Iapetus OceanIapetus Ocean

Presented byPresented by

Christina HurleyChristina Hurley

IntroductionIntroduction

• WhatWhat

• WhenWhen

• HowHow

• CloserCloser

• EvidenceEvidence

• ConclusionConclusion

What?What?

• Ancient ocean Ancient ocean – located between Laurentia and Balticalocated between Laurentia and Baltica

• Precursor of Atlantic OceanPrecursor of Atlantic Ocean– Iapetus = Greek titan, father of AtlasIapetus = Greek titan, father of Atlas

•Atlantic Ocean named after AtlasAtlantic Ocean named after Atlas

When?When?

• Dates range from Dates range from ~500-750 mya~500-750 mya

• Most agree on 750 Most agree on 750 mya for when it mya for when it openedopened

How?How?

• Laurentia and Laurentia and Baltica were part of Baltica were part of RodiniaRodinia

• Suture zone Suture zone between the two between the two land masses land masses became weakbecame weak

• Upswelling caused Upswelling caused riftingrifting

Everything comes to an endEverything comes to an end

• Wilson CycleWilson Cycle– pulling turned into compressionpulling turned into compression

• Island arcs formedIsland arcs formed

• Taconian OrogenyTaconian Orogeny– Island arcs thrust upon LaurentiaIsland arcs thrust upon Laurentia

•Formed New England and Appalachian Formed New England and Appalachian MountainsMountains

Did it really exist?Did it really exist?

• HuffHuff– people said it never existedpeople said it never existed

•North and South America used to be next to North and South America used to be next to each other – no room for Iapetuseach other – no room for Iapetus

– Ash beds and fossils prove itAsh beds and fossils prove it

– Studied the ash beds, do not correlateStudied the ash beds, do not correlate•Composition changedComposition changed

– Indicates moving aroundIndicates moving around

– Fossils came from same areaFossils came from same area•Piece broke off and relocated with South Piece broke off and relocated with South

AmericaAmerica

• RankinRankin– Studied Appalachian MountainsStudied Appalachian Mountains– Piedmont provincePiedmont province

•Pieces of Africa – evidence of suturing and Pieces of Africa – evidence of suturing and ripping apartripping apart

– Bends in mountainsBends in mountains•Evidence of triple junctionsEvidence of triple junctions

•5 bends show possible triple junctions 5 bends show possible triple junctions affected by hot plumes of magmaaffected by hot plumes of magma

•2 southwestern Virginia; 1 southeastern New 2 southwestern Virginia; 1 southeastern New York; 1 southern Quebec York; 1 southern Quebec

ConclusionConclusion

• Iapetus Ocean formed 750 mya when Iapetus Ocean formed 750 mya when Rodinia broke upRodinia broke up

• Wilson Cycle closed it upWilson Cycle closed it up

• Evidence of existence: non-Evidence of existence: non-correlating ash beds, pieces of Africa correlating ash beds, pieces of Africa in Appalachian Mountains, bends in Appalachian Mountains, bends throughout matching triple junctions throughout matching triple junctions of Rodiniaof Rodinia