Iapetus Ocean Presented by Christina Hurley

Introduction What What When When How How Closer Closer Evidence Evidence Conclusion Conclusion

What? Ancient ocean Ancient ocean –located between Laurentia and Baltica Precursor of Atlantic Ocean Precursor of Atlantic Ocean –Iapetus = Greek titan, father of Atlas Atlantic Ocean named after Atlas Atlantic Ocean named after Atlas

When? Dates range from ~ mya Dates range from ~ mya Most agree on 750 mya for when it opened Most agree on 750 mya for when it opened

How? Laurentia and Baltica were part of Rodinia Laurentia and Baltica were part of Rodinia Suture zone between the two land masses became weak Suture zone between the two land masses became weak Upswelling caused rifting Upswelling caused rifting

Everything comes to an end Wilson Cycle Wilson Cycle –pulling turned into compression Island arcs formed Island arcs formed Taconian Orogeny Taconian Orogeny –Island arcs thrust upon Laurentia Formed New England and Appalachian Mountains Formed New England and Appalachian Mountains

Did it really exist? Huff Huff –people said it never existed North and South America used to be next to each other – no room for Iapetus North and South America used to be next to each other – no room for Iapetus –Ash beds and fossils prove it –Studied the ash beds, do not correlate Composition changed Composition changed –Indicates moving around –Fossils came from same area Piece broke off and relocated with South America Piece broke off and relocated with South America

Rankin Rankin –Studied Appalachian Mountains –Piedmont province Pieces of Africa – evidence of suturing and ripping apart Pieces of Africa – evidence of suturing and ripping apart –Bends in mountains Evidence of triple junctions Evidence of triple junctions 5 bends show possible triple junctions affected by hot plumes of magma 5 bends show possible triple junctions affected by hot plumes of magma 2 southwestern Virginia; 1 southeastern New York; 1 southern Quebec 2 southwestern Virginia; 1 southeastern New York; 1 southern Quebec

Conclusion Iapetus Ocean formed 750 mya when Rodinia broke up Iapetus Ocean formed 750 mya when Rodinia broke up Wilson Cycle closed it up Wilson Cycle closed it up Evidence of existence: non-correlating ash beds, pieces of Africa in Appalachian Mountains, bends throughout matching triple junctions of Rodinia Evidence of existence: non-correlating ash beds, pieces of Africa in Appalachian Mountains, bends throughout matching triple junctions of Rodinia