12 - bottom Similarly the magma that has risen spreads out beneath the plates As the magma spreads out the plates are dragged along and they move

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17:33 The Worlds Ocean Floor Arthur Holmes 1930s  Convection Cooler stuff sinks, hot rises Earth heating up as you go down (30 degrees) Idea for why the Continents drifted: It is possible for the plates to move due to the  convection currents  in the mantle.  The movement of these currents is similar to  the movement of convection currents in a beaker of boiling water. Convection – the heat from the interior of the earth trying to get out (driving force) Water that has risen spreads out across the surface, cools and sinks to the 
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Unformatted text preview: bottom. Similarly, the magma that has risen spreads out beneath the plates . As the magma spreads out, the plates are dragged along and they move away from each other. This is the process of sea-floor spreading . *Coastline does not equal limit of continental lithosphere of edge of continental shelf Sir Edward Bullard – 1965 continental fit based on the 1000m contour Paleomagnetism – a new way to analyze Earth’s history – 1950’s-1960’s Iron fillings scattered around a bar magnet 17:33 17:33...
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This note was uploaded on 10/06/2010 for the course GEOL 240Lxg at USC.

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12 - bottom Similarly the magma that has risen spreads out beneath the plates As the magma spreads out the plates are dragged along and they move

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