigan’s state stone,

but they may not be familiar with the organisms represented by the fossils or the environments in which these organisms lived, and the dramatic changes in the Michigan/Ohio environment represented by these fossils.



Background Notes: OH/MI StateFossils

I. Ohio State Fossil: IsotelusThe Ohio state fossil is Isotelus, a trilobite abundant in rocks of Ordovician age in southwestern

Ohio. Trilobites are an extinct class of arthropods, distantly related to Cheilcerates (horseshoe crabs, scorpions, and spiders) and Crustaceans (crabs, shrimp, and lobsters). Trilobites are unique among classes of arthropods because it is the only extinct class of arthropods. This fact is curious in light of the fact that trilobites were very successful by most measures of evolutionary success: geologically long-lived (from 530 million years ago to 260 million years ago), taxonomically diverse (more than 1500 genera have been described) morphologically very diverse, inhabiting different physical environments and ecological niches. Trilobites swam, floated, crawled, burrowed; they grubbed in the mud for organic detritus and actively sought out prey. They were smooth and sleek and ornately spiny. And they last inhabited the seas 230 million years ago. The explanation for their demise is unclear.

Classification: As a member of the Phylum Arthropoda, trilobites share the following characteristics with other members of the phylum: a segmented body, exoskeleton, jointed appendages, and growth through molting (periodic shedding of old exoskeleton). The classes of arthropods differ mainly in the number of main body segments and the number and type of appendages.

Ecology: Trilobites are found with other fossil organisms whose living relatives live in marine waters (brachiopods, crinoids, bryozoans) so trilobites are inferred to have been exclusively marine organisms. As mentioned above, the great morphological diversity of trilobites, and trace fossils attributable to the movement of trilobites over and through the sediment, suggest that they inhabited many different ecological niches.

Trilobite body plan: The name of the class (pronounced TRY-lo-bite) refers to the longitudinal (lengthwise) division of the trilobite's dorsal exoskeleton into a central lobe and two lateral lobes. Trilobites also have a three-part body plan head-to-tail (or anterior-to-posterior), comprising the headshield (cephalon), midsection (thorax), and "tail" (pygidium). [The trilobite exoskeleton or carapace is heavily calcified, perhaps more so than any modern arthropod, and we are left with an abundant, albeit often disarticulated, fossil record for the group.]

Cephalon : The head shield, or cephalon (from the Greek word for "head"--check this). Many trilobites have a differentiated central area, the glabella, outlined by glabellar furrows which define glabellar lobes. The glabella bordered on either side by the fixigenae (literally "fixed cheek"). In many trilobites a pair of facial sutures separate the fixigenae from the marginal librigenae (literally "free cheeks", as these are commonly released or freed during ecdysis). Some trilobites bear genal spines on the librigenae or fixigenae.

Eyes are the other prominent feature of the cephalon, and are variously developed in trilobites from large eyes with multiple, separate lenses (schizochroal) to smaller eyes with a single covering (holochrol), to presumably blind trilobites with no visible eyes.

Thorax: The cephalon is joined at its posterior edge with the segmented thorax. The medial axis of each thoracic segment is flanked by the lateral pleurae. The number of thoracic segments varies by species; some trilobites have as few as two, other have over 20. Each thoracic segment is articulated with its neighbors, enabling many trilobites to roll up, a providing protection for the vulnerable vental surface of the trilobite.



Pygidium: The thorax is joined posteriorly to a single fused tergite, the pygidium (plural, pygidia). The size, shape, and ornamentation (surface features) of pygidia vary widely. Some pygidia are little more than a single small tergite (micropygous); other pygidia are as large as the cephalon (isopygous); some appear segmented, but this is not a true segmentation reflecting segmentation in the body; others pygidia are smooth and featureless; still others may bear pygidial spines.

Ventral anatomy of trilobites: The ventral anatomy of most trilobites is poorly known. The vental surface carried the appendages and the mouth.

Trilobite appendages were apparently lightly scleritized compared to the dorsal exoskeleton and are only preserved in exceptional, fortuitous circumstances where trilobites were rapidly buried in an anoxic environment, which prevented decomposition of the delicate structures. Trilobites were long thought to be molluscs, akin to the chiton, crawling along the seafloor on a fleshy foot. The discovery of trilobites with appendages confirmed their arthropod affinity. Many trilobites apparently had a pair of appendages for each thoracic segment and a pair of antennae. In most trilobites for which appendages are known, the legs are undifferentiated, unspecialized, but the number of trilobites for which appendages are known is very small.

In many trilobites the mouth was directed backwards, and the animal passed food forward with its appendages. The single well-calcified (and thus, well-preserved) ventral tergite is the hypostome, which was essentially a mouthpart. The morphology of hypostomes is quite varied; some trilobites possessed small, thin plates, others, like Isotelus, had large, robust hypostoma. Trilobites also differ in the attachment of the hypostome to the ventral surface of the rostrum...

Preservation: Because of their jointed body design comprising separate articulated skeletal elements that became disarticulated after death and during molting, whole trilobites are rare as fossils. Trilobite exoskeletons were commony shed in separate pieces during molting (ecdysis). Arthropod math; 1 trilobite = numerous molted exoskeletons + 1 carcass. Thus, the vast majority of trilobite fossils are exuviae, the cast-off exoskeleton. The distinction between trilobite exuviae and carcasses is not always easy to make. Unlike many modern arthropods, trilobites did not resorb exoskeletal material before ecdysis, thus the exuviae are compositionally and structurally identical to the carcass. As with modern horseshoe crabs, sutures opened during ecdysis may close, and exuviae may be virtually indistinguishable from the carcass. Separation along facial sutures is a certain indication that the fossil is a molt, but sutures apparently did not open every time, and some fossils with intact sutures may be exuviae. Dislocations between major tergites (the cephalon and thorax; among thoracic segments; between the thorax and pygidium) are indicative of molts. Unnatural postures (sway-back thorax or a sharply down-tilted cephalon) are also characteristic of molts.



Carcasses are most reliably recognized by the presence of intact appendages, requiring exceptional circumstances for preservation.

The rarity of intact trilobites and the appeal of the design of their body plan make their fossil remains highly desired and prized.

II. Michigan State Rock: Petoskey StoneThe Petoskey Stone is actually a fossil coral, but it is not the state fossil of Michigan!

Petoskey Stones are officially designated as the state rock, and the title of Michigan state fossil was recently given to mastodons.

Classification: The Petoskey Stone is a member of an extinct Order of corals, the rugose, or horn corals, so named for the resemblance of some of these corals to animal horns. Petoskey corals are colonial, and each of the hexagonal corallites housed a single individual polyp. Corals belong to the Phylum Cnidaria or Coelenterata, and their close relatives include anemones, which are basically corals without the skeletal support. The phylum is distinguished by the presence of tentacles. The term coelenterate literally means “hollow gut” and the term cnidaria refers to the stinging cells characteristic of some member of the group. The Petoskey stone coral is most often referred to the genus Hexagonaria.

Anatomy: The calcareous skeleton, the corallum, is divided by vertical radial partitions, termed septa. In the aptly named Hexagonaria, the individual corallites are hexagonal in shape, giving the genus its distinctive “honeycomb” appearance.

Ecology: Modern corals are exclusively marine, and fossil corals are found in association with other groups known to be marine (brachiopods, bryozoans, cephalopods) so Petoskey stone corals are most reliably regarded as exclusively marine inhabitants. Petoskey stone corals are Devonian in age (416-359 million years old). Petosky Stones are found along Lake Michigan, in the “tip’ of Michigan’s lower peninsula, corresponding to the outcrop area of Devonian-age bedrock. (See geologic map of Michigan).

It is not known why rugose corals went extinct at the end of the Permian. There is an alternative suggestion that this Paleozoic group did not die out but that they evolved into the modern scleractinian corals. Petosky stones are most often mis-identified as fossil honeycombs because of their hexagonal corallites.

Detailed Procedure

1. Describe & Identify Fossils. 15 minutes Have participants work in group of 4 to describe and identify fossils in the Michigan fossil kit, using the Golden Guide and the Fossils of Ohio book to identify fossils. Everyone should describe and identify at least 3 fossils, one of which is the state fossil for their state, and record their descriptions on the State Fossil/Stone Investigation Sheet.



2. Whole Class Discussion about the fossils. 10 minutes. Facilitators should keep notes on the board or overhead projector. Participants should take notes on the discussion on their State Fossil/Stone Investigation Sheet. A. List 1. What do we know about the fossil?

Examples: what kind of animal it represents, what animal group it is most closely related to, whether this group is extinct, when the animal lived, where (geographically) the animal lived, naming parts of the animal, the kind of environment in which it lived (marine or fresh water? Tropical or temperate zones?), its ecologic/trophic niche, the name of the animal.

B. List 2. What can this fossil tell us?Examples: The environment has changed, plant and animal life has changed, etc.

C. List 3. What would we like to know?Examples: Why/how did it go extinct (climate change? Global warming or cooling? Plate tectonics?), what did it eat, etc. Sources we might use to find the answers to our questions

3. Synthesis discussion. 5 - 10 minutes. Draw out organizing questions on the workshop theme of Earth Change. Cull the List 3 to highlight questions that address the workshop’s objectives (e.g., Are these environments here now? What changed? How did it change? How did we get from what it was like when these fossils were alive to what it is like now?) Brainstorm: Hypothesize possible explanations & processes. Finish by explaining how this course will help us understand what changes took place, what processes were responsible for those changes, and the evidence for those changes.

Embedded Assessment Are participants making connection between the fossils and past environments? Are participants asking questions that indicate that they understand the interesting

problems that these fossils pose?MI & OH Benchmarks AddressedMichigan: EG.V.1 MS #4.- Explain how rocks and fossils are used to understand the age and

geological history of the earth.Ohio: Explain the 4.5-billion-year history of Earth and the 4 billion-year-history of life on Earth

based on observable scientific evidence in the geologic record.Systems & Energy – No connectionsElements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions.5E ModelEngage –

Activates prior knowledgeEstablishes a problem – What has changed?Elicits learner ideas

References:http://www.kgs.ku.edu/Extension/fossils/trilobite.html



Muller, Bruce, and Wilde, Wm., 2004, The complete guide to Petoskey stones. Ann Arbor, The University of Michigan Press.Ohio Geological Survey GEOFACTS sheet on Isotelus, the state FossilMichigan DEQ fact sheet on Petoskey Stones

ACTIVITY #1.4: Constructing a geologic time line to scale

Purpose and Goals of the activity: To gain an appreciation of time as a measure of change, so that physical and biological changes in the Earth can be used to mark the passage of time. The geologic timeline will provide the temporal framework within which to discuss Earth change, and the timeline will be referred to throughout the rest of the workshop. The purpose of this activity is to familiarize (or introduce) participants to the geologic time scale, and to gain an appreciation of the immensity of geologic time by constructing a scaled version of the history of the Earth from its formation 4.6 billion years ago to the present, with important physical and biological changes marked off along its length.

Main “take home” message: The distribution of the physical record of Earth change is not uniform; for example, 80% of Earth history is represented by rocks of the Precambrian Eon, yet the bulk of fossils are known from the last 20% of Earth history, the Phanerozoic Eon.

Estimated time to complete the activity: 1 hourMaterials list: Cash register tape – up to 5 rolls scissors – 1 pr for class Measuring tape -1 for class markers/pens/pencils scotch tape – 1 roll for class Activity Sheet 1.4 – 1 per person (in Activity Guide) List of significant biological/physical events and dates for each, to plot on timelineAdvance preparation notes Facilitators should be familiar with the geologic time scale and the directions for constructing

a geologic time scale from cash register tape. Read background notes, belowSafety notes/considerations: noneOverview: Following a discussion on “what is time?” participants will construct scaled

geologic timelines using a scale 1 m to 50 m.y. (= 92 meters) long, brainstorm a list of significant physical and biological Earth changes, then plot these events along the timeline. After all events are plotted, discussion of the non-uniform distribution of events (record of Earth change) along this timeline, and of possible reasons for this skew towards geologically younger events and processes.

Background Notes: Development of the Geologic Time Scale

One of the fundamental assumptions in geology is the Principle of Uniformitarianism which, simply stated, is that "the laws of nature do not change with time." This principle allows us to assume that the geological clock (record of changes in the Earth) worked the same 500 my ago as today.



Uniformitarianism is our fundamental assumption, and permits us to use our stratigraphic principles as tools to order geologic events, that is, to construct a relative chronology of earth history.

Time: What is the basic measure of time? [how do we know it exists? how do we measure it?] Invite discussion.

Answer: change. If nothing ever changed we would hav no sense of time (and probably, time would not exist?). Thus, changes--dynamism--record time. Many changes are recorded in rocks, so it's valid to look to rocks as geo-chronometers and to use rocks in detering the age of the earth, as well as for relative timing of different geologic events

Relative DatingDefinition: Relative dating--determining a relative chronologic order of a sequence of events. No quantitative or absolute numbers involved, based on fundamental stratigraphic principles for sedimentary strata that were first enunciated over 400 years ago (Nicholas Steno), including the principle of original horizontality, principle of superposition, principle of lateral continuity, principle of cross-cutting relations, principle of included fragments, and principle of faunal succession (attributed to British civil engineer and mapper Wm. Smith). [These principles are listed on a following page in a format for handout or over head transparency.]

The Geologic ColumnThe geologic column was developed using relative dating techniques, primarily the principle of superposition and faunal succession.

Early biostratigraphersFirst credited with dividing strata on the basis of fossils, Frenchman J.L. Giraud-Soularie

(1752-1813), in "A Natural History of Southern France," he divided limestone formations into 5 epochs, the strata of each characterized by a distinct assemblage of shells:

1st stage marked by fossils that have no living analogues [Primordial] 2nd age, intermediate: fossils of the 1st stage and some modern forms 3rd age: shells are all of recent form4th age: carbonaceous shales with plant material5th age: alluvium (unconsolidated)

Lavoisier (1742-1794), better known for contributions to chemistory, divided the Tertiary of the Paris Basin

Cuvier (1769-1832) and Brogniart, produced the first geologic map of the Paris Basin on the basis of faunal correlations.

Major divisions/nomenclatureFlow chart of Time Scale Hierarchy:

Eon [most inclusive]Era

PeriodEpoch [smallest slice of time]

This scale was developed largely in Europe in the mid 1800's. Names are taken from geographic features (towns, etc) where rocks of the age are well-exposed. The original subdivision of the geologic column was based on the wide-ranging, consistent recurring sequence of rock formations in the order they are found in Europe.



Note that this scale did not emerge fully formed and with unanimous consensus; there has been bitter argument over defining some boundaries (the story of Sedgwick and Murchison*).

The geologic time scale is a living document and continues to change; governed by the International Commission on Stratigraphy. Just last year (Fall ’05) the ISC ruled that the “Quaternary Period” did not merit separate consideration, and the Commission subsumed the Quaternary into the Neogene Period.:*Extra; the story of Sedgwick and MurchisonStratigraphic sequence of their time: "unstratified" rocks (igneous, metamorphic, cores of mt ranges) and stratified rocks divided in order of oldest to youngest: primary stratified rocks, transition, old red sandstone, oolitic, Cretaceous, tertiary, alluvium.

Adam Sedgwick (1785-1873), Englishman, worked on sequence in Wales and Scotland. Roderick Impey Murchison (1792-1871), mapping partner and friend for a while, but controversy over how to divide rocks between oldest known rocks (in UK) and "Old Red Sandstone" [Devonian], the "transition" rocks eventually destroyed their relationship.

Murchison started at the base of the "Old Red Sandstone" (Devonian) and worked stratigraphically downward and defined the Silurian. Together Sedgwick and Murchison described and named the Devonian System [1840]. Their criteria for defining rock systems included:

a system is a body of rock of separate and distinct lithologic characterits structural character is distinctit is faunally distinctit represents a distinct episode of the earth's history (=time)

i.e., they had lithologic, structural, and faunal criteria for definition

Sedgwick went to Wales and Scotland and started from the base, the oldest rocks closest to mt core, and worked upward. Both Sedgwick and Murchison agreed he was in odler rocks than Murchison's Silurian. In 1835 Sedgwick called these rocks "Cambrian". By this time Murchison realized that there was no major boundary or break or division between his Silurian in England and Sedgwick's Cambrian--the lowest Silurian beds passed laterally into uppermost Cambrian beds. This became a huge controversy, the Geological Survey could draw no definite line between the systems, the same fossils characterized both, and the Survey ruled that Sedgwick's Cambrian was actually Silurian [priority]. Murchison didn't mind, but Sedgwick did. Thus began hard feelings and estrangement. [books written on this topic, Geike's Life of Murchison, and a recent one by Rudwick]

Sedgwick eventually found an unconformable surface between "Upper Silurian" and everything below, and proposed that Cambrian should extend up to this break, thus subsuming Murchison's Lower Silurian. But, Murchison's fossil collections and nomenclature had priority.

Meanwhile, Barrande (1799-1883) found Silurian in Bohemia and below it a different, more primitive fauna, and established Sedgwick's Cambrian as a faunally distinctive unit.

Their dispute was ultimately settled posthumously. Lapworth proposed that Murchisons's Lower Silurian = Sedgwick's Upper Cambrian, and that this interval should be taken from both and separated as the Ordovician. The Ordovician was not accepted as a legitimate unit by the USGS unti 1904 (a caution to theses on the Ordovician--must look at literature on the Silurian). Thus, the Ordovician emerged as a compromise, although today major faunal turnover is recognized at that boundary from other sections.



BRITISH STRATIGRAPHIC COLUMN OF SEDGWICK AND MURCHISON'S DAY

YOUNGEST: AlluviumTertiaryCretaceousOoliticOld Red SandstoneTransition rocks

Primary stratified rocksOLDEST: Unstratified rocks (igneous, metamorphic)

SEDGWICK AND MURCHISON Applied "modern" criteria to defining rock systems:1. separate and distinct lithologic character2. distinct structural character3. distinct faunal character4. represents a distinct episode of earth history

i.e., they recognized the interpretive nature of stratigraphic unitsTogether defined DevonianMurchison defined SilurianSedgwick defined Cambrian

....parts of Silurian and Cambrian overlapped,eventually became the Ordovician

Geologic Time Scale Outline (pronunciation and symbols guide)Geologists always start with the oldest-to-youngest, so your notes will read upside-down.Precambrian [PC] an older term used to describe all rocks older than the Cambrian Period.

These are generally metamorphosed sedimentary rocks, metamorphic and igneous rx. Generally greatly deformed, very few fossils, primitive life forms.

More recent use divides the Precambrian into Three Eons: I. Hadean: from earliest Earth to 3.8 bybp, and no remaining rocks, “hellish” (hadean)

environment of volcanic eruptions, geothermal features, and impactsII. Archean: from 3.8 to 2.5 billion years ago; earliest evidence of life appears in these rocksIII. Proterozoic: from 2.5 bybp to 540 mybp; literally “before life”, a reference to the fact

that few body fossils are known from these rocks (although there are some)..All the rest of Earth’s history is part of the Phanerozoic (or “visible life”) Eon; the name

reflects the fact that well-preserved fossils appear at the beginning of this interval.

The Phanerozoic Eon is divided into 3 Eras: Paleozoic/Mesozoic/Cenozoic, and these names reflect the types of fossil lifeforms found in the rocks:

I. Paleozoic Era: "ancient life," fossils common, marine invertebrates, fish, amphibians. Divided into periods:



A. Cambrian [C], from Cambria, Latin word for Wales. These are the oldest, generally undeformed sediments resting on the deformed PC basement; first appearance of an abundant shelly fauna, the "age of trilobites".

B. Ordovician [O], from ancient Welsh tribe, Ordovics.C. Silurian [S], from a British tribe name, Silures [Dr. Who fans note the Silurians, a race in

that series]D. Devonian [D], from Devonshire, England; age of fishes E. Carboniferous [C], named for coal-bearing strata; in the US this Period is divided into two

periods, Mississippian [M], for upper Miss. valley, IA,ILPennsylvanian [|P], for Penn. coalF. Permian [P], for Perm, Russia, age of amphibians

II. Mesozoic era, "Middle Life", fossils not as primitiveA. Triassic [Tr], named for 3-fold division of rocks in GermanyB. Jurassic [J], named for Jura Mts of Eastern EuropeC. Cretaceous [K], from the Latin creta, "chalk", named for strata in England and France, e.g.,

the White Cliffs of Dover.III. Cenozoic Era, "Recent life", fossils closely related to modern life

Formerly, the Cenozoic was divided into the Tertiary and Quaternary Periods, a holdover from earlier time scales where Primary = Paleozoic; Secondary = Mesozoic. Today the Tertiary and Quaternary have been replaced by the Paleogene and Neogene Periods. These periods are divided into Epochs, something that dates back to Lyell (1828), who arranged all the Tertiary formations into 4 groups based on the ratio of extant:extinct fossils. These were the first formally defined epochs:

Pliocene--extant forms predominate [e.g., extant:extinct > 1]Miocene--extant species in minority

Eocene--small proportion of extnat species, extinct dominant [ratio <1]Now there are 7 Epochs of the Cenozoic Era recognized in North America: from oldest to youngest: Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene (or Recent or Modern).

Etymology of epochsPaleocene = old Eocene = primeval, dawn Oligocene = few, little Miocene = less Pliocene = more Pleistocene = much Holocene = whole, entire[Note: eras, periods are not equal in length]

With this nomenclature and scheme we enter a more modern stage of stratigraphy, weaned from the theoretical "primary, secondary, tertiary" to stratigraphic divisions based on observable features

(Faunal shifts). We are still left with a hodegepodge terminology, holdover from previous efforts, units named for the predominant mineralogy [Carboniferous, Cretaceous], other named for relative

position [Tertiary, Quaternary], other names based on geographic or cultural features. Little change or attempted change to clean it up [tradition is strong], but recent preference for Paleogene and Neogene to replace "Tertiary" [Paleogene comprising Paleocene, Eocene, and Oligocene; Neogene comprision

Miocene and Pliocene]



MNEMONIC DEVICES FOR GEOLOGIC TIME SCALE*

COLLEGE OFTEN STRESSES DAILY, CAUSING PROBLEMS THAT JUSTIFY COSIDERATIONS TO QUIT!

COLONEL OSCAR SAID, "DIE COURAGEOUS PRINCESS THEN JANE CAN TURN QUEEN"

CARS OVER SEAS DON'T CAUSE POLLUTION, THEY JUST COLLAPSE TOO QUICK.

COME ON, SALLY, DON'T CRY. PUT THIS JURY CASE TOGETHER QUICK! CARS OF SUPERIOR DESIGN CAN PUSH THE JAPANESE COMPANIES TO

QUIT.

*Note: these were constructed using “Carboniferous” instead of Mississippian and Pennsylvanian, and “Tertiary” and “Quaternary” instead of the more recent Paleogene and Neogene. Suggest students construct a mnemonic device using: C,O,S,D,M,P,P,T,J,K,P,N!

Fundamental Paradigms of Historical Geology:Uniformitarianism and Stratigraphic Principles

I. TimeDefinitions of time....

II. UniformitarianismJames Hutton (1726-1797), Scottish farmer/geologist, "Father of Historical Geology"

processes operate today as they did in the past we can use modern observations to interpret past conditions

"The present is the key to the past."“The laws of nature do not change.”

Note: not all processes that operated in the past still operate today

This does NOT violate uniformitarianism. processes may not operate at the same RATE as they did in the past

This does NOT violate uniformitarianism.

Uniformitarianism is fundamental to constructing a geologic "calendar" of events (time scale).



III. Early attempts at organizing Earth’s chronology

John Woodward [1665-1722]All rocks deposited as a result of the Flood:Top/youngest: chalk, unconsolidated sediments Bottom/oldest: heaviest rocks and fossils

Giraud-Soularie5th age: [youngest] unconsolidated alluvium4th age: carbonaceous shales (plant material)3rd age: shells of recent form2nd age: intermediate: fossils of 1st age and some modern forms1st stage [oldest]: fossils that have no living analogues

Two histories based on mountain ranges

I. Pierre Simon Pallas [1741-1811]Tertiary Mts.: low hills made of sandstoneSecondary Mts: fossiliferous limestonePrimitive Mountains: highest, granite, schists; older than the creation of living beings (unfossiliferous)

II. Johann Gottlob Lehmann [d. 1767]3rd order mts.: formed from time to time by local accident2nd order mts.: arose from an alteration of the ground “Flotzgebirge” [ore-bearing]; younger, stratified deposits, fossiliferous1st order mts: coeval with the formation of the world-—highest mts., structurally complex

First to use a 3-fold division: Giovanni Arduino [1713-1795] Tertiary: fossiliferous limestone, sandstone, clay; derived from the Secondary

Series Secondary: marine fossils, limestone, clay Primary: oldest, unfossiliferous, micaceous, strongly folded, schistose; found at

the cores of mountains(Note: volcanics treated separately!)



Two opposing philosophies:

I. Neptunist philosophy: Deposition from the primordial ocean

Abraham Gottlob Werner [1749-1817]

Alluvial Series: recent sand, clay, gravel, peat

Floetz rocks: part chemical, mostly mechanical, marking the continued ebb of the world ocean; sandstone, limestone, gypsum, halite, coal, basalt, obsidian, porphyry

Transitional Rocks: also “chemical” ppt., limestone, sandstone, but also containing “mechanical depositions” from the world’s oceans (and subsequent erosion of exposed rock)

Primitive: entirely of chemical origin, the oldest; granite, gneiss, slates, basalt

II. Plutonist philosophy: crystallization of rocks from original molten stateJames Hutton [1726-1797]

Secondary rocks: formed from primary rocks lithified by subterranean heat

Primary rocks: oldest rocks, schists, slates

SUMMARY/SYNTHESISEarly chronologies of Earth history are intimately linked with: one’s paradigm for how the Earth formed personal philosophy (e.g., reconciling religious doctrine with nature) personal experience/geography

All early workers recognized: Different rock types implied different events Materials of the Earth’s crust succeeded each other in a definite order (vs.

“thrown down at random”)i.e., the existence of basic stratigraphic principles



IV. Essential stratigraphic principles (Steno, Hutton, Smith)

1. Principle of superposition: in an undeformed sequence of sedimentary rocks, the oldest are at the bottom (deposited first)

2. Principle of original horizontality: sedimentary strata are originally deposited (more or less) horizontally. Any departure from horizontality indicates later tectonic deformation.

3. Principle of cross-cutting relations: a geologic feature (e.g., igneous intrusion) that cuts across another body of rock is younger than the rock it cuts across

4. Principle of included fragments: fragments included in a large body of rock are older than the rock in which they have been included (e.g., xenoliths, clasts in a conglomerate)

5. Principle of faunal succession: fossils occur in a definite and determinable order



Detailed Procedure1. Discussion/Inquiry – 10 minutes

What is time? Pose this question to the group and compile responses on the board. (what do we know about time?) The discussion will probably converge on how time is measured (Earth rotating on its axis = day, vibrations of the Cesium atom = second, etc.). After exhausting the discussion, point out that, quite simply (and consistent with all the ways to measure it) “time is change.” If nothing ever changed, there would be no sense of time (this could lead to a metaphysical discussion of time, but we don’t need to go there).

Because “time is change”, all sorts of changes can be used to measure time, including changes in the Earth (invite the group to list Earth changes that might be used to mark time, e.g., tides, (regular interval), floods (irregular intervals or seasonal), meteorite impacts (highly irregular, long-recurrence, high-magnitude events vs. short-recurrence, low-magnitude events—thank goodness!). Inverse relationship between magnitude and intensity of events.

Segue to geologic time scale—relative scale and putting dates on the time scale.

It is important to remind participants that the geologic time scale was constructed from basic stratigraphic principles, hundreds of years before radiometric dating allowed us to put actual dates on the time line. Earth changes—deposition of sedimentary strata, intrusion of igneous dikes, tilting and folding of strata through mountain building—are all recorded in the geologic record and these events can be sorted out and placed in their relative order. The advent of radiometric dating allows us to put numbers—dates--on these events. The older term “absolute dating” should be avoided, because it implies a finality or certainty that is antithetical to how science works.

Activity 1.4a: If there are participants who are not familiar with the fundamental stratigraphic principles discussed in the background information and alluded to in the paragraph above, this activity provides practice in constructing a relative chronology from basic principles. This can be done as a group or assigned as homework. The key appears below.

Note: This is a tricky diagram, and there will probably be spirited disagreement about the last few events. Participants should be encouraged to justify their choice(s) with the appropriate logic based on application of the stratigraphic principles. There may not be a clear “right answer”.

Key to symbols: “V” is a complex metamorphic rock. Units A, S, and E are intrusive igneous rocks; M is marked with the same symbol but probably represents an extrusive igneous rock, e.g., lava flow (and thus is older than X). X and L are some undistinguishable sedimentary rock, F, B, J are shales, G is a limestone, H, R, and D are sandstones or mixtures of sand and gravel. Z is a conglomerate. P, K, C, And T are faults. N refers to the damage to the house.



2. Construction of Timeline: 30 minutes

Have participants work as a group to construct a geologic timeline from cash register tape at a scale of 1m = 50 my years. A. Let participants figure out how long the time line will be and how to mark off the time

line.B. Have participants mark the Eons, Eras, Periods, Epochs and significant physical and

biological Earth historical events identified on Activity Sheet 1.4 on the geologic time line. Participants should figure out and agree on a consistent way to distinguish between Eons, Eras, Periods, Epochs on the time line.

3. Whole Class Discussion of Timeline: 20 minutesDiscussion Prompts:

How do we know how old a rock is? Why do we have so many events clustered at the recent end? What perspective does this time line offer? What are the major periods in geologic time? How do we identify the end of a period? How does the textbook (non-scaled) depiction of the geologic time scale differ from the

timescale we constructed to scale? What bias does this represent? What misconceptions might this lead to?

Consider how long it took for life to evolve from single-celled stage to multi-celled stage, and how rapidly all other biological changes occurred after this threshold was crossed. What does this imply about the difficulty of this transition, and what might it mean for the likelihood that there is complex (multi-cellular) life on other planets? [the Rare Earth hypothesis of Peter Ward and Daniel Brownlee]

Common Misconceptions



Time – People do not really have misconceptions about what time is, but they have incomplete conceptions of geologic time, chronologic order, and significance of certain geologic events. Children think of time in two categories (more ancient and less ancient). Adults have three categories (extremely ancient, moderately ancient, and less ancient). (Ault, 1982; Trend, 1998, 2000, 2001).

Ault, C. R., Jr. (1982). Time in geological explanations as perceived by elementary-school students. Journal of Geological Education, 30, 304-309.

Trend, R. D. (1998). An investigation into understanding of geological time among 10-and 11-year-old children. International Journal of Science Education, 20(8), 973-988.

Trend, R. D. (2000). Conceptions of geological time among primary teacher trainees, with reference to their engagement with geoscience, history, and science. International Journal of Science Education, 22(5), 539-555.

Trend, R. D. (2001). Deep time framework: A preliminary study of U.K. Primary teachers' conceptions of geological time and perceptions of geoscience. Journal of Research in Science Teaching, 38(2), 191-221.

Embedded Assessments Do participants understand basic chronology? Do participants appreciate the differences between relative chronology and numerical

methods?MI & OH Benchmarks AddressedMichigan: EG.V.1 MS 4. Explain how rocks and fossils are used to understand the age and


based on observable scientific evidence in the geologic record.Systems & EnergyThis activity establishes a framework for investigating how systems act over time and how the geosphere and biosphere have evolved.Elements of Inquiry1. Learners engage in scientifically oriented questions.5E ModelEngage –

Activates prior knowledgeEstablishes a problem: How are geologic time and geologic events organized

chronologically?Elicits learner ideas

Explore – Explore learner ideas

Explain –Explain how geologic time is divided and used to organize a chronology of events.



ACTIVITY #1.5: Mapping fossil distribution data on state county map

Purpose and Goals of the activity: To connect the fossil examination activity with the timeline activity; to see patterns in the geographic/temporal distribution of fossils.

Main “take home” message: Fossils are more than clues to past environments; because of the Principle of Faunal Succession, fossils provide data to help map the distribution of rocks of different ages, and thus contribute to the construction of geologic maps and elucidating the geologic structure of a region.

Estimated time to complete the activity: 45 minutesMaterials list: Activity Sheets 1.5 – 1 per person (in Activity Guide)

o Directions with Fossiliferous Bedrock Outcrop Timeline (either MI or OH)o County Map (either MI or OH)o Geologic Standard Colors (reproduced in color)

Colored pencils – 1 set per person MI and OH state geologic maps - 1 per classAdvance preparation notesSafety notes/considerations: noneOverview: Participants will plot the location of outcrops of fossiliferous materials on a state

counties map and color-code the counties by the age of the fossils. The goal is to notice patterns on the map and compare those patterns to the patterns present on state geologic maps.

Detailed procedure1. Making the Fossiliferous Outcrop Map

A. Working individually, participants should use the appropriate Fossiliferous Bedrock Outcrop Timeline and state county map to locate the counties where fossiliferous bedrock outcrops occur.

B. Use colored pencils to color code the counties where fossiliferous bedrock outcrops occur according to the age of the fossils. Use colors as close to the standard geologic colors (shown on chart in Activity Guide) as possible.

2. Whole Class Discussion Conduct a whole class discussion about the fossiliferous outcrop maps. Compare student maps to the state geologic maps for OH & MI. Questions to ask:A. What patterns do you see?

1. Examples from MI [model these examples for the Ohio exercise]a. Pre-Cambrian and Cambrian fossil outcrops occur only in the western Upper

Peninsula.b. Devonian fossil outcrops occur on the outer edges of the Lower Peninsula.c. Pennsylvanian outcrops occur only in Mid-Michigan.d. Jurassic fossil outcrops only occur in one county (Ionia).

B. How do these patterns compare to the state geologic maps? Why do your maps only show some of the counties colored in? Why do the state geologic maps include all of the counties colored in?



C. Why do you think there are not fossil outcrops found in every county? (Most of Michigan is covered with glacial outwash and moraine deposits from the glaciers.)

D. If there were fossil outcrops in the following counties, what age fossils do you think you would find and why? Emphasize that these answers are hypothesis. 1. Cheyboygan – Probably Devonian2. Macomb – Probably Devonian3. Montcalm – Maybe Jurassic?4. Livingston – Maybe Mississippian? Maybe Pennsylvanian?

E. Ohio Questions – [model the questions above, based on Ohio counties]

Concerns to look forNote that in OH & MI, there are Pleistocene fossils of Mastodons, but these occur in glacial

cover and not in bedrock outcrops. Therefore, they are noted on the geologic timeline, but not on the map.

References: Michigan Rocks www.educ.msu.edu/michiganrocksColors http://geology.about.com/library/bl/time/blcolorus.htmMichigan and Ohio geologic bedrock and surficial geology mapsEmbedded Assessments Are participants locating fossils on maps correctly? Are participants making connection between fossils and past environments?Are participants asking questions that indicate they are understanding the interesting problems

that these fossils pose?MI & OH Benchmarks AddressedMichigan: EG.V.1 MS4. Explain how rocks and fossils are used to understand the age and


based on observable scientific evidence in the geologic record.Systems & EnergyThis activity establishes a framework for investigating how systems act over time and how the geosphere and biosphere have evolved.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage –

Activates prior knowledgeEstablishes a problem: Where do fossils outcrop in our state? What can these fossils tell us

about the geologic history of our state?Elicits learner ideas

Explore –



http://geology.about.com/library/bl/time/blcolorus.htm

http://www.educ.msu.edu/michiganrocks

Explore learner ideasExplore patterns in data

Explain –Explain what these patterns tell us about the geologic history of our state

ACTIVITY #1.6: Sediment & Rock Exploration Part I

Purpose and Goals of the activity: To describe the texture and composition of sediments and sedimentary rocks, and use these observations to interpret the depositional history of the sediment.

Main “take home” message: Simple, easily observed physical properties of sediment grains tell a story of change of at the Earth’ surface and gives clues to the processes responsible for that change.

Estimated time to complete the activity: 45 minutesMaterials list: samples of (1 each)

beach sand, river sand alluvial sandcarbonate sand

hand samples - 1 per 1or 2 teacherswell-sorted sandstone conglomerateshalelimestone

binocular microscopes -4 handlenses – 1 per teachergrain-size comparatorssorting and rounding images (handout)Activity Sheet 1.6 – 1 per teacher (in Activity Guide)Advance preparation notes: 1. Set up stations with binocular microscopes and sand. 1 station for each sand sample2. Prepare kits of rock samples. Each kit should contain 1 of each of the rock samples.3. Read Background NotesSafety notes/considerations - NoneOverviewParticipants will describe the texture and composition of the sediment and samples. In the

following activity on Day 2, participants will explore how water sorts sediment. Finally, participants will be able to come back to the descriptions made on Day 1 to make interpretations of the processes responsible for formation of these rocks.



Background Notes: Sediments and Sedimentary rocks

Sedimentary rocks are those that are derived from the weathering and erosion of pre-existing rocks, or are formed by chemical or biological precipitation. Sedimentary rocks are unique among the three rock types in forming at the surface of the Earth. Thus, unlike metamorphic and igneous rocks, sedimentary rocks are the result of exogenic processes, and these processes leave their imprint in the texture and composition of sediments. Therefore, sedimentary rocks potentially contain a record of Earth-surface conditions from the time of their deposition. Geologists use sedimentary rocks to reconstruct paleoenvironments, create paleofacies and paleogeographic maps, and determine the composition of ancient atmospheres and oceans.

A number of processes are involved in sedimentary rock genesis, including: physical and chemical weathering of the parent rock; transportation of the weathered products by wind, water, or ice; deposition of the sediments and compaction and cementation of the sediment into solid rock (lithification). The sequences of events within this sedimentary cycle may be very complex. Material may be eroded and redeposited numerous times before being buried and lithified. More than one transport mechanism may be involved during a single cycle of erosion-transport-deposition.

Mechanical and chemical sorting of the parent material takes place during weathering, erosion , and transportation. Mechanically, transportation mechanisms (e.g., streams) sort and deposit materials by size and weight while materials are more or less continuously attached chemically. In general, the longer that sedimentary particles are subjected to these sorting processes, the more complete the alteration of the parent materials, although some processes (e.g.,, glacial transport) may mix rather than sort particles of different physical properties.

Texture and composition are most important in classifying sedimentary rocks and interpreting the history of erosion-transport-deposition recorded in the rock. Sedimentary rocks are divided into two major groups on the basis of texture and composition: clastic (or terrigenous) and chemical/organic (including the carbonates—limestone-- and chemical precipitates, e.g., gypsum, and halite).

CLASTIC SEDIMENTARY ROCKS--TEXTUREThese are derived from the weathering, erosion, and transport of preexisting rock. The texture

of a sediment, (that is, the grain size, sorting, and rounding of sedimentary particles in a sedimentary rock) are important indicators of the transport history of the rock:

Grain size tends to decrease as the amount (distance or time) of sediment transport increases. Grain size is described using standard terminology that is based on quantitative measurement of grain size using sieves. Coarse grained = .2 mm diameter; medium grained = 1/16 – 2 mm diameter; fine grained = <1/16 mm diameter. Grain size can be qualitatively assessed in the lab using a grain-size comparator (see comparator).



Sorting refers to the range of sizes of particles in a sediment. A well-sorted sediment consists of one dominant grain size. Again, the degree of sorting increases as transport of the sediment increases. The following terms are used to describe sorting:Well-sorted = all grains about the same sizeModerately sorted (many, but not all, grains the same size)Porly sorted = a mixture of large and small grains

Sorting is determined using visual comparison charts (see figure, below and in Activity Guide).

Rounding is a measure of the degree of angularity of the grains. As with sorting, the degree of rounding tends to increase with increasing transport effects; the better rounded the grain, the more transport the sediment has experienced. Rounding is described in qualitative terms, using visual comparison figures: well-rounded, sub-rounded, angular (see figure below and in Activity Guide).

Well-rounded, well-sorted sediments are termed texturally mature, and indicate deposition in an environment in which sedimentary grains can be extensively reworked.

Poorly-rounded, poorly-sorted sediments are termed texturally immature, and indicate deposition in an environment close to the origin of the sediment source; in other words, these sediments have not been extensively transported and/or reworked.

The clastic sedimentary rocks are differentiated primarily on the basis of grain size. From large-to-small, the most common clastic sedimentary rocks are:ConglomerateSandstone



SiltstoneShale

Note: sand is a size term, and does not refer to a particular composition. Most people assume all sand is quartz sand (especially people from the Midwest), but sand may be all carbonate grains (as in the beaches of south Florida) or even gypsum (White Sand Dunes National Monument).

CLASTIC SEDIMENTARY ROCKS—COMPOSITIONThe composition of clastic sedimentary rocks is a reflection of 1) the composition of the parent or source rock and 2) the amount of time and/or distance the sediment has experienced before burial and lithification.

Sediments deposited close to the source area will closely reflect the composition of the source rock; with increasing exposure/transportation, minerals begin to chemically and physically break down according to their stability at the Earth’s surface.

Mafic minerals (e.g., pyroxenes, amphiboles, olivine) are most susceptible to weathering/erosion effects; quartz is the most stable mineral at the Earth’s surface. Thus, sediments that comprise pure quartz have likely been subjected to considerable transport and exposure, and likely multiple cycles of exhumation, transport, and deposition.

Detailed Procedure

1. Examination of sediment (sand) samples: 25 minutesAsk participants to examine the four sediment samples and make a list of how the samples differ. Participants should rotate through stations with each sediment sample. After individuals have had a chance to make their own observations, convene as a group and compile their observations on the board. This should lead to a discussion of grain size, grain shape, grain roundness, and grain composition (mineralogy). After the participants have discovered these parameters through their own inquiry, distribute the handout (grain size-sorting-rounding images) and have the participants characterize each sample using the handout.

Next, brainstorm possible causes (processes) that might explain the differences between the samples. This should lead to a discussion of parent (source) rock, type of weathering process, erosion processes (wind, air, water), amount or distance of transport. Process leads to product; sediments are transported and deposited (processes) in depositional environments (product). We will explore these processes in Activity 2.1

2. Sedimentary rock exploration: 20 minutesProvide participants with hand samples of the different sedimentary rocks and handlenses. Have them use the sediment description guide to characterize the rocks (grain size-sorting-rounding). After each person has had a chance to closely examine the rocks, convene as a group to discuss the differences between the samples and what these differences might be



indicating about differences in Earth processes during the deposition of each rock, and the possible depositional environment(s) represented by each rock.

Embedded Assessments Are participants making careful observations? Are participants connecting the features they are seeing to possible environments of

formation or processes?

MI & OH Benchmarks AddressedMichigan:

EG.V.1 MS4. Explain how rocks and fossils are used to understand the age and geological history of the earth.

EG.V.1 MS2. Explain how rocks are formed.Ohio:


Systems & EnergyThis activity helps participants consider some of the constituents of the geosphere and how they are classified. Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage –

Activates prior knowledgeEstablishes a problem: How can we describe sedimentary rocks and what do they tell us

about where they were formed?Elicits learner ideas

Explore – Explore learner ideasExplore patterns in data

ACTIVITY #1.7:Review of the day and Homework #1

Purpose and Goals of the activity: To allow participants to reflect on what they learned in Day #1.

Estimated time to complete the activity: VariableMaterials list: Activity Sheet 1.7 (in Activity Guide)Detailed Procedure1. Review of the day. Review the significant learning outcomes of the day. Have teachers share

questions, ideas, reactions, etc.



2. As homework, each person should write a short reflection about the days activities. These reflections will be turned in at the start of Day #2.

Reflections should address.1. What did you learn from today that you didn’t know before?2. What questions do you still have?AssessmentFormative Assessment – Facilitators can use these reflections as formative assessments.5E Model : Explain – Synthesize activities

Evaluate – Participants synthesize and reflect on what they learned during the day.



DAY 2

ACTIVITY #2.1: Wrap-up sediment exploration

Purpose and Goals of the activity: to complete observations and discussion from Day 1’s sediment description exercise. Main “take home” message: Sediment grain size, shape, and sorting reflect the transport history of the sediment, and can be used to reconstruct the environment in which it was deposited.Estimated time to complete the activity: 1 hour

ACTIVITY #2.2: Stream Table Exploration

Purpose and Goals of the activity: To use a stream table and settling tube to explore how streams/river processes change the Earth and how this change is recorded in sediments and sedimentary rocks.Main “take home” message: Sediment grain size reflects its transport history, and can be used to reconstruct the environment in which it was deposited.Estimated time to complete the activity: 1 hourMaterials list: stream tablesettling tubesbuckets for water,handout (diagram of depositional environments)sediment grain-size comparatorssorting images,handlenses,filter paperclear drinking strawsActivity Sheets #2.2a, 2.2b, 2.2c, 2.2d (in Activity Guide)Advance preparation notes: Facilitator must make sure the stream table is set up and that a source of water (and paper towels) is available.Safety notes/considerations: Be prepared to mop up water.Overview: Participants will divide into two groups; one will use the stream table while the other group uses the settling tube. After everyone has cycled through both exercises, the group will reconvene to discuss their findings as a group.

Detailed Procedurea) Description of the procedureDivide the group into two, have one group work with the stream table while the other

group works with the settling jar, then switch activities. Finally, reconvene as a group and discuss observations.



Activity 2.2 - Stream table exploration.Activity 2.2a. Relationship between environmental energy and sediment deposition--The

stream table should be filled with unsorted sediment (a mixture of sand, silt, and clay) and the water allowed to run long enough to begin to separate or sort the sediment by grain size. The larger (coarser) grains should remain in a “proximal” position (near the “mouth” of the river produced by the flow), and finer grains should be carried farther out into the settling basin (“ocean” or “lake”). Participants should create a sketch map showing the distribution of sediment types (sand/clay) (facies) and label the map with arrows showing direction of increasing/decreasing energy and a separate arrow indicating the “onshore/offshore” (or “proximal/distal”) directions.

Allow the water to flow through the stream table for several minutes, at least until visible sorting of coarse and fine material has commenced. Participants will sample sediments from the stream table on a proximal-distal transect, examine each sample and describe the degree of sorting. Sample the sediment by inserting a clean straw into the sediment as a coring device; if there is not enough sediment accumulated in the distal portion of the stream table, the sediment-charged water can be collected with a straw and left to dry on a filter paper.

Participants will then describe the grain size and sorting of each of their sediment samples (fill out the data sheet).

Activity 2.2b. Transgression/regression demonstration—After Part A is completed, take a bucket and carefully pour in enough water to create an “ocean” in the lower (distal) portion of the stream table. Plug the outlet so the water does not escape. Have students draw a sketch map of the stream table showing the position of the shoreline. Talk about what sediment types one would expect to see on the “beach” and what sediment one might expect to see in the offshore environment and have participants overlay sediment type on their map (using standard symbols for sand and clay). Carefully add more water, causing sea-level to “rise”. Have participants sketch the new position of the shoreline. Discuss the direction of migration of the environments and their associated facies.

Activity 2.2c Settling jar explorationHave participants make a sketch of the settling tube and the distribution of different sediment types in the tube, then shake the tube thoroughly and record their observations on what happens. Sketch the result after the disruption. Discuss the relationship between energy and settling time (coarser grains settle out first, clay may remain in suspension for hours) and the implications that has for interpreting depositional environment from sediment type—what kinds of environment would you expect to find sand? Shale?

Activity 2.2d Sediments, environments, and processes (facies)1. Return to sediment samples and re-examine them in light of the stream table/settling tube

exercises. Have participants arrange the samples in order of “most transported to least transported” or “least altered from parent material” to “most altered”. Discuss possible environments of deposition for each sample (complete data sheet). Participants may have done this in activity 1.6. Have them revisit these sequences and possibly create new sequences based on their stream table observations. Draw a simplified version of this diagram on the board or overhead projector to link sandstone texture to depositional history:



[Reproduced with permission from Fichter, L.S., and Poche, D.J., Ancient environments and the interpretation of geologic history. New York, Macmillan Publishing Co.]

2. Have participants map (color) the distribution of different sediments they would expect to find in the various environments shown on the diagram (Activity sheet 2.2d, above) of major depositional environments.

3. Have participants complete the table showing the relationship between grain size, energy, and depositional environment.

b) Talking pointsi. Key concepts and points: relationship between energy and transport and

resulting sediment deposit; sedimentary formation process, connecting facies to the processes responsible for these lateral relationships.



ii. Take home message: different depositional environments are characterized by different energy levels, and this is reflected in the type of sediment deposited in these environments; therefore, sediments can be used to infer ancient depositional environments

iii. Possible questions or prompts to ask:1. How is energy of the transport medium related to the kind of sediment that is entrained and deposited?2. How might glacial (ice) transport differ from fluvial transport? What kinds of sediment, degree of sorting, rounding, etc., might you expect in a sediment that is transported by ice instead of water? 3. How would wind (Aeolian) transport differ from fluvial transport? What kinds of sediment, degree of sorting, rounding, etc., might you expect in a sediment that was transported by wind instead of water?4. What characteristic(s) of fluids (air, water, ice) is/are important in determining the type of sediment the fluid can entrain?

c) notes on potential misconceptions: 1. Most people have not thought about sea-level rise and fall in terms of migrating environments but only in terms of water level changes. Transgression and regression occurs over timescales not observable in human experience, so most people will think of transgression in terms of “flooding”, a temporary condition, and not appreciate the long-term effect of environmental change associated with sea-level fluctuation. This is in contrast to most portrayals of sea-level change in movies, where sea-level rise is instantaneous (and temporary), e.g., due to meteorite impact (“Asteroid”) or catastrophic melting of glacial ice caps (“The Day After Tomorrow”).2. Possible confusion of layers in the settling tube with the stratigraphic column

d. Concerns to look for: Confusion of sea-level rise with “flooding”, allusions to the Noachian flood

Embedded Assessments Are teachers recognizing that larger size particles are not carried as far as smaller

particles? Are teachers noticing areas of erosion and deposition? Are teachers noticing order of particle sizes in graded beds? Are teachers able to apply these new principles to explain and interpret environment of

formation for different rock samples?MI & OH Benchmarks AddressedMichigan:

EG.V.1 MS 2 - Explain how rocks are formed. EG.V.1 MS 3. Explain how rocks are broken down, how soil is formed and how surface

features change.



Ohio: Identify that the lithosphere contains rocks and minerals and that minerals make up rocks.

Describe how rocks and minerals are formed and/or classified Describe the interactions of matter and energy throughout the lithosphere, hydrosphere,

and atmosphere. Describe the processes that contribute to the continuous changing of Earth's surface (e.g.,

earthquakes, volcanic eruptions, erosion, mountain building and lithospheric plate movements).

Systems & EnergyThis activity helps participants consider some of the interactions between the geosphere and the hydrosphere. Participants also explore the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage –

Activates prior knowledgeEstablishes a problem: How does water shape the land and transport/deposit sediment?Elicits learner ideas

Explore – Explore learner ideasExplore patterns in dataExplore how water transports and sorts sediments

Explain –Use evidence from stream tables and settling tubes to explain the environments of

deposition of some sedimentary rocks.Elaborate –

Use what we learned to interpret different rock samples

ACTIVITY # 2.3: Facies Mapping

Purpose and Goals of the activity: To apply observations made during the stream table exercise regarding sediment entrainment and deposition and the relationship of different sediment types to modern depositional environments, to an ancient example.Main “take home” message: Principles of sediment distribution observed in modern depositional environments can be used to reconstruct ancient depositional environments.Estimated time to complete the activity: 1.5 hrMaterials list:Coarse-grained sandstone (several samples)Fine-grained sandstone (several samples)



Shale (several sample)Limestone (several samples)Sheet 2.3, Map #1, Map #2 (in Activity Guide)Advance preparation notes1. Read Background Notes2. Lay out sedimentary rock specimens around the classroom so that an onshore-offshore gradient is defined (sandstone to one side, shale in an intermediate position, limestone in a distal location relative to the clastic rocks). 3. Lable each rock with a number.Safety notes/considerations: noneOverview: Using the classroom as a field area, participants will (1) draw a base map and plot the position of the “outcrops” on the map, (2) describe the texture of each rock type and identify the rock, (3) interpolate between “outcrops” and draw lines separating the different facies (rock types) on the map, and (4) interpret the depositional environments represented by the type and distribution of facies.

Background Notes: Introduction to Facies and Depositional Environments

The genetic relationship between depositional process and rock texture is the primary tool to get to interpretation of the depositional environment.

Problems with using uniformitarianism inference in reconstructing depositional environments: certain ancient depositional environments no longer exist (epeiric seas) the distribution of environments has changedCaution with applying environmental models: no two depositional environments are exactly alike--geographic and temporal separation models should not restrict our thinking (cramming one's data into existing model rather than

considering alternatives). With these caveats in mind, we will outline the main tools used in basin analysis (the interpretation and classification of depositional environments).

Prerequisite: introduction of Facies: The word is Latin for "appearance, aspect""a stratigraphic unit distinguished by lithologic, structural, and organic characteristics"..a rock unit that is recognizable (distinct) on the basis of some chosen criterion:

Facies are used in two different senses:1. Physical, descriptive sense, e.g., Lithofacies-defined on the basis of rock type, physical characteristics, e.g., "sandstone

facies" Biofacies-defined on the fossil content2. Interpretive sense--Every sedimentary environment is characterized by a suite of physical, biological, chemical characteristics that produce a distinctive body of sediment--a sedimentary facies. Thus, different facies can be used as an interpretive tool (diagnostic of different sedimentary environments). Thus, we may speak of a "fluvial facies" or "marine facies", referring to a whole package of individual characteristics.



TOOL 1: Facies Associations--It is difficult to make an environmental interpretation on the basis of a single facies, e.g., cross-bedded sandstone may be terrestrial (eolian) or fluvial in origin; similar facies may form in different environments.

Our interpretive power is strengthened by looking at the lateral and vertical relationships of facies--facies associations. Different depositional environments are characterized by different lateral and vetical facies associations. Thus, a fluvial sand may be adjacent to fine-grained overbank deposits; an eolian sand might abut coarse, immature alluvial fan sediments. The lateral facies relationships help clarify the environmental interpretation.

Vertical associations. Lateral facies are related in a vertical sense as environments migrate through time. This is Walther's law. Lateral migration produces characteristic vertical sequences for different depositional environments. Two basic patterns: fining upward (transgressive), coarsening upward.(regression/prograding)

TOOL 2: Geometry of facies--3-D shape, e.g., sand bodies may be sheets, blankets, prisms, pods, ribbons, shoestrings. Prisms/wedges are characteristic of alluvial fans, deltas; shets, blankets are characteristic of shallow marine, beach, desert; ribbons/shoestrings form in fluvial or tidal channels. Again, the same geometry can develop in more than 1 environment; geometry alone cannot distinguish a depositional environment.

TOOL 3: Lithology—A. Gross lithology. Environmentally sensitive rock types are useful depositional environment indicators, e.g.:

limestone is characteristic of warm, marine environmentsevaporites: arid continental or restricted marinecoal: fluvial or marginal marine swampscoarse terrigenous: fluvial, alluvial

B. Texturesi. carbonates

spar cement--high energymicrite matrix--low energyquartz content decreases away from source (shoreline)

ii. clastics (texture)grain size/sorting (distance from source)shape/sphericity--new analyses show promise (Fourier analysis)rounding--use with caution because of recycling

TOOL 4: Sedimentary structures--any one is not unique to one depositional environment, although ripple indices may distinguish wind vs. water-generated ripples

Also used as paleocurrent indicators: asymmetrical structures (ripples, foresets, flute,s grooves)

TOOL 5: Geochemical considerations--i. Major element composition of authigenic minerals reflects conditions in the

depoisitonal basin, but there's not much variation between, for example, calcium carbonate content in limestone from different parts of the marine environment.

Allochthonous grains (clastic) composition reflects the source, not depositional environment.

ii. Trace elementsa) Boron--more in sea water than freshb) Cr, Cu, Ni, V, Ga also investigated for paleosalinity utility



c) C/S ratios of organic matter: molecular weights of oganic carbon used to distinguish marine/non-marine organisms

iii. Carbon-oxygen isotopesa) used to distinguish marine/non-marine

[freshwater is depleted in 13C and 18O relative to seawater so that 13C, 18O of freshwater carbonates and shells are lower than that of marine][oxygen: fractination of 18O/16O during evaporation of seawater, heavier 18O remains in the ocean]CAUTION: diagenesis may alter ratios, especially oxygen isotope ratiosOxygen isotopes are also temperature dependent, and thus potential paleotemperature indicators (if they haven't been compromised). [18O decreases with increasing temperature]

TOOL 6: Fossils--Organisms have environmental tolerances/requirements (e.g., salinity, temperature, turbidity--environmental energy). If we know the tolerances for each group, we can make assumptions about the environments represented by the rock in which the fossils are found. Some of the most abundant fossils in the Midwest are animals that belong to groups that are known to be exclusively marine: trilobites, brachiopods, bryozoans, cephalopods. Clams and snails are less diagnostic, as some members of these groups are known to inhabit fresh water environments.

Summary: the Major environments:Continental: fluvial, alluvial, desert, lacustrine, glacialMarginal marine: deltaic, beach/barrier island, estuarine/lagoon, tidal flatMarine: shallow shelf/reef, slope, deep sea

See summary table, next page--



ENVIRON-MENT

GEOMETRY LITHOLOGY FACIES ASSOCIATIONS

SEDIMENTARY STRUCTURES

SEDIMENT TEXTURE

FOSSILS

FLUVIAL Linear, sinuous

Sandstone, shale, siltstone

Main channel (sand), overbank (shale)

Assymetrical cross-bedding

Immature-to-mature

Clams, snails

EOLIAN Tabular Sandstone Evaporates (playa lake) alluvial fan

Large-scale cross-bedding

Mature-well rounded, well-sorted

rare

LACUS-TRINE(LAKE)

Silt, mud (shale)

Alluvial, fluvial Fine-scale varves

Well-sorted

Fresh- water fish, clams, snails, plants

GLACIAL Variable Variable Variable Variable Variable None

DELTAIC wedge Sand-silt-mud

Fluvial, lacustrine, beach, overbank

Cross-bedding, bioturbation

Fine-grained muds, well-sorted sands

Trace fossils

BEACH linear

ESTUARINE Dendritic Fine-grained

Coastal, fluvial Bioturbation Fine-grained

Restrict-ed fauna

TIDAL FLAT Variable: linear, tabular, planar

Muds Beach, neritic, fluvial

Tidal lamination, bioturbation

Fine-grained, well-sorted

Restrict-ed

CLASTIC SHELF

Tabular/ planar

Sand-silt-clay

Beach, fluvial,

CARBONATE SHELF

Tabular/ planar

Carbonate Tempestites Marine invertebrates

REEF Mound Carbonate Fore-reef, back reef

Massive Corals, algae, sponges

DEEP OCEAN

Planar/ tabular

Mud Mud Plankton (forams, radiolaria etc.)



Detailed Procedure

1. Construction of initial facies map. Arrange the sediment samples around the room as described under “Advance preparation notes”. Explain that participants will plot the location of each rock on their base map (Activity Sheet), describe each rock (Activity Sheet) and assign each to a facies (e.g., sanstone, limestone, shale, or beach-shelf-reef, etc.) and create a paleofacies map by sketching in inferred lines of contact between the different facies. Participants will then color the map using the designated color scheme (limestone = blue, sandstone = yellow, shale = gray).

Note that with so few data points (rock samples) there should be significant variation between the maps! There is NO reason for two different people to turn in identical maps!

2. Construction of facies map at time 2. After everyone has plotted the location of the rocks in 1, above, and while they are completing their colored maps, re-arrange the samples so that the position of the shoreline (represented by the sandstone samples) is changed, moved laterally to correspond with either sea-level rise (transgression) or in the opposite direction to indicate sea-level fall (regression). Instruct the participants to construct a new map (Activity Sheet) and rock description sheet for this new situation, which represents the same geographic area (the same landmarks are used) at some time, millions of years after the situation they mapped in 1, above.

3. Reconstruction of process: Invite participants to compare the two maps and answer the following questions:

a) During Time 1, in which direction is the shoreline (land)? In which direction is the open ocean?

b) During Time 2, in which direction is the shoreline (land)?c) What has happened between Time 1 and Time 2? How do you know?

b) Talking points (see questions embedded in procedure, above)i. Key concepts and points: Reprise of the morning’s key points--Different

depositional environments are characterized by different sediments. These differences are due in large part to the energy of the depositional mechanism (water, in this case); high-energy, nearshore environments are characterized by coarser-grained sediments (sand); quiet, low-energy offshore environments are characterized by settling out of fine-grained). These relationships, observed in modern environments (this morning’s stream table and settling tube experiences) are preserved in the sedimentary rock record, and form the foundation for reconstructing ancient environments.

ii. Take home message: The present is the key to the past, in reconstructing ancient sedimentary environments.

iii. Possible questions/prompts (see questions embedded in procedure, above). The classic onshore-offshore lateral sequence of sandstone-shale-limestone is idealized and not an absolute model. Invite participants to envision a landscape in which fine-grained sediments might be deposited close to shore, or sand transported far from shore (in other words, construct exceptions to this idealized model). Do such exceptions negate the value of the classic model? Explain.



Embedded Assessments Are participants able to identify the rock samples? Are participants able to identify environments from rock samples? Are participants able to make a simple geologic map? Are participants able to explain the changes they see in the two maps?MI & OH Benchmarks AddressedMichigan:

EG.V.1 MS 1. Describe and identify surface features using maps. EG.V.1 MS 2 - Explain how rocks are formed. EG.V.1 MS 3. Explain how rocks are broken down, how soil is formed and how surface

features change. Ohio:


Describe the interactions of matter and energy throughout the lithosphere, hydrosphere, and atmosphere


Systems & EnergyThis activity helps participants understand the organization of the geosphere and hydrosphere. Participants also apply the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage –

Activates prior knowledgeEstablishes a problem: How can we begin to use rock samples to understand changes and

processes responsible for those changes?Elicits learner ideas

Explore – Explore learner ideasExplore patterns in dataExplore how geologists use maps to collect and organize data

Explain – use evidence to identify rock types and environments of formationElaborate – Apply understanding of rock types as indicators of past environments.



ACTIVITY #2.4: From lateral to vertical relationships: Stratigraphic columns

Purpose and Goals of the activity: To understand the history of Earth change as recorded in the vertical sequence of sedimentary rock types (stratigraphic columns); to relate this vertical sequence to the original lateral relationship of facies (Walther’s law).Main “take home” message: The vertical succession of sedimentary rock types tells a story of sea-level rise and fall, laterally shifting environments through time.Estimated time to complete the activity: 1 hourMaterials list:Facies maps from the previous activity (2.3)Handout of stratigraphic columns to interpret (Activity Guide #2.4a,b,c,d)Stratigraphic columns of Michigan and Ohio (Activity Guide)Advance preparation notes:1. Read background notes

Background Notes:Review powerpoint on T/R sequences and Walther’s law (“Sea level.ppt”)

Detailed Procedure

2.4a: Constructing a basic stratigraphic column from facies maps. Begin with participants taking their two facies maps and stacking them (Time 1 on the bottom, Time 2 on top, in the same orientation—North arrows aligned) and then sketching (on graph paper) the vertical sequence of facies at three locations on their map (one point located in the shallowest area, one in the deepest, and one in an intermediate location). Assume, for the sake of simplicity and uniformity, that each facies is 10 meters thick, and use a reasonable scale on the graph paper (if squares are 1 cm, then 1 cm to 1 m would be appropriate). Participants should end up with 3 stratigraphic columns, each with one or two facies (= layers or strata) that may look something like:



Through this simple exercise we have constructed, in a very elementary way, a stratigraphic column, the vertical sedimentary rock record that is preserved at the Earth’s surface, and in constructing the column from the two facies maps constructed earlier, we have demonstrated that the stratigraphic column—the vertical record—is constructed through the lateral migration of facies (environments) through time. This very simple principle is called Walther’s Law, in honor of the German sedimentologist who first enunciated the relationship between laterally adjacent facies and their eventual vertical relationships.

Go through the Sea-level ppt

Activity 2.4b & 2.4c. Vertical Record of Sea Level Change (Idealized Stratigraphic Columns)Refer to Activity Guide 2.4b & 2.4c; complete the exercises, working in groups or with a peer-led discussion. (indicate T/R cycles)

2.4d. From lateral relationships to vertical record: shifting environments through time = stratigraphic columnRefer to Activity Guide 2.4d. Have participants work in groups to construct stratigraphic columns for their location on the maps.

2.5. Return to TimelineReturn to the time line and mark off periods of transgression and regression, based on the observations in 2.4d, above.

Talking pointsi. Key concepts and points: Laterally adjacent facies become

vertically adjacent beds in a stratigraphic column as a result of migration of depositional environments through geologic time in response to changes in sea level. Thus, it is possible to infer sea-level fluctuation from the vertical succession of facies in a stratigraphic column.

ii. Take home message: The record of sea-level change can be read directly from the sedimentary rock record from the vertical sequence of facies; fining-upward indicates sea-level rise (transgression); coarsening-upward reflect sea-level fall (regression).

iii. Possible questions or prompts to ask (see questions embedded in procedure notes, above)

c) notes on potential misconceptions: As for exercise 2.3, confusing transgression/regression with flooding; many people have not thought about sea-level rise and fall in terms of migrating environments



but only in terms of water level changes. Transgression and regression occurs over timescales not observable in human experience, so most people will think of transgression in terms of “flooding”, a temporary condition, and not appreciate the long-term effect of environmental change associated with sea-level fluctuation. This is in contrast to most portrayals of sea-level change in movies, where sea-level rise is instantaneous (and temporary), e.g., due to meteorite impact (“Asteroid”) or catastrophic melting of glacial ice caps (“The Day After Tomorrow”).

d. Concerns to look for:References to Noachian flood as an explanation for the formation of stratigraphic columns

e. Power Point notes: Sea Level pptHandouts for Participants: Included in Activity Guide

Embedded Assessments Are participants able to connect the changes seen in the horizontal maps to

the records shown in a vertical column? Are participants able to identify transgressions and regressions?MI & OH Benchmarks AddressedOhio:

Describe the interactions of matter and energy throughout the lithosphere, hydrosphere, and atmosphere


Systems & EnergyThis activity helps to understand the organization of the geosphere and hydrosphere. Participants apply the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelElaborate –

Apply understanding of rock types as indicators of past environments.



Apply an understanding of changes over time and area to interpretation of stratigraphic columns

ACTIVITY #2.5: Discussion/wrap up

Purpose and Goals of the activity: To allow participants to reflect on today’s activities, and ask questions.

Estimated time to complete the activity: 15 minutes Detailed ProcedureReview the day. Review the significant learning outcomes of the day. Have participants share questions, ideas, reactions, etc. Make a list of unanswered questions to address tomorrow.Assign Homework (see Activity 2.6, below)

ACTIVITY #2.6: Review of the day and Homework #2


Estimated time to complete the activity: VariableMaterials list: Sheets 2.5a & b (Activity guide) Detailed Procedure1. Review of the day. Review the significant learning outcomes of the day. Have teachers share

questions, ideas, reactions, etc.2. Homework includes 2 parts

A. Activity Guide 2.5 – Each participant will complete the facies map and stratigraphic column exercise.

B. Each person should write a short reflection about the days activities. These reflections will be turned in at the start of Day #3.Reflections should address.1. What did you learn from today that you didn’t know before?2. What questions do you still have?

AssessmentHomework assignments

Facilitators will use the homework assignments as formative assessments5E ModelExplain – Synthesize activitiesElaborate – Participants apply what they learned to new situationsEvaluate – Participants synthesize and reflect on what they learned during the day.



DAY 3

ACTIVITY 3.1: Field Experience

Purpose and Goals of the activity: To go beyond classroom and textbook to make direct geologic observations, collect stratigraphic and sedimentologic data and interpret the Earth changes represented by these data.Main “take home” message: The story of Earth change can be “read” from outcrops in our backyard.Estimated time to complete the activity: 3.5 hoursMaterials list:

Handlens Notebook Waterbottle Sunscreen Hat bug spray camera metersticks (2 for the group) grain-size comparators Activity Guide 3.1 sorting/rounding images

Advance preparation notes1. Have all participants read over the “to bring” list in preparation for the trip2. Confirm travel arrangements and provisions for lunchSafety notes/considerations: Avoid climbing on wet, slippery rocks; be alert for poison ivy, take precautions against heat exhaustion with plenty of water and sun protection.

Overview: The major objective of this exercise is to provide participants with practical field experience in collecting geologic data and applying the principles we’ve discussed during the previous 2 days, and serve as an introduction to the local geology. Our emphasis is on producing a legible, complete, and accurate record of observations (FIELD NOTES), including rock type, thickness, grain size, sorting, rounding, bed thickness, lateral continuity of beds, presence of fossils, trace fossils, sedimentary structures, etc.

Detailed procedurea) Description of the procedure

Carpool to site. At the site, review the kinds of observations that participants are expected to make (refer to Activity Guide); give instructions on any local regulations, collecting restrictions, etc., and announce meeting and departure time before the group disperses. Refer to the geologic maps in the Activity Guide, locate the site and determine the age of the bedrock. Facilitators should circulate through the group during the excursion to answer questions and ask questions (see talking points, below).

b) Talking points



i. Key concepts and pointsii. Take home message: We need look no farther than the nearest outcrop of

bedrock for evidence of dramatic changes in the Earthiii. Possible questions or prompts to askWhat is the predominant rock type? What are its characteristics (sorting, rounding, grain size)What might the depositional environment for this have been?c) Notes on potential misconceptions: After spending the previous two days studying

modern sediments and their transformation to sedimentary rock, there may be confusion about the relationship of modern rivers to the sedimentary rocks that the rivers cut into. Naïve intro geology students sometime erroneously conclude that the modern river was responsible for the deposition of the sedimentary rock. Of course, the bedrock is millions of years older than the modern river and not at all related to the origin of the sedimentary rocks exposed as a result of Pleistocene-age erosion.

d. Concerns to look for: Mention of “flood geology” and erroneous timescales in reference to the bedrock and modern topography.

e. Power Point notes: noneFollow-up or homework: see Activity 3.4, belowHandouts for Participants : Activity Guide 3.1Suggested readingsReferences

Embedded Assessments Are participants able to make careful observations of the rocks and fossils? Are participants able to make organized notes of their observations? Are participants able to use what they know about identifying rocks and interpreting

environments to explain what environments the rocks outcrops formed in?MI & OH Benchmarks AddressedMichigan


EG.V.1 MS2. Explain how rocks are formed. EG.V.1 MS3. Explain how rocks are broken down, how soil is formed and how surface


Explain the 4.5-billion-year history of Earth and the 4 billion-year-history of life on Earth based on observable scientific evidence in the geologic record. Describe the interactions of matter and energy throughout the lithosphere, hydrosphere, and atmosphere



Systems & EnergyThis activity helps teachers understand the organization of the geosphere and hydrosphere. Teachers also apply the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.



Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelExplore

Collect field data & look for patterns in dataExplain

Use field data to explain the processes responsible for the depositing the rocks seen in the field

Elaborate – Apply understanding of rock types as indicators of past environments.Apply an understanding of changes over time and area to interpretation of stratigraphic

outcrops and columns

ACTIVITY 3.2: Correlation

Purpose and Goals of the activity: To synthesize data from several stratigraphic columns to learn how geologists develop a chronology of changes over a region.Main “take home” message: Data from several stratigraphic columns can be correlated to show large-scale changes over wide areas and long periods of time. While no single stratigraphic column may show a complete record of all changes, several columns can be linked together to show a more complete picture.Estimated time to complete the activity: 1.5 hoursMaterials listStratigraphic columnsColored pencilsActivity Guide #3.2a and #3.2bScotch tapeAdvance preparation notes1. Read Background Notes

Safety notes/considerationsOverviewParticipants will learn how to correlate two stratigraphic columns and then correlate several columns over a larger area in constructing a regional cross-section.

Background Notes: CorrelationDefinition: "A procedure for demonstrating correspondence (or equivalence) between

geographically separated parts of a geologic unit." The nature of the "correspondence" that is demonstrated is a source of contention and

misunderstanding, even today. One view restricts the meaning of correlation to demonstration of time



equivalency, that is, to demonstration that two bodies of rock were deposited during the same period of time. From this point of view, correlation strata solely on lithologic similarity does not constitute correlation (because of time-transgressive nature of sedimentary deposits).

A broader interpretation of correlation allows equivalency of lithologic, paleontologic, or chronologic criteria, in other words, two bodies of rock can be correlated as belonging to the same lithostratigraphic or biostratigraphic unit even though these units may differ in age. Most geologists today accept the broader view (practical standpoint of physically making correlations) but strive for time significance in the correlations.

The North American Stratigraphic Code, which sets out rules for standardizing stratigraphic nomenclature, recognizes several types of correlation: lithocorrelation (based on lithologic characters and stratigraphic position), biocorrelation (based on faunal content and stratigraphic position, and chronocorrelation (based on age and chronostratigraphic position).

Lithostratigraphic correlation--Caution: correlations based solely on lithostratigraphic grounds may be misleading: physically similar units may be deposited at greatly different times and thus have no physical connection with each other (and cannot properly be correlated with each other). Example: a Cambrian quartz sandstone may look just like a certain Cretaceous sandstone, but they obviously are not correlatable. Lithostratigraphic correlation can be accomplished in two different ways: direct and indirect.

i) Direct correlation is that which can be established physically and unequivocally. Physically tracing a unit in outcrop is the only unequivocal methods of direct correlation.

ii) Indirect correlation. Most correlation is of the indirect type, where we do not have continuous exposure of the rock, and must interpolate between data points (via outcrops, drill holes, geophysical subsurface data, whatever we have). The basic tools of indirect lithologic correlation are lithologic similarity and stratigraphic position. The success of such correlation depends upon the distinctiveness of the characters used in the correlation, and the presence or absence of lithologic change between the areas under study. The greater the number of lithologic characters used in the correlation, the more reliable the correlation.

Example: Colorado Plateau (see figure). Notice that some units pinch out laterally. Other units undergo a facies change, i.e., become sandier or shalyier from one locality to another, but are still considered part of the same formation.

Biostratigraphic Correlation--Biostratigraphic units are observable, objective stratigraphic units identified on the fasis of their fossil content. They can be traced and matched from one locality to another jsut as lithostratigraphic units are traced, and they may or may not have time significance. First appearances of taxa (interval zones) most closely coincide with time lines.

Biostratigraphic units are correlated basically in the same way as litho..matching by identity (fossil content) and stratigraphic position.

Magnetostratigraphic Correlation--Because the polarity time scale can be calibrated radiometrically and paleontologically, polarity events provide a precise tool for chronostratigraphic correlation. Correlation is basically matching pattern of reversals (position and length of stripes). With longer cores and older sediment, correlation becomes more difficult because the magnetostratigraphic record consists of many sets of reversals that may look very much alike. Correlation of these patterns may require independent radiometric or paleontologic age evidence to first establish stratigraphic position. Paleomagnetic events are particularly useful for correlation over long distances (global).



Detailed Procedurea) Description of the procedure

Activity 3.2a – Illustrate on an overhead or on the board how correlations between two stratigraphic columns are made. Have participants work in small groups to complete the correlations in the Activity Guide. Follow up with a whole class discussion of possible solutions/correlations. Be sure to have participants explain their reasoning for the correlations they made, citing evidence as necessary.

Activity 3.2b –Have participants work in small groups to complete the regional correlation. Directions are in the Activity Guide. Participants will need to remove the pages with the stratigraphic columns from their Activity Guide book and tape them together. Each person will make correlations and then color in the major lithologic units. Follow up with a whole class discussion of possible solutions/correlations. Be sure to have participants explain their reasoning for the correlations they made, citing evidence as necessary.

b. Talking pointsi. Key concepts and points: Correlation demonstrates equivalence between two

or more rock units separated. This equivalence may reflect a common environment of deposition, common rock type, common fossil content, or be based on some other shared physical, biological, or chemical property.

ii. Take home message: Even though there is no one place on Earth where the entire stratigraphic record is preserved, correlation makes it possible to piece this record together.

iii. Possible questions or prompts to ask: What is the first step in drawing a line of correlation? What assumptions do you make? How do you (or might you) minimize the assumptions (i.e., make the correlation stronger)?

c. Notes on potential misconceptions: There may be confusion in making the transition from map view to cross-section view.

d. Concerns to look for: References to a high degree of uncertainty or unreliability in making correlations, statements to the effect “one limestone looks like any other”. Correlation is a powerful tool that poses testable hypotheses (e.g., where to drill for oil) and has proven its validity and utility.

e. Power Point notes: noneFollow-up or homework: Activity Guide 3.4Handouts for Participants: Activity Guide 3.2a, 3.2bSuggested readingsReferences

Embedded Assessments Are participants able to make make correlations? Are participants able to identify and explain the changes in environments illustrated by

the correlations? Are participants able to explain the processes responsible for those changes?MI & OH Benchmarks AddressedMichigan









Systems & EnergyThis activity helps teachers understand the organization of the geosphere and hydrosphere. Teachers also apply the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage – How can we see changes over larger areas and longer time spans? Explore

Correlate stratigraphic columnsExplain

Use stratigraphic columns to identify and build a chronology of changes

ACTIVITY #3.3: Time Line Integration

Purpose and Goals of the activity – To put all of the pieces together into a coherent chronology of changes across the region for the past 500 million years.Main “take home” message: The rocks provide clues which can be used to explain the geologic history of the region.Estimated time to complete the activity: 1/2 hour to 45 minutesMaterials list Time line – Activity 1.4Stratigraphic columns and correlations –Activity 2.4, Activity 3.2Advance preparation notes: Prepare a list of the major Earth historical events that have come up in discussion over the last several days that should be included on the timeline.Safety notes/considerations: noneOverview: We will apply the principles, procedures, and tools learned in the facies, stratigraphic column, and correlation activities to help fill in the timeline. Refer to the



stratigraphic columns for the respective state (Ohio or Michigan) and use the knowledge of what facies are typical of different depositional environments to indicate the interval during which the area was covered with a shallow sea, when coal (or reef or other special environments) were present, and when the sea retreated for the last time.

Background Information: refer to previous notes on facies, stratigraphic columns, and correlation.

Detailed Procedure

a) Description of the procedure Return to the time line on the wall. Have the group use the stratigraphic column to identify the major events that are recorded in the stratigraphy of the area. Identify the time periods during which these events took place. Mark the events on paper and tape them on the wall under the time line in the correct chronologic order and position.

Have participants complete Activity Sheet 3.3. You may either have each person complete this writing on their own and share or discuss the questions as a group and allow individuals to take notes to write their own answers later.

b. Talking pointsi. Key concepts and points: Participants should now be able to relate

sedimentary rock type to an appropriate depositional environment, and they should be able to recognize “coarsening-up” and “fining-up” sedimentary sequence and relate them to sea-level change.

ii. Take home message: Much of Earth history can be deciphered by understanding a few relatively straightforward principles of sediment deposition.

iii. Possible questions or prompts to ask: Examine the stratigraphic column(s) for your state. Identify major rock types. What are the possible depositional environment(s) represented by these rocks? Look for “fining-upward” or “coarsening-upward” transitions. What does this tell us about sea-level fluctuations?

c. Notes on potential misconceptions: There are very few states in which a single “composite” stratigraphic column is sufficient to tell the whole story, and the diagrams that we refer to here are idealized/generalized. Lateral facies changes and erosion account for the differences.

d. Concerns to look fore. Power Point notes: none

Follow-up or homework: See Activity 3.4, below.Handouts for Participants: Activity GuideSuggested readingsReferences

Embedded Assessments Are participants able to interpret the sequence of geologic events from a stratigraphic

column and place these events on the time line and elaborate on the chronology of events?MI & OH Benchmarks AddressedMichigan









Systems & EnergyThis activity helps in understanding the organization of the geosphere and hydrosphere. Participants apply the relationship between energy of water in particular depositional environments and the grain size of sediment transported and deposited.Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelElaborate – Synthesize & data and events to produce a chronology of changes over the past 500 million years for the local area.

ACTIVITY #3.4: Review of the day and Homework #3


Estimated time to complete the activity: VariableMaterials list: Activity Sheet 3.4 Detailed Procedure1. Review of the day. Review the significant learning outcomes of the day. Have participants

share questions, ideas, reactions, etc.2. As homework, each person should write a short reflection about the days activities. These

reflections will be turned in at the start of Day #4.Reflections should address.1. What did you learn from today that you didn’t know before?2. What questions do you still have?AssessmentFormative Assessment – Facilitators can use these reflections as formative assessments.



5E ModelExplain – Synthesize activitiesEvaluate – Participants synthesize and reflect on what they learned during the day.



DAY 4

ACTIVITY #4.1: Context

Purpose and Goals of the activity: To set the context for the morning’s activities. We have spent three days examining evidence of Earth change through millions of years; this morning we will consider the major internal and external driving forces for this change.Main “take home” message: The record of Earth change that is preserved in the sedimentary rock column is the result of Earth’s endogenic and exogenic systems.. The sedimentary record is unique in that it is a record of the interaction between the interplay of these two systems.Estimated time to complete the activity: 30 minutes

ACTIVITY #4.2: Tectonics and Sedimentation

Purpose and Goals of the activity: To appreciate the connection between Earth’s internal and external systems, how the geosphere and hydrosphere interact and how this interaction is preserved in the sedimentary record.Main “take home” message: The Earth’s internal tectonic system, powered by radioactive decay, is linked to Earth’s external hydrological system, powered by the sun and assisted by gravity, through tectonic plate collision and the resulting uplift, weathering, and erosion of Earth materials. This interaction is preserved in sedimentary rocks. The position of ancient mountains is documented through correlation of stratigraphic sections.Estimated time to complete the activity: 1 hourMaterials list:

PALEOMAP plate tectonics software Activity Guide 4.2

Advance preparation notes: 1. Confirm computer room reservation2. Play with the software in advance of the session Overview: Participants will use PALEOMAP software to explore plate tectonic movements through Earth’s history. Emphasis is on noting where/when mountains formed in eastern North America, and relating that tectonic activity to the sedimentary record preserved at the Earth’s surface.Detailed procedure

a) Description of the procedureThis activity takes place in a computer lab; each participant should have access to a computer and PALEOMAP software. Participants should be encouraged to explore all the files, but especially the “Paleogeography” file in which they can view plate movement-forward and backward-through Earth’s history. Instructions on accessing the file are included in Activity Guide 4.2 to guide participants through the activity. Have participants answer the questions in



the activity guide. Wrap-up the activity with a discussion of their findings. Emphasize that the continental collision through the Paleozoic Era that formed the ancient Appalachian mountains was responsible for the uplift that caused the sea level changes recorded in the stratigraphic columns.

Make sure to add the orogenic events to the time line.

b) Talking pointsi. Key concepts and points: The plate tectonic story of the Paleozoic Era is one

of continental convergence, culminating in the formation of the “supercontinent” Pangea by the end of the Paleozoic. A result of this plate interaction was the formation of the ancient mountain range in the eastern US that we now call the Appalachians. Sediments she from the various incarnations of this mountain range were deposited in the shallow seas that covered the Midwest, and these mountains are the primary source for the clastic (sandstone, shale) sediments preserved in our area.

ii. Take home message: Earth’s internal energy drives the plate movement that shapes Earth’s exterior and contributes to changes in sea-level. These changes are recorded in the product of erosion of these mountains—sediment--in the stratigraphic record.

iii. Possible questions or prompts to ask: What do the different colors on the PaleoMap animations signifiy? What might we predict for the future of eastern North America? How are these projections made?

c. Notes on potential misconceptions: Many people have heard of Pangea, but few realize that Pangea was only one of several supercontinents that formed during the 4.6 billion years of Earth history. In fact, the phenomenon of supercontinent formation and break-up is referred to as the “supercontinent cycle”. Pangea was only the most recent incarnation of the supercontinent cycle, and there are likely to be more supercontinents in the future (see PALEOMAP “Future” file for animations of future plate movement).

There is also the potential for misunderstanding the paleomaps in the CD animations. Modern-day features, such as the Great Lakes and Hudson’s Bay, are included on these maps to help the viewer get oriented, but many people internalize the map outline as the actual shape of the continent at that time in the distant past.

d. Concerns to look for: Confusion of modern-day map outlines with paleogeographye. Power Point notes: none

Follow-up or homework: noneHandouts for Participants: Activity Guide # 4.2Suggested readingsReferences

Embedded Assessments Are participants able to explain how tectonics are responsible for uplift and sea level

changes?MI & OH Benchmarks AddressedMichigan


Ohio:





Systems & EnergyThis activity helps teachers understand the organization of the geosphere and hydrosphere. Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations5E ModelEngage – Why did the sea level changes noted in the stratigraphic columns occur?Explore – Participants will look for tectonic evidence and patterns in the computer animation related to sea level changes.Explain – Participants will be able to explain the tectonic causes of uplift and sea-level changes.

ACTIVITY #4.3: Glacial Processes

Purpose and Goals of the activity: To understand the Great Lakes landscape (topography) in terms of the glacial and post-glacial processes that have shaped it.Main “take home” message: The modern landscape of the Great Lakes region (the most recent chapter in the story of Earth changes) is the product of glacial advance and retreat during the most recent (Pleistocene Epoch) ice age. Post-glacial modification of the landscape is primarily the result of fluvial (river) processes.Estimated time to complete the activity: 1.5 hrMaterials list:

surficial geology maps (Ohio, Michigan) NOAA narrated powerpoint presentation on “Ice Ages” (26 minutes) Activity Guide 4.3

Advance preparation notes1. Read Background notes

Background Notes: Pleistocene & climate change

Quaternary Period [38 seconds our 24-hour clock!]Pleistocene Epoch (1.6 mybp-10,000 yrs)How the Pleistocene is defined: Lyell's definition: strata having 90-100% extant molluscs Glaciation (but ice caps began forming in the Miocene, so this is not precise)Holocene [Recent] (10,000 yrs to present)



Dramatic climatic shiftsEvidence of climate change: Proving glaciation

Even though glaciers exist today in alpine regions, the concept that great continental ice sheets existed had to be proved. The unconsolidated, poorly sorted surficial materials we call till was originally termed "drift" and was attributed to Noah's flood. James Hutton proposed tht alpine glaciers were more extensive than they are today (in Switzerland, but he failed to recognize evidence of ancient glaciation in his native Scotland!) It raises the questions: if there were no modern glaciers, would we ever have correctly interpreted ancient geological evidence as glacial deposits?

The name most closely associated with "proving" past glaciation is the great naturalist Louis Agassiz (1936) [Swiss, ended up at Harvard; SJG is in his old office]. He was first a very vocal opponent of the idea, but in his effort to disprove it became the most ardent supporter of the idea of past glacial episodes.

"Glacial fingerprints" poorly sorted sediments (or metaseds) wide range of grain sizes, from clay to boulder striated clasts, chattermarks angular to subangular (not well-rounded) immature mineralogic composition dropstones/erratics striated pavement erosional landforms (U-shaped valleys, various alpine features) depositional landforms (moraines, continental glacier landforms)

Glacial Effects Isostatic rebound

Hudson Bay area was eepressed below sea level with the mile-thick ice sheet sitting over it. This area is now rebounding 2 cm/year. [It must rise 80 more meter before it reaches its pre-glacial level.]

change in drainage: damming tributaries (by ice or sediments); create lakes along the glacial margin; set new river coursesGreat lakes: less-resistant bedrock scoured by ice

sea-level biotic effects: force shift in faunal patterns: migrate or go extinct

Geologic record of glaciations1) Late Archean/Early Proterozoic (2.7-2.3 bybp) Gowganda Fm., Canada2) Ediacarian (700 mybp)3) Ordovician (North Africa)4) Siluro-Devonian (S. America)5) Late Paleozoic (230-350 mybp, Gondwana)6) Cenozoic (0-20 mybp; Pleistocene)

Causes of GlaciationGlacial episodes occur when ice sheets accumulation on continents--more snow must fall

in a year than melts. As text points out, it's not a rapid, global deep-freeze; areas near the glacial center experience short summers and longer winters; the climate elsewhere can be highly



variable. Also, glacial intervals are not a solid deep-freeze, but glacial advances alternate with glacial retreat, or interglacial episodes.

North America experienced 4 major glacial episodes and accompanying interglacials in the Pleistocene . From oldest to youngest:

Wisconsinan/SangamonIllinoian/YarmouthKansan/AftonianNebraskan..and there were probably more...

in Europe there were at least 6-7 advances; deep-sea cores show at least 20 warm/cold cycles.Any theory about the cause of glaciation must account for

a) the relative rarity of this event through geologic timeb) the glacial/interglacial alternation typical of a glacial episodes (not a monotonic long-term cooling trend)

HypothesesI. Astronomical [Milankovitch theory]

Glacial periods are the result of extraterrestrial influences that alter the amount of solar radiation received by Earth, specifically, variations in Earth's orbital path: eccentricity (shape of the orbit)

100,000 year cycle between times of maximum eccentricity tilt of axis

shifts 1.5 degree over 41,000 year cycle precession (distance from Sun)

aphelion and perihelion, 11,000 year cycleThese variations would alter the length of the seasons.Problem: glacial periods are not as cyclic as earth's orbital variations are..II. Atmospheric Changea) carbon dioxide greenhouse effect

decrease CO2 = drop temp = glaciationincrease CO2 = traps solar radiation = warm interval

feedback mechanism: cooling = ice=higher albedo (reflected radation) = more coolingHow it works: Extensive plant growth uses up CO2 = temp drop (glaciation)= slows plant growth= CO2 rebound (warming), more plant growth, cycle repeats itselfb) dust cloud, "nuclear winter" hypothesis

volcanism throws dust up, blocks radiation = coolingProblem: many volcanic episodes in the past are NOT correlated with glacial episodes

III. Oceanic controlscirculation of ocean waters, distribution of cold/warm currentsbut this is a product of...

IV. Plate tectonicsContinental configuration. Continents over the poles (high latitudes)=glaciation

Ultimate control is a combination of astronomical parameters and the position of the plates.



Pleistocene and climate changeQuaternary Period/Pleistocene Epoch

Defining the Pleistocene: Lyell: 90-100% extant molluscs Presence of glaciation (Miocene) 1.6 mybp-10,000 ybp

Geologic record of glaciations

Late Archean/Early Proterozoic (2.7-2.3 bybp) Gowganda Fm., Canada

Ediacarian (700 mybp)

Ordovician (North Africa)

Siluro-Devonian (S. America)

Late Paleozoic (230-350 mybp, Gondwana)

Cenozoic (0-20 mybp; Pleistocene)



Evidence of glaciation phenomenon had to be proven! poorly sorted sediments (clay to

boulder) angular to sub-angular clasts immature mineralogic composition striated bedrock, chattermarks dropstones/erratics characteristic erosional landforms

U-shaped valleys, cirques, horns aretes characteristic depositional landforms

moraines, drumlins, eskers, outwash

Glacial Effects isostatic rebound change in drainage pluvial lakes (Fig. 17.14) sea-level fluctuation biotic effects: shift in faunal

patternsCauses of Glaciation

Explanations must account for:Copyright 2006 MSU PROM/SE Supported by the National Science Foundation Agreement No. EHR-0314866 www.promse.msu.edu 69


relative rarity of this phenomenon alternating glacial/interglacial periods

I. Astronomical hypotheses(Milankovitch) eccentricity (shape of Earth's orbit) tilt of Earth's axis precession of Earth's orbit

II. Atmospheric hypotheses carbon dioxide green house effect dust cloud "nuclear winter"

III. Oceanic circulation hypotheses

IV. Plate tectonics

Ultimate control?: combination of astronomical parameters and position of plates



Pleistocene history of the Great Lakes

Youngest:

Wisconsinan Glaciation

Sangamon Interglacial

Illinoian Glaciation

Yarmouth Interglacial

Kansan Glaciation

Aftonian Interglacial

Nebraskan Glaciation

Oldest



Overview: Participants will become familiar with interpreting the surficial map (glacial deposits) of their state and using this map to infer Earth history during the Pleistocene.

Detailed Procedure

a) Description of the procedurePost the large version of the surficial geology map (of Ohio or Michigan) and instruct

participants to refer to their copy in the Activity Guide. Go over the large map as a group, pointing out the key, and ask how it differs from the key on the bedrock geology map (on the bedrock map, different units are mapped by their age; on the surficial map, all the units are from the same geologic epoch—Pleistocene—and are mapped by the type of deposit, e.g., moraine, glacial late, outwash, etc.).

Have participants locate their home county and use the map key to determine what glacial deposits are present. Ask them to think about the surficial deposits in terms of their economic significance, e.g., gravel pits in their county, especially fertile soil, or the opposite, swampy, poorly-drained topography, and list the results of this discussion on the board.

Point out major surficial features, especially moraines, which indicate the direction of ice movement. What is the significance of multiple, concentric moraines? (major periods of stabilization of the ice sheet, and ice retreat in a consistent direction).

Place the glacial events on the time line.End with an overall summary of the major geologic events, the changes they caused, and

the evidence we have for those changes.If there are questions about causes of glaciation, show the powerpoint (26 minutes long),

otherwise, proceed to the wrap-up:The geologic history of a state can be told from the geologic bedrock map and the

surficial geology map. Work as a group to use these maps and construct an outline of the history of your state from the Cambrian to the Recent, using the principles and tools learned during the last 3 1/2 days.

b) Talking pointsi. Key concepts and points: Glaciers shaped the present landscape in the Midwest.

Glacial features in our region include (i) depositional features, such as moraines, which mark the terminus of glaciers, outwash plains, areas of sand and gravel that marked the flow of sediment from the glacier via meltwater; glacial lake sediments, characterized by extremely flat topography and fine-grained sediment (mud); glacial erratics, hummocky, poorly drained topography, and (ii) erosional features, such as glacial scour (Kelly’s Island, OH, grooves)

ii. Take home message: The landscape we see around us in the Great Lakes/upper Midwest was shaped by multiple glacial advances during the last 14,000 years. These processes greatly post-date and are unrelated to the processes that resulted in the deposition of the layers of sedimentary rock that form the bedrock of this region, and there is a great gap in the geological record from the deposition of Pennsylvanian sediments that became sedimentary rocks to the deposition by glaciers of the surficial sediments.

iii. Possible questions or prompts to ask: What glacial deposits are found in your home county?



Can you relate the occurrence of these surficial deposits to any economic activity in your county (e.g., gravel pits, recreational areas, agricultural use, etc.)

What is the relationship of the bedrock geology map and surficial geology map of your state?

Using the two maps (bedrock geology and surficial geology), tell the story of Michigan/Ohio’s geologic history.

c) Notes on potential misconceptions: [Michigan]: there is a wide-spread misconception that the weight of the glaciers caused

(formed) the Michigan Basin, confusing isostatic adjustment with tectonic (structural) deformation. The glaciers are responsible for depressing the crust, but NOT for structural deformation that folded the Paleozoic strata into the doubly-plunging syncline (basin). The Michigan Basin formed during the Paleozoic Era as the result of crustal stresses related to the Taconic, Acadian and Alleghenian orogenies.

d) Concerns to look for: Indication of the phenonomon of past glaciation as “just a theory”, incredulity that great

ice sheets covered the midwest

e) Power Point notes: Pleistocene geology.ppt

Handouts for Participants: Activity Guide #4.3, Surficial geology maps of Ohio and MichiganReferencesEmbedded Assessments Are teachers able to identify different types of glacial deposits? Can teachers use this evidence to explain current topography and land use?MI & OH Benchmarks AddressedMichigan

EG.V.1 1. Describe and identify surface features using maps. EG.V.1 MS4. Explain how rocks and fossils are used to understand the age and

geological history of the earth. EG.V.1 MS3. Explain how rocks are broken down, how soil is formed and how surface




Systems & EnergyThis activity helps participants understand the organization of the geosphere and hydrosphere. Elements of Inquiry1. Learners engage in scientifically oriented questions.2. Learners give priority to evidence in responding to questions3. Learners formulate explanations from evidence



4. Learners connect explanations to scientific knowledge5. Learners communicate and justify explanations

5E ModelEngage – What are the most recent changes?Explore – Use maps to identify ice advances and retreatsExplain – Explain the current surface topography and geologyElaborate – Put all of the pieces together to tell the complete geologic story for the past 500 million years.

ACTIVITY # 4.4: Post-Assessment

Purpose and Goals of the activity: To document changes in participant content knowledge during the mini-course.Estimated time to complete the activity: 30 minutesMaterials list: Copies of Assessment for each participantAdvance preparation notes: Make sure copies of assessment are readyDetailed procedure:

Facilitator hands out assessment, collects them at the end of 30 minutes (or some reasonable amount of time depending on the dynamics of the particular group of participants).

Facilitators should lead a whole class discussion to informally Identify areas of strengths. Identify areas of weakness. Identify old questions that may not have been answered Identify new questions that may have arisen as a result of the course



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