Geo 100 Notes jan 29

Geo 100 Notes jan 29 - -Spreading centers are offset by...

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Geo 100 Notes 1/29/08 -Break up of Africa and N America ~180 Ma. -Australia and Antartica, Africa and Antartica, Arabia and Africa have seafloor age symmetries -13 rigid plates in the Lithosphere, a bunch of smaller plates in asthenosphere -At transform fault boundaries , plates slide horizontally past eachother -At divergent boundaries , plates move apart and create new lithosphere -At convergent boundaries , plates collide and one is pulled into the mantle and recycled Divergent Plate boundaries: -oceanic plate separation -Rifting and spreading along narrow zone created mid-Atlantic ridge, a mid ocean mountain chain where volcanoes and earthquakes are concentrated -oscillating pattern of magnetic field strength, alternating bands of high on low magnetism symmetric on both sides of ridge Transform Fault Boundaries:
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Unformatted text preview: -Spreading centers are offset by mid-ocean ridge transform faults, where the two oceanic plates slide horizontally past each other-San Andreas is the continental curst transform fault, even though it isnt technically one Convergent Plate Boundaries:-Subduction, one plate slips below the other-Neither goes down, mountain building-When two oceanic plates converge they form a deep sea trench and a volcanic island arc-Continent continent collision, when two continental plates collide, the crust crumples and thickens, creating high mountains and a wide plateau-plates move over hot spots, and then it erupts making island chains-plates move by convection, move between 1-200mm per year-continents move with oceanic crust, not through it, that is why plate techtonics and continental drift differ...
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This note was uploaded on 03/27/2008 for the course GEO 100 taught by Professor Demets during the Spring '08 term at Wisconsin.

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