Name:______________________________
Period:______
Date:_______________
LT1:Icananalyzeandinterpretdataonthedistributionoffossilsandrocks,continental
shapes,andseafloorstructurestoprovideevidenceofthepastplatemotions.
Part1:ContinentalDriftPuzzle
Intheearly1900s,CaptainRobertScott,whowasfromEngland,exploredthecontinentofAntarctica.Inhisjournal,hedescribed
findingplantfossils.ThesefossilswerelateridentifiedasGlossopteris(gloss-OP-ter-iss),anextinctfern-likeplantthatgrewon
earthabout250millionyearsago.Glossopterisgrewinwarm,wetareas,andcouldnothavesurvivedinanextremelycoldplace
likeAntarctica.HowdidthefossilsofthisplantendupinAntarctica?
Directions:
1. Withyourgroup,carefullyexaminethepuzzlepieces.CompareeachWorldPuzzlepiecetothecontinentson
themapthatMs.Towershasontheboard.
2. Workwithyourgrouptoarrangeyourpuzzlepiecesinlocationssimilartotheonesshownontheworldmap.
3. Lookatthesymbolsonsomeofthepieces.Thesymbolsrepresenttypesoffossilsorrocksfoundinseveral
locations.Theareasfollows:
Byabout300millionyearsago,auniquecommunityofplantshadevolvedknownasthe
Europeanflora.FossilsoftheseplantsarefoundinEuropeandotherareas.
FossilsofthefernGlossopterishavebeenfoundintheselocations.
Fossilremainsofthehalfmeter-longfreshorbrackishwater(reptile)Mesosaurus.Mesosaurs
flourishedintheearlyMesozoicEra,about240millionyearsago.Mesosaurshadlimbsfor
swimming,butcouldalsowalkonland.OtherfossilevidencefoundinrocksalongwithMesosaurs
indicatethattheylivedinlakesandcoastalbaysorestuaries.
FossilremainsofCynognathus,alandreptileapproximately3meterslongthatlived
duringtheEarlyMesozoicEra,about230millionyearsago.Itwasaweakswimmer.
FossilevidenceoftheEarlyMesozoic,land-dwellingreptileLystrosaurus.They
reproducedbylayingeggsonland.Inaddition,theiranatomysuggeststhattheseanimals
wereprobablyverypoorswimmers.
Alpinemountainrangescomposedofsimilarrockstrata(layers)
Groovedscratchesinrocksallpointedinthesamedirectionformedwhenlargeglaciers
scrapedacrossthelandscape.
4. Workwithyourgrouptotrytoplaceallofthepuzzlepiecesintoasingleshape.Worktogethertodecide
whereeachpiecebelongs.
Remembertolistentoandconsidertheexplanationsandideasoftheothermembersofyourgroup.Ifyou
disagreewithothermembersofyourgroup,explainwhyyoudisagree.
5. Inthespaceontheback,gluethepiecesofyourcompletedcontinentalpuzzletoshowhowthecontinents
oncefittogether.Labelthe“supercontinent”Pangaea.
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Part2:MakingthePiecesFit,TheEndlessVoyage
1.TRUEorFALSE
AlfredWegenerwasthefirstscientisttonoticethatthecoastlinesofAfricaand
SouthAmericaappeartofittogether.
2.Theideaofcontinentaldriftwasproposedby___Alfred Wegener_______________________.
3.TRUEorFALSE
SomeprominentscientistsofthetimefeltthatthefitofAfricaandSouth
AmericawasTOOgoodandthereforetheycouldnotpossiblyhaveoncebeen
connected.
4.TRUEorFALSE
Theideathatcontinentaldriftwasdrivenbyconvectioncurrentsactuallycame
aboutinthe1920s,notreallythe1960slikeourbooksays.
5.Geologistsfrom__the United States__moststronglydisagreedwithWegener.
6.WegenerwenttoGreenlandtomeasure___continental motion____.
7.TRUEorFALSE
BetweenWegenerandHess,therewerenoothergeologistsstudyingcontinental
drift.
8.DuringWWIIalotofnew______technology______wasdevelopedbecauseweneededtobeabletodetect
______metal_____underwater.
9.TRUEorFALSE
ThediscoveryoftheMid-AtlanticridgebyHarryHesswasnotenoughtoprove
Wegener’shypothesisofcontinentaldrift.
10.Inthe1960sscientiststestedrocksanddiscoveredthatrocksofthesameagehadthesame
______polarity/magnetic striping (orientation – North/South)_________.
11.Themagneticstripingontheseafloorislikea_____barcode / tape recorder____oftheEarth’smagneticreversals
overtime.
12.TheTheoryof_______Plate Tectonics___________wasoneofthemostpowerfulandunifyingtheoriesinthe
historyofscience.
13.___Trenches, earthquakes, and volcnoes___oftenoccurinsubductionzones.
14.Wearefurtherprovingthemovementofplatesbyusing______satellites__________whichareinafixedposition
inspace.
15.TRUEorFALSE
Thediscoveriesinvolvedinplatetectonicshadatremendouseffectontheway
othergeologicalscienceslookedattheirworld.
PostVideoReflectionQuestions
Inadditiontoevidencefrommapmakers,whatotherevidencewasdiscoveredthatsupportedtheideathat
continentswereonceconnectedtogether?
Fossils (plants and reptiles), rock formations, glacial scratches
AlfredWagner.WhatwashisideaaboutEarth’shistory?
That at one point in time all the continents had been joined forming one “super-continent” that he called Pangea.
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BaileyWilson.Whatwashisargumentagainstcontinentaldrift?
He argued that the fit of the continents was too perfect therefore the continents couldn’t possibly have broken apart.
Whatisthesocalled“ringoffire?”
The “ring” of volcanoes (and earthquakes) surrounding the Pacific Ocean
ExplainwhyWorldWarIIleadtoadvancesinourunderstandingofEarth’sgeology.
New technologies designed for detecting submarines allowed us to better understand the nature of the earth’s crust at the bottom of the
oceans
TheDeepSeaDrillingProjectplannedtotakerockcoresamplesfromtheAtlanticOcean.Whatdidtheyexpectto
observeinthesesamplesthatwouldsupportthetheoryofseafloorspreading?
The expected to see that the oldest samples would be farthest from the spreading ridge and getting younger the closer to the spreading
ridge.
HowcouldGPSbeusedtogatherevidencetofurthersupportthetheoryofseafloorspreading?
Can measure how much/fast a GPS marker on one side of an ocean moved in relation to a GPS marker on the other side of the same
ocean
Part3:PuzzlingEvidence
In1915,aGermanscientistnamedAlfredWegener(1880–1930)puttogetherseveralkindsofevidence—including
thelocationoffossilsandrocklayersondifferentcontinents—tocomeupwithanewideaaboutthehistoryofthe
continents.Hisideawasthatthecontinentswereoncejoinedtogethertoformasinglelargecontinentcalled
Pangea.Overgeologicaltime,Pangeasplitapartandpartsofitmovedawaytoformtoday’scontinents.Today,this
ideaiscalledcontinentaldrift.“Drift”referstotheideathatthecontinentsslowlymovedawayfromeachother,or
driftedapart.Inthisactivity,youwillexaminemoreevidenceforthismovementofcontinents.
Instructions
1. Carefullyreadoverthetableonthenextpage.
2. Discusswithyourgroupwhatisevidenceandwhatisnotevidence.
3. Readeachstatementcarefullyandthenmarkwhetheryouthinkitisorisnotevidence.Check“yes”ifyou
thinkitisevidence,and“no”ifyouthinkitisnotevidence.
4. Crossouteachstatementthatyouhavedecidedwasnotevidence.Youwillnolongerconsiderthese
statements.
5. Fortheremainingstatements,markwhetheryouthinkeachpieceofevidencedoesordoesnotsupportthe
ideathatcontinentshavemoved.Check“yes”ifyouthinkitsupportsit,and“no”ifyouthinkitdoesnot.
6. Withyourgroup,discuss:
a. whetheryouidentifiedastatementasevidenceornot.
b. howeachstatementyoucheckedasevidenceeithersupportsorcontradictstheideaofcontinental
movement.
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Isitevidence?
Yes
Statements
No
Doesitsupportthe
ideathatthe
continentshave
moved?
Yes
No
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1858:GeologistEduardSeusspointsoutthatfossilsoftheGlossopterisplantare
foundinsouthernAfrica,SouthAmerica,Australia,Antarctica,andIndia.
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Wegenerexaminesthelocationoftinyrocksandthedirectionofgroovesformed
bylargeglaciersscrapingacrosssouthernareasofAfrica,SouthAmerica,Australia,
Antarctica,andIndia.Heconcludesthatifalltheseplaceswerefittedtogether,
theywouldformacontinuousicesheetexpandingoutwardinalldirections.
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FrankfurtNews,January6,1912:AnnouncementthatGermanscientistAlfred
WegenerwillspeakattheGeologicalAssociationmeeting.
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PopularGeologymagazine,March12,1912:“Continentsaresolargetheymust
alwayshavebeenwheretheyare.”
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WegenerobservesthataSouthAmericanmountainrangeinArgentinalinesup
withanancientAfricanmountainrangeinSouthAfricawhenthetwocontinents
areplacedtogether.Hewrites:“Itisjustasifweweretorefitthetornpiecesofa
newspaperbymatchingtheiredgesandthencheckwhetherthelinesofprintran
smoothlyacross.Iftheydo,thereisnothingleftbuttoconcludethatthepieces
wereinfactjoinedinthisway.”
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1927:GeologistAlexanderduToitobservesrocklayersonthewesterncoastof
Africainthefollowingsequence:basaltrock,shalecontainingfossilreptiles,coal
layerscontainingGlossopterisfossils,rockscontainingMesosaurusfossils,and
shale.Hediscoversanalmostidenticalsequenceofrocklayersontheeasterncoast
ofSouthAmerica.
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1944:GeologistBailyWilliscallsWegener’stheoryafairytale.Hesaysitseems
impossiblethatthecontinentscouldmove.
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1965:GeologistEdwardBullardusescomputerstomatchcoastsofSouthAmerica
andAfrica.Theymatchextremelywellatanoceandepthof1,000meters.
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1980s:Satellitesandlasersareusedtomeasurethemovementofcontinents.They
continuetomoveatanaverageofabout2cm(0.8in)peryear.
✔
✔
FossilsofMegascolecinaearthwormsarefoundinSouthAmerica,Africa,India,and
Australia,aswellastheislandsofMadagascarandNewGuinea.
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SelfReflection:ColortheSmileyFacethatshowshowwellyoufeelyouunderstandLT#1
WhatHaveILearnedaboutLT#1:
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