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ABSTRACTCrustal Evolution Education Project (CEEP) modules

were designed to: (1) provide students with the methods and resultsof continuing investigations into the composition, history, andprocesses of the earth's crust and the application of this knowledgeto man's activities and (2) to be used by teachers with little or noprevious background in the modern theories of sea-floor spreading,'continental drift, and plate tectonics. Each module consists of twobooklets: a teagher's guide and student investigation. The teacher'sguide contains all of the inf,ormation present in the studentinvestigation bookletas well as: (1)'a general introduction; (2)prerequisite student backgromid; (3) objectives; (4) list of requiredmaterials"; (5) background information; (6) suggested approach; (7)procedure, recommending two -three 45-minute class periods required;(8) summary questions (with answers); (9) extension activities; and/(10) list of references..Best used after condeptS of continentaldrift, sea-floor spreading, and plate tectonics are introduced,,_ =

students study rocks found in areas thought to be former portions of,the proto-continent of Gondwanaland, learning what rocks reveal aboutthe environment, correlating'rockrunits using fossil eVidenc6, using.superposition prinCiple to find relative ages of yo units, anddescribing evidence supporting theoryhat contine s were oncejoined.-iAuthor/JN)

DOCUMENT RESUMEI

, SE 038 1234

Stoever, Edward C., Jr.Fossils as Clues to Ancient Continents. CrustalEvaluation Education Project. Teactier's,Guide [and]Studett Investigation.National Association of Geology Teachers,.National Science Foundation, .Washington, D.C.CEEP-MOD-OH9-8-8; ISBN-0-89873-014-7;ISBN-0-89873-015-579SED-75-20151; SED-77-08539; SED-78-2510431p.Ward's Natura,1 Science Establishment, Inc:, P.O. Box1712, Rochester, NY 14603 (or P.O. Box 174a,Monterey, gp, 93940.)

H701 Plus/ Postage. PC Not Available from EDRS.*Earth aciencev.,Geology; Instructional Materials;Oceanography; *Paleontology; *Science Activities;*Science Course Improvement Projects; ScienceCurriculum; Aience Education; Science Instruction;Secondary Education; *Secondary School Science;Teaching Guides; Teaching MethodsContinental Drift; *Crustal Evolution EducationProject; National Science Foundation; *PlateTectonics 4

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Reproductiops supplied by EDRS'are the best that can be madefrom the original document.

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NAGT Crustal Evolution Education ProjectEdward C. Stoever, Jr., Project Director

Welcome to the exciting world of current researchinto tne composition history and processes of theearth s crust and the application of this knowledgeto ran s activities The earth sciences arecurrently experiencing a dramatic revolution inour understanding of the way in which the earth.corks CEEP modules are designed to bring intothe classroom the methods and results of thesecon,nuincl investigations The Crustal EvolutionEl:cation Project began work in 1974 underthe ausoices of the National Association ofGeology Teachers CEEP materials have beende.'elope.d by teams of science educatorsc;assroom teachers and scientists Prior tor ,r)i,catiorgettle materials were field tested oy

5rP nan 200 teachers and over 12,000 studentsC iveht :_r_.sta: evolution research is d breaking

story -a' s'..de nts are living through today

*About CEEP ModulesCEEP --odules consist 9f two bookle,ts a

Teac-er s G. le and a Student Investigation TheTeacher s contains allthe informationand ili,s'rations in tne Student jnyestigation

:s sections printed in color intended only for therear _ aS .'re" as answers to the questions tnatare inc ded n !n--- Student Investigation

some mod,illes nere are illustrations that,1:-.)pear Ondi ire TeaCner s Guide and these are-:es l'aect cy ietters instead of the numbersed .nice used in the Student Investigation

Jr SO-Te mod ,,es 'ThaDS rulers and otherr_.,as-sroom mater.ais are needed and in

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Trie material was prepared with'ftbesupport of National Science FoundationGrant Nos SED 75 20151, SED 77-08539and SED 78 25104 However any opinionsfindings corclusions or recommendations ff",eyoressed herein are those of the author(s)and do no' rlcessanly reflect the viewsoNSF

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in oiler io corn', with U S PurIliC Lawever; sch-_,.". district in the U S A

using these materialS agrees to make'them available for inspection by parents orguardians of children engaged ineducational programs or projects of theSchool dittrict

6Copyright 1979 byouttionst Missouri State University

Teachers and students alike have a unique'opportunity through CEEP modules to share in theunfolding of these educationally important andexciting advances CEEP modules are designedto provide students with appealing firsthandinvestigative experiences with concepts which areat or close to the frontiers of scientific inquiry intoplate tectonics Furthermore the CEEP (nodules G

are designed to be used by teachers with little orno previous background in the modern theoriesof sea-floor spreading continental drift and platetectonics

We know that you will enjoy using CEEPnnodures in your classroom Read on ano beprepared to experience a renewed enthusiasm forteaching as you learn more about fee living earth.r 'nis and other CEEP modules

.arving quantities according to, tne method ofPresentation Read over the rio1,1,e beforesc^eciuli^g its use in class and refer to the list ofmiaTERIALS .n the moduie

Each module is individual and se's- contained in-ntent put so 6'. are divided into tvvo or more

carts for ri,,Dheh:ience The recor-m? -Jaci.,d lengtheach module is indicated Some module5

pr.-requisite knowledge ut some aspectsn ras,c earth science t^ls is notti'_71 in theTeacher s Guide

I

r'

NAGT Crustal Evolution Education ProjectEdward C. Stoever, Jr., Project Director

Welcome to the exciting world of current researchinto the composition history and processes of theearth s crust and the application of this knowledgeto r' an s activities The earth sciences arecurrently experiencing a dramatic revolution inour understanding of the way in which the earthworks CEEP modules are designed to bring intothe classroom the methods and results of thesecontinuing investigations The CrUstal EvolutionElu'i.ation Project began work in 1974 underthe auspices of the National Association ofGeoiogy Teachers CEEP materials have beende,.eloped by teams of science educatOrsc.assroorr, teachers and scientists Prior to

.-)hcatiorfe the materials were field tested by'-'1,re than 200 teacners and over 12 000 students

C-2Lrrert :'_staff evolOtion research is d breakingt-a 31der-ts are living through today

About CEEP Modules ...Mos' CEEP modules consist 9f two booklets aTeacher s Gu ^e an':!, a Student Investigation TheTea r''A'r conta,ns ah_the information

,sfratio^s I^ the Student jnvestigations sect' ins printed it color intended only for the

teacrer as we, as answers to the questions tnatare ^r ,ded n tne Student Investigation

soe rf-odules mere are illustrations that,hpear 'Dn'y 'n the Teachers Guide and these are

des Tra,--2 by f,gJre. ,ette.rs instead of the number,Sel ^ the Stjdert Investigation

s-Je mioh.,u,es as rulers and otherassroom materrals are needed and in

r

material was prepared witttpes.apport of National Science FoundationGrant Nos SED 75 20151 SED 77-08539and SED 78-25104 However any opinionsfindings cop elusions or recommendations 4-e4re,ssed herein are those of the authorfs)and 10 not necessarily reflect the viewsor NSF

order to comply with U S Put?lic Law94 86 e'er/ '_-Lstrict in the U Susing these materials agrees to make

'them available for inspection by parents orguardians of children engaged inechleatIonal programs or projects of theschool di"Strict

Copyright 1979 tryouthesst MissOuri State University

Teachers and stucints alike have a uniqueopportunity through CEEP modules to share in theunfolding of these educationally important andexciting advances CEEP modules are designedto provide students with appealing firsthandinvestigative experiences with concepts which areat or close to the frontiers of scientific inquiry intoPlate tectonics Furthermore the CEEP lnodulesare designed to be used by teachers with little orno pre.ious background in the modern theoriesof sea-floor spreading continental draft and platetectonics

We know that you will enjoy using CEEPmodures in your classroom Read on and beprepared to experience a renewed enthusiasm forteaching as you learn more about fhe hying earthr tims and other CEEP modules

quantities according to the method ofPresentation Read over the module beforescheduling its ise in class and refer to tne list ofMATER11-',LS in the module

Each module is individual and serf- contained insore are diyided into two or more

or ry-in,;E:nier,ci, The recornmrded lengtht f(:), each -nodule is indicated Some modules, r pr-requisite knwiedge D4 some aspects

f r,sic, eartn science -tnis IS n'itCI in theTeaohers Guide

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Fossils As Clues ToAncient Continents=

INTRODUCTIONIn 1915, German meteorologist Alfred Wegenerbased his theory of continental drift on evidence inrocks from several continents.. The ancientclimates indicated by the_rocks were quite differ-entfrom the climates thV prevail'in thesejYreSent-day continents oE countries. For example,evidence was _found for glaciation in Indiaduring Permian times

In these activities, students study rocks found inareas thought to be former portions.of the proto-continent of Gondwanaland. They learn whatrocks can reveal about the environment. By usingfossil symbols, they correlate rock columns andfind that environments during the Paleozoicand early Mesozoic were similai in four nowwidely separated areas. They learn how the dis-tribution of certain fossils contributes to theconcept of continental drift.

PREREQUISITE STUDENT BACKGROUNDThis module is best used after the conceptsofcontinental drift,ssea-floor spreading and plate-tectonics have been introduced. Students should%be familiar with the major rock types, the geologictime scale and the prindiples of superpositionand correlation. They should alsobe/able toidentify. the continents on an outline map of theworld. In introducing the activity, you shoulddiscuss uniformitarianism and its role indeciphering the earth's geologic history.

In the early 190ds, a famous English explorer, 'Captain Robert Sc Ott, made a surprising discoverywhen exploring the cold and forbidding continentof Antarctica. Captain Scott describes the dis-covery in his diary in this entry for February8, 1912 s .

."We found ourselves under perpendicularcliffs k f Beacon sandstone, weatheringra idly okcarrying veritable coal seamsF om the !At, Wilson, with his sharp eyes,has picked several plant impressions, thebest a piece of coal with beautifully tracedleaves in layers, also some excellentlypreserved impressions of thick stems,showing cellular structure

This was written upon Scott s return from theSouth Pole The co& seams and plant fossils hadbeen found at the base of Mount Bowers, atthe Wad of the Beardmore Glacier

Geologists generally suppose that coal is formedin temperate or tropical regions How could it have

,formed in Antarctica; which is now althostentirely covered by glacial ice?

OBJECTIVES --After you have completed,these activities, youshould be able to1. Tell how rocks indicate the environment inwhich they were formed..2. Use superpositiOn to find th# relative ages ofrock units.3.' Use foSsils to correlate rock ufuls. .

4: Describe evidence which supports the theorythat certain'continents were once joined.

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MATERIALSColored pencils /Geologic time scale (such as foilnd in your earth

-science text or reference books) and a politicalworld map would be helpful.

Each student group should have a set of six rocks:basaltic lava, marine sandstone, fluvial sand-stone, shale, tillite, an5 coal. The fluvial sandstoneshould be poorly sorted,. relative to the marinesandstone. The tillite will be the most difficultto obtain. However, you could substitute thecemented till found in many places in the Midwest.Otherwise, a conglomerate with some angulargrains can be used.

BACKGROUND INFORMATION 4

The data for the stratigraphic columns andthe correlations provided in this teacher guidewere generalized from the article cited below.The authors of the activity added data onLystrosaurus. This information is highlygeneralized and simplified so that it will be moreunderstandable to shit:lents. Despite this, studentswill be able to infer the same correlationsagreed upon by the scientists.

Grindley, G.W., 1963, The geology of the QueenAlexandra Range, Beardmore Glacier, RossDependency, Antarctica; with notes on the corre-lation of Gondwana sequehces. New Zealand .

Journal of Geology and Geophysics, v. 6,(June}, p. 307-347.

SUGGESTED APPR ACHThis activity is written in a step-by-step, indi-vidualized format. Man students can use it in anindependent study situation. However, you caneasilti adaprit for total-class, laboratory-typeteaching situations. The introductory questions,objectives, and jhe explanatory and summaryinformation could be presented in pre-lab andpost-lab group discussions. In either case,students can work in teams of two.

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PROCEDUREPART What can we learn from rocks aboutpast environments?

Students learn about the past environments offour areas by studying the characteristics oftheir rocks. You should emphasize the principleof uniformitarianism (that we judge the past,by the present.)Aey words: fluvial, marine, tilliteTime required: one 45- minute periodMaterials: six different rocks

/I:geologist is a scientist who studies rocks tolearn about the history of the earth Your teacherwill provide yoy with six rocks that haftbeen identified and described by geolOgists.

1. Identify each of your rocks You'or your groupwill have one of each of the following:

Basaltic lava was formed from molten rock thaterupted from volcanoes or from long cracks inthe earth's crust. It is dark and so fine-grained thatyou will not be ableo see individual grainsIt may have round holes formed ray gases releasedfrom the molten rock and then trapped in thelava as it hardened.

Marine sandstone was formed from sedimentsdeposited in a sea or ocean Usually it will containonly qvartz grains. Individual grains will all beof about the same size Any fossils It may containusually will be of plants or animals that lived in saltyiater

Fluvial sandstone was°formed from sedimentsdep9sited in the bed of a stream. It may haveminerals other than quartz, and the mineral grainswill be of various sizes If there are any fossils,they will be of plants or animals from on landor in freshwater. .

Shale is a very fine-grained rock formed fromclayor mud. It will show some layering.

Tillite is:a_rock fanned from sedltnpnt depositedby a glacier. These rocks may have a wide varietyofgrain sizes and minerals. Many of the grains willbe somewhat angular

Coal is formed Jrom the remains of treesother prantslhat grew in swamps. Coal willbe Nat*. brittle, and riot very' hard. It may havefossilized leaves and plant efems.

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Time Scale/ Meters

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1500

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2. After you haVe identified all six rocks, placeeach one on Worksheet 3 on the correct symbol`krepresenting that rock. Have your teacher checkyour,rqk identification before you continue withthe activity. Notice that each of the symbolson Worksheet 3 is used in the rock columnchart on Worl9heet 1. Remember what each sym-bol means and also the kinds of conditions underwhich each type of sediment or rock materialwas deposited.The purpose of this tep is for students to becomefamiliar with the symbols used for certain rocktypes on Worksheet 1 and with the idea that rocksCan reveal to the geologist the environmentsin which they begac to form.3. Apply theiprinciple of superposition to theSouth Africa rock column on Worksheet 1 Whichrock layer is the oldest? marine sandstoneWhich layer is the youngest'? basalt

4. What was the environme91 of Antarctica likewhen the marine sandstone sediment was beingdeposited?Shallow seas must have covered Antarctica whenthe marine sandstone sediment was deposited.

What was the environment like when the coalmaterial was being deposited?Coal is generally thought to indicate a moistclimate with the r.emains of luxuriant vegetation

accumulating in swamps.5. Does the present environment in Antarctica

/ differ from either of those you describe in question- 4 above'? `leg If so, how does it differ'?

Today Antarctica is cold, arid and large0 covered,by glaciers.Could coal be forming in Antarctica today'? No

6. Locate India on the world map. What type ofclimate do.you thirik India has today'?You may need to discuss this with your students.Inform them that India has a climate that is

.wafm throughout the year, with heavy rainsduring the monsoon season.

7. Now examine the rock column from India.Could rocks similar to thoge represented by therock columns be forming in India today? YesWhich ones? 4.100

All of them could form, except Unite.Could tillite be forming today in India*?The one rock that is definitely not forming inIndia today is finite. Glaciers would be found onlyin the Himalayas. The rocks in this rock column"were found farther south and over an extens vearea. They imply that almost the entire coun ry

was covered by ice. A similar environment is'pofpossible in India today because of its proximityto the equStor.

8. You have observed that both India and Antarc-tica have rocks that were formed in ertvironmentsthat were much different from the environmentsin those two places today List as many explana-tion as you can, to account fdr this situation -"Thp m /or idea that the students should under-stand nowj.s that at another time the environmentsin both cohtinents were quite different fromtoday. Some students may suggest that the conti-nents have moved in or out of pdtar regions toaccount for the widespread glaciation.9. Examineithe rock'columns from all four ar s.

List each similar order of rock layersIhat youjanfindAll have tillite, shale, coal, fluvial sandstone andbasalt in that order from bottom to fop.,

10. qne similarity that you will have noticedis the presence of basalt at the top of each of therock columns How is basalt formed'?Basalt is an igneous rock-forrrled from magma.The basalts represented in these columnsconsist of lava flows.11. Can yoo tell 'whether the basalt in each of theareas was formed at the same time'? No .

ExplainHow about the coal'? No Explain.

With the available information, students cannotdetermine if the basalts were form,ed at the sametime or if the coals were formed at the sametime. More information is needed. This pointshould be emphasized. Because similar rocks wereformed in similar environment* does not neces-sarily mean the rocks are the same age.

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PROCEDURE pownstrR.,-PART B: How old are the rockg?Students date the rocks in the rock columns byusing fossils. They then correlate the rock unitsand find that the four areas had simileen-vironments at each time interval, up until the endof the Triassic Period, when the environmentsbeg apf44:5 differ.

Key words: correlation, Glossopterls,Lystrosaurus, Dicroldium, radiometric dating,.GondwanalandTime required: one 45-minute periodMaterials colored pencils, political map of the

(world

You found out in step 11, PART A, tharyou reallycould not tell from the information provided,whether layers of similar rock types from differentareas were formed at the same time. if you couldfind ourthe ages of these rocks, then you Goulddetermine whether the same environment existedin all four areas at the same time. You couldalso leant whether the environment changed inthe same Way in each of the four areas. This wouldcertainly tell ids something interesting aboutthe history of the areas.

To determine the age of a sedimentary rock, wemust find fossils. Certain fossil species are alwaysthe same age wherever they occur All rockscontaining these fossils are thE same age even iffound in different places and even if they aredifferent kinds of rocks Matching the agesof rocks is known as correlation.

The plant fossils foLind bk.Scott's expedition havebeen rdentifibd by geologists as Glossoptarls.These plants have been found in coal seams inmany places around the world. Glossopteris is ofPermian age.

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Figure 1. Leaf of the Glossopteris plant, whichlived during the Permian age, 270 million years' ,

ago. (Redrawn from Hurley, P.f4.1., 1968, ScientificAmerican) `

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1. The rock columns are from four different areas.Antarctica, India, Brazil and South Africa. Writethe names of these areas in their proper places onthe outline map-of the world (Worksheet 2).See Answer Sheet 2

2. Color in each time period in the Time Scale,on the left edge of the rock columns chart (Work-sheet 1), with a different color. (Th9se six dis-tinctive colors will then be used Wer to Mark thesame ages orkthe four rock columns.) Color inthe beds contnifig the Glossopteris fosslIS withthe color you used for Late Carboniferous orPermian on the Time Scale. Place a "G" on yourworld map (Worksheet 2) where Glossopteris hasbeen found, next to the names of the fourareas located in step 1.See Answer Sheet 2Have the students all use the syme color codescheme.

3. How can you explain the presence of Glossop-tens in four such widely separated areas?Supporters of continental drift have used thepresence of Glossopteris as evidence of the formercontiguity of the four areas. They argue thatthe plant could not have migrated over such ex-tensive areas of the ocean. Opponents,'however,suggest that seeds Could have been carried byocean curre* or maybe the wind. This typeof migration accounts for the presence ofthe native flora and fauna of volcanic islands suchas the Howaiian Islands. You will need to helpyour students arrive at explanations for the'presence of Glossopteris.

4. Fossilized 011ien found in the tillites indicatesthat they are either Late Carboniferous or EarlyPermian Color in the tillites with the coloryou used for that age in the Time Scale.The students will be using the same color as instep 2. This is because the age ranges of theppllen and that of the Glossopteris overlap duringLower Permian. Therefore, for the purpose ofthis activity, they are "lumped" together.

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, Answer Sheet 2 (PART B)

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In-1967, a geologist wttq'the Ohio State UniversityInstitute of poleStudies found a'jaw fragmentbelonging to 41 ancient amphibian, not far.irom

%where Scott's party found the coal -seams andthe GIcIssopteris fossils 'A'tearn from the Institute

.pf Polar Studies, encouraged by this fihd,,retufnedto the same area in 1969 with a specialist inidentifying 'fossil amphibians 'and reptileS. On the

...first day of the expedition,- the team's leader, DavidElliot, climbed a.bluffnear.the base camp. Hekiund a'n ancient stream chgrinel containing bonesand teeth. Eglwin H.'Colbert, the specialist in.amphibian and reptile fossils, identified aiaw-bOne he found tipere liter as being thet_ofLystrosaurus, a reptile previously found in Indiaand South Africa in rocks of-Early Triassic.age. Itwas a larid reptile, not adapted for swimminglong distances

5. In the rock columns, color those sedimentscontaining Lystrosaurus with the color you used inthe Time Scale indicating their age.

6. Place an "Li' on Worksheet 2 beside the namesof those areas where Lystrosaurus has been found.How can you explain the presence of a reptile, likeLystrosaurus, in such widely separated areas'?It is very diffibult to argue that a land reptile,such as Lystrosaurus, could have migrated acrossthe oceans to populate such widespread areas.When Lystrosaurus was I.:5(.1nd in Antarctica alongwith four other sPeciesof land reptiles, mostpaleontologists became convinced that conti-nental drift was a viable theory.

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Figure 2. Lystrosaurus was a reptile that lived inIndia and South Africa during the Early Triassicage. (Redrawn with perrpission, courtesy of EdwinH. Colbert) "

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7. Certain shells found in the manfie sandstonesof Brazil, Sou Africa and Antafctica have beendetermined to be of Devonian age. Color inthese portions orthe,rocttolumns with the appro-priate color DIcroldlum"is a plant fossil restrictedto the Late Triassic. Color in the portions of the

__rock columns containing Dicrotthum.

The age of igneous rock, such as the basalt atthe,top of each of the rock columns, can be deter-mined throUgh,a process called radiometricdating. In this procedure, the amounts of cell-amradiokfive elements/in the rock are measured

8. The basalts'in Brazil and India'are of Cre-taceous age In South Africa and Antarctica Iheyare from the Jurassic Period. Color'the basaltin the rock column's with the coldrs you used forthese ages in.the Time Scale.

92Now correlate the rock units for each area.Draw lines between the columns indicating therock boundaries between each of the ages Theline dividing the "basement" rock (pre-Devonian)from the Devonian as already been drawn. in

SouthAfric have alsobeen correlated Have""!for you The Earlys,las'sic layers of Brazil a

your teacher check your correlations before yipst,continue.It is essential that you check each of the corre-lations before students continue with the activity.You may want to collect and evaluate them.Hold a class discussion regarding how to correlatethe rock columns correctly.before allowingstudents to continue. See Answer Sheet 1.-Youcould make an overhead transparency of AnswerSheet 1 to project during post-activity discussion.

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19. During what age.wereoglaciers present in all,four areas?At the beginning of Late Carboniferous-Permian.Fossilized pollen indicaies_ltiat glaciation endedin Early Permian.

11. When were three of-the areas covered by -

the sea?Brazil, South Africa and Antarctica were coveredby the sea during the Devonian Period.

12. During what age did all four areas haveextensive swamps?Late Carboniferous- Permian. The presence ofGlossopteris indicates a Perini a. age for theswamps.

13: How can you explain that in the past theenvironments of these four areas, as indicated bytheirrockArere very similar when today theirerrironments are so different?Students should conclude that Oita evidence theyhave been studyJng suggests that these fourareas were part of a single continent from atleast Devonian through Jurassic.

In this activity you have studied some of theevidence that leads geologists to believe that atone tim India, Antarctica, Africa, Australia and

. South A erica were all part of one super-continent called Gondwanaland.

14. From your sSudy of plant and animal fossils,determine the most recent time that Goklwana-land could have been a sirigle continent 01I

Dlcroldlum is present in an four areas in Middleto Late Triassic. Therefore, the continents wereprobably together through the Triassic.

15. When did extensive volcanic activity firstoccur in Gondwanaland',Lava flows occurred during the Jurassic Periodin South Africa and Antarctica.

16. When do you think Gondwanaland began tobreak up?Studdnts might conclude that the extensivevolcanic activity indicated by the basalt at thetop of each column was daused by the Sreakup ofGondwanaland. If so, it must have started tobreak up during the Jurassic, with India and Brazilbreaking loose in the Cretaceous. Hold a post-labdiscussiod emphasizing the meaning of thecorrelations that the students have completed.The major purpose of the activity is to presentevidence of the former unity of the four areas. TheInformation provided by the rocks and fossilsis important evidence bearing upon platetectonic theory.

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SUMMARY QUESTIONS1. How do geologists determine the type ofenvironment that existed in an area during thepast?

Geologists determine the environm nt of an areasAtr the types of rocks and fossil hat arefound there.' .

2. A geologist found several layers of sedimentexposed in a river bank. Which was the oldestlayer? the youngest?Using the principle of superposition, the geologistwould determine that the lowest bed Aes theoldest and the highest bed was the yotingest.

REFERENCESCrawford, A,R., 1974, Great Gondwanaland.*

Science, v. 184, no. 4142 (June 14), p. 1179-1181.

1974, Final piece of the Gondwana game. ScienceNews, v 106, no 4 (July 27), p. 54.

1974, Geologists assemble the biggest puzzle ofall: Gondwanaland Science Digest, v. 76, no 4(Oct.), p. 72-73.

Lear, J., 1970, The bones of Coalsack Bluff.Saturday Review, v. 53, no 6 (Feb. 7), p. 47-51.

3. What is meartt by correlation of rock layers?Geologists can determine the age of a layer onthe basis of its fossils or by radiometric dating.They then can match (correlate) layers indifferent areas Where they-contain fossils of thesame age.

4. Describe the evidence for the former existenceof the continent Gondwanaland.Fossils and rocket found in the four different areasindicate that at ne time-the areas were joinedtogether.

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Worksheet 3 (PART A).

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NAGT, Crustal 'Evolution.EdubatiOn Project. ModulesCEEP Modures are listed here in alphabetical

.order. Each.MOGiule is designed for use inthe number of class,periods indicated. Forsuggested sequences of CEEP Modules tocover specific' topics and for correlationof CEEP Modules tp standard earth sciencetextbooks, consult Ward's descriptiveliterature.on CEEP The Catalog-Numbersshown here refer to the CLASS PACKof each Module consi,sling 9f a Teachers

-Guide and 30 copies:of-the/StudentIfives-tigation See Ward's desc6ptiveliterature for alternate order quanthies .

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iThryrig 1979 Except for the rights tO4-,atr.nals rc4servel ny, omers, ther 0-,1,sner and the copyright owner herebyTaro pormision without charge tO

4 1')^,oshr, persons of the LO S and Canada0. I SP of this Work and related materials

In Forltiln language in the U S andr-armia after 1985 For conditions Of use

pe,Mission to use the Work or any part'he.rnof for foreign publications or

,,-,er than the Engiish4' 1.11. Apo'', to Me copyright owner or

Diiroisher

CEEP ModuleClass CLASS PACK

Periods Catalog No.

A Sea-floor Mystery: Mapping, 3 34 W 1201Polarity Reversals

('Continents And Ocean Basins: 3-5 34 W 1202Floaters And Sinkers ,$

Crustal Movement; A Major Force 2-3 34 W 1203In Evolution

Deep Sea Trenches And Radioactive 1 ,34 W 1204Waste

Drifting Continents And Magnetic 3 34 W 1205Fields

Drifting Continents And Wandering 4 34 W 1206Poles

Earthquakes And Plate 2 34 W 1207Boundaries

Fossils As Clues To Ancient 1-3 34 W 1208Continents

Hot Spots In The Earth's Crust 3 34 W 1209

How Do Continents.Split Apart? 2 34 W 1210

How Do Scientists Decide Which Is 2 34 W 1211The Better Theory?

How Does Heat Flow Vary In The 2 34 W 1212Ocean Floor? ,,

How Fasels The Ocean Floor 2-3 34 W 1213Moving?

Iceland: The CascrOf The Splitting 3 34 W 1214Personality

Imaginary Continents: A Geologic& 2 34 W 1215Puzzle

Introduction To Lithospheric 1-2 34 W 1216Plate Boundaries

Lithospheric Plates And Ocean 2 34 W 1217Basin Topography

Locating Active Plate Boundaries 2-3 34 W 1218By Earthquake Data

Measuring Continental Drift: The 2 34 W 1219Lager Ranging Experiment

Microfossils, Sediments An4 4 34 W 1220Sea-floor Spreading

Movement Of The Pacific Ocean 2 34 W 1221Floor

Plate Boundaries And Earthquake 2 34 W 1222Predictions

Plotting The Shape Of The Ocean 2-3 34 W 1223Floor

Quake Estate (board game) 3 34 W 1224

Spreading Sea Mors And Fractured 2 34 W 1225Ridges

The Rise And Fall Of The Bering 2 34 W 1227Land Bridge

Tropics In Antarctica? 2 34 W 1228

Volcanoes; Where And Why? 2 34 W 1229

What Happens When Continents 2 34 W 1230Collide?

When A Piece Of A Continent 2 34 W 1231Breaks Off

Which Way Is North? 3 34 W 1232

.Why Does Sea Level Change? 2-3 ,34 W 1233

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Ward's Natural-Scienc_ Establishment, Inc.P.O. Box 1712, Rochoster, Now York 14603 . P.O. Box 1749, Monterey, California 93940

CUP MODULE NO. MN $4ISBN 046$73-014-7 is

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CRUSTALEVOLUTIONEDUCATION

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Student InvestigationCatalog No. 34W1108

Fossils As CluesTo Ancient Continents

DATE

INTRODUCTIONIn the early 1900s, a famous English explorer,Captain Robert Scott, made a surprising discoverywhen exploring the cold and forbidding continentof Antarctica Captain Scott describe-5 the dis-covery in his diary in this entry for February8, 1912

We found ourselves under perpendicularcliffs of Beacon sandstone, weatheringrapidly and carrying veritable co& seamsFrom the last, Wilson, with his sharp eyes,has picked several plant impressions, thebest a piece of coal with beautifully tracedleaves in layers, also some excellentlypreserved impressions of thick stems,showing cellular structure .."

OBJECTIVESAfter you have completed these activities, youshoufd be able to1. Tell how rocks indicate the environment inwhich 4i1iey were formed.2. -Use superposition to find the relative ages ofrock units3. Use fossils to correlate rock units.4. Describe evidence which supports the theorythat certain continents were once joined.

Copyright 1979 by Southeast Missouri slat. unirersit

This was written upon Scott's return from theSouth Pole The coal seams and plant fossils hadbeen foutrsid at the base of Mount Bowers, atthe head of the Beardmore Glacier---Geologists generally suppose that coal is formedin temperate or tropical regions How could it haveformed in Antarctica, which is now almostentirely covereAy glacial ice

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PROCEQURE --.

PART -)1, What can we learn from rocks aboutpast environments?Materials. six different rocks

.A geologist is a scientist who studies rocks tolearn about the history of the earth Your teacherWill provide you with six rocks that have

, been identified and described by geologists

1. Identify each of your rocks you or your groupwill have one of each of the following

Basaltic lava was formed from molten rock thaterupted from volcanoes or from long cracks inthe earth's crust It is dark and so fine-grained thatyou will not be able to see individual grains.It may have round holes formed by gases releasedfrom the molten rock and then trapped in thelava as it hardened.

Marine sandstone was formed from sedimentsdeposited in a sea or ocean Usually it will containonly quartz grains Individual grains will all beof about the same size. Any fossils it may containusually will be of plants of animals that lived in saltwater

Fluvial sandstone was formed from sedimentsdeposited in the bed of a stream It may haveminerals Other than quartz, and the mineral grainswill be of various sizes If there are any fossils,they will be of plants or animals from on landor in fresh water

Shale is a very fine-grained rock formed fromclay or mud. It will show some layering.

'Mite is a rock formed from sediment depositedby a glacier These rocks may have a wide varietyof grain sizes and minerals Many of the grains willbe somewhat angular

Coal is formed from the remains of trees andother plants that grew in swamps Coal willbe black, brittle, and not very hard It may havefossilized leaves and plant stems.

2. After you have identified all sik rocks, placeeaeh one on Worksheet 3 on the correct symbolrepresenting that rock. Have your teacher checkyour rock identifitatio_n ,before you continue withthe activity. Notice that each of the symbolson Worksheet 3 is used in the rock columnchart on Worksheet 1. Remember what each sym-bol means and also the kinds of conditions underwhich each type of sediment or rock materialwas deposited.

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3. Apply the principle Otsuperposition to theSouth Africa rock colurnri on Worksheet 1 Whichrock layer is the oldest?Which layer is the youngest"

4. What was the environment of Antarctica, likewhen the marine sandslone sediment was,:birtfirgdeposited"

What was the environment like _wheri the coalmaterial was being deposited?

5. Does the present environment in Antarcticadiffer from either of those you describe in question4 above" __ If so, how does it differ?.

CoCd coal be forming in Antarctica today"

6. Locate India on the world map What type ofclimate do you think India has today"

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Time Scale

Jurass!c.

MidOle-LateTnassic

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South Africa

India

Meters2000

Giossoptens

ystrosaurus

Drcrordium

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1500

1000

500

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7. Now examine the rock column from India. 9. Examine the rock columns from all four areas.Could rocks similar to those represented by the List each similar order of rock layers that you canrock columns be forming in India today? find.Which ones?

Could finite be forming today in India?

8. You have observed that both India and Antarc-tica have rocks that were formed in environmentsthat were much different from the environmentsin those two places today List as many explana-tions as you can, to account for this situation

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10. 0Qe similarity that you will have noticedis the presence of basalt at the top of each of therock columns How isfbasalt formed?

11. Can you tell whether the 4salt in each of theareas was formed at the same.iime?Explain .

HOW about the coal? Explain

PROCEDUREPART B. How old are the rocks?Materials colored pencils, polttical mapof theworld

You found out in step 11, PART A, that you real*/could not tell from the information provided,whether layers of similar rock types from differentareas were for*rneO at the same time. If you couldfind out the ages of these rock4, then you coulddetermine whether the same environment existedin all four areas at the same time You couldalso learn whether the environment changed inthe same way in each of the four areas. This Wouldcertainly tell us something interesting' aboutthe history of the areas.

To determine The age of a sedimentaly rock, wemust find fossils Certain fossil species are alwaysthe same age wherever they occur. All rockscontaining these fossils are the same age even iffound in different places and even if they aredifferent kinds of rocks. Matching the agesof rocks is known as correlation.

_The plant fossils found by Scott's expedition hatebeen identified by geologists as Glossopterls.These plants have been found in coal seams inmany places around the world Glossoptens, is ofPerlman age

,1. The ,rock Columns are from four different areasAntarctic, India, Brazil and South Africa. Writethe names of these areas in their proper places onthe outline map of the world (Worksheet 2).

2. Color in each time period in the---Trne Scale,on the left edge of the rock columns chart (Work-sheet 1), with a different color (These six dis-tinctive colors will then be used later to mark thesame ages on the four rock columns.) Color inthe beds containing the Glossopteris fossils withthe color you used for Late Carboniferous orPermian on the Time Scale. Place a "G" on yourworld map (Worksheet 2) where Glossopteris hasbeen found, next to the names of the fourareas located in step 1.

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3. How An you explain the presence of Glossop-tens in fOur such widely separated areas?

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4. Fossilized pollen found in the tillites irklicatesthat they are either Late Carboniferous or EarlyPermian Color in the tillites with the coloryou used for that age in the Time Scale

Figure Leaf of the Glossopterls plant, whichliyed during the Permian age, 270 million yearsago. (Redrawn fCom Hurley; P.M., 1968, ScientificAmerican)

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Worksheet 2 (PART B) ,,,

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In 1967, a geologist with the Ohio State University°Institute of Polar Studies found a jaw fragmentbelonging to an.ancient amphibian, not far fromwhere Scott's party found the coal seams andthe Glossopteris fossils. A team from the Instituteof Pola Studies, encouraged by this find, returnedto the same area in 1969 with a specialist inidentifying fossil amphibians and reptiles. On thefirst day of the expedition, the team's leader, DavidElliot, climbed a bluff near the base cam....Hefound an ancient stream channel containing bo9esand teeth. Edwin H. Colbert, the specialist inamphibian and reptile fossils, identified ajaw-bo9e he found there later as being that ofLystrosaurus, a reptile previously found in India .and South Africa in rocks of Early Triassic age. Itwas a land rep4th,ot adapted f or-swimminglong distances.

5. In the rock columns, color those sedimentscontaining Lystrosaurus with the color you used inthe Time Scale indicating their age

6. Place an "L" on Worksheet 2 beside thetnamespof those areas where Lystrosaurus has been foundJ-ow can you explain the'presencedof a reptile, likeLystrosaurus. in such wideiy separated areas?

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7. Certain shetts found in the marine sandstones.of-Brazil, South Africa and Antarctica have beendetermined to be of Devonian age Color 'inthese portions of the rock columns with the ahro-priate color Dicroldium is a Want fossil restrictedto the Late Triassic. Color in the portions of therock columns containing Dicrotchum.

The age of igneous rock, such as the basalt atthe top of each of the rock columns, can be deter-mined through a process called radiometric'dating. In this procedure, the amounts of certainradioactive elements in the rock are measured

8. The basalts in Brazil and India are 1:.)f Cre-taceous age. In South Africa and Antarctica theyare from the Jurassic Period. Color the basaltin the rock columns with the colors you used fortheie ages in the Time Scale.

9. NoW correlate the Mck units for each area.Draw lines between the columns indicating therock boundaries between each of the ages. Theline dividing the "basement" rock (pre-DeVonian)from the Devonian has already been drawn infor you The Early Triassic layers of Brazil andSouth Africa have also been correlated Haveyour teacher check your correlations before youcontinue.

Figure 2. Lystrosaurus was a reptile that lived inIndia and South -Africa during the Early Triasticage. (Redrawn with permission, courtesy of EdwinH. Colbert)

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10. During what age were glaciers present in'all,

In this activity. you have studied some of the 4four areas? evidence that leads geologists to believe that at

one time India/Antarctica, Africa, Australia andSouth AmencaNvere all part of one super-continent called Gondwanaland.

14. From your study of plant andlanimal fossils,determine the most recent time that Gondwana-land cduld have been a single continent.

11. When were three of fee areas covered bythe sea?

12. During what age did all four areas haveextensive swamps'? ,

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13. How can you explain that in the past theenvironments of these four areas, as indicated bytheir rocks, were 1ery similar when today theirenvironments are so different?

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15. When did extensive volcanic activity firstbccur in Gondwanaland?

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16. When do you think Gondwanaland began tobreak up?

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Woi*ksheet 3 (PART A)

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SUMMARY QUESTIONS1. How do geologists determine the type of'environment that existed in an area during thepast?

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2, A geologist found several layers of sedimentexposed in a river bank Which was the oldestlayer? the youngest?

3. What is meant by correlation of rock layers?

4. Describe the evidence for the former existenceof the continent Gondwanaland

REFERENCES

Crawford, A.R., 1974, Great Gondwanaland.Science, v. 184, no: 4142 (June 14), p 1179-1181

1974, Final piece o the Gond Wane game. ScienceNews, v. 106, no:}4 (July 27), p 54.

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1974, Geologists assemble the biggest puzzle ofall. Gondwanaland. Scien9'e Digest, v. 76, no. 4(Oct.), p 72-73.

Lear, J , 1970, The bones of Coilsack 151uffSaturday Review. v. 53, no 6 (Feb. 7), p. 47-51.

Developed byTHE NATIONAL ASSOCIATION OF GEOLOGY TEACHERS

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The material was prepared with the support ofNatrona! Science Foundation Grant Nos SED75-20151 SED 77-08539 and SED 78-25104However any opinions findings, conclusions, orreconimendations expressed herein are those of theauthor(s) and dmnot necessarily reflect the viewsof NSF

MARINWard's Natural Science Establishment, Ind: Rochester, NY Monterey, CA

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