Lecture 3 - Plate tectonics

Lecture 3 - Plate tectonics - Earth History 4.57 billion...

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4.57 billion years ago : formation of solar system and Earth Measured ages of oldest objects in Solar System (Moon rocks, meteorites) Oldest Earth rocks: 4.055 billion year old Canadian gneiss Oldest bits of rocks found on Earth: 4.4 billion year old zircon grains in Australian sandstone 3.9 billion years ago : large oceans, small continents 3.5 billion years ago : life (photosynthetic bacteria) 2.5 billion years ago : large continent 1.5 billion years ago : plate tectonics Earth History Earth History
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The Layered Earth The Layered Earth Differentiated into layers of increasing density Center of Earth: Iron-rich core core 3500 km in radius Inner core is solid and 1280 km in radius Outer core is liquid and has viscous convection currents , responsible for Earth’s magnetic field Surrounding core: 2,900 km thick mantle mantle Rocky in composition, dense Moho : boundary between mantle and crust Low-density (light) elements have been ‘sweated’ out of mantle to form crust crust , oceans oceans and atmosphere atmosphere
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The The Layered Layered Earth Earth Figure 2-10
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The Layered Earth The Layered Earth Figure 2-10
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The Layered The Layered Earth Earth Figure 2-10
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This note was uploaded on 05/17/2008 for the course GEO 107 taught by Professor Stidham during the Spring '08 term at SUNY Stony Brook.

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Lecture 3 - Plate tectonics - Earth History 4.57 billion...

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