Lecture 2 (September 2)

Lecture 2 (September 2) - South America and Africa were...

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South America and Africa were stuck together for the first 60 million years the Atlantic Ocean was opening The Red Sea started opening 10 million years ago East African Rift: trying to form a new continent and ocean basin (same thing happened to Madagascar 100 million years ago) Olduvai Gorge Niger Failed Rift Arm (aulochogene): northwest Africa from central Africa o Usually 2 of the arms work and one of them fails o Diagram in Notebook Intra-Plate Earthquakes: rare but sometimes large o New Madrid, MO: three large eqs (M7-&7.5) Winter 1811 – 1812 (weird place, in middle of continent) o The largest that have ever struck the U.S. (clearly nonsense) 500 million years ago there is a failed rift arm where the Mississippi River (that’s why there’s a low point, the crust is weak) Convergent Boundaries: basically surround the Pacific everywhere except California Diagram in Notebook: Subduction Zones Volcanoes occur always nearly right above where the slab hits the 125 km depth
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This note was uploaded on 01/27/2009 for the course GEOL 240Lxg taught by Professor 12:30-01:50pm during the Fall '07 term at USC.

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Lecture 2 (September 2) - South America and Africa were...

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