Lecture 11 - GEOS 1004, SPOTILA Lecture 11, 10/6/09 EARLY...

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GEOS 1004, SPOTILA Lecture 11, 10/6/09 EARLY EARTH HISTORY Early history = there were major changes in Earth interior, surface, and biosphere. The early evolution of the planet was in our favor. ..What is the "miracle" of earth? The goldilocks effect Just enough gravity Right distance from the sun Protection by magnetic field Ozone (protects from UV radiation) After the earth forms, it is initially molten, but cools and differentiates into core and mantle within 100 million years or so. The early history of the solid earth is called "Hadean earth". What was it like? -Lots of volcanism, lots of meteorite impacts, really hot II) Surface 1) Oceans Where did the water come from? -it was already in the earth (given off as gas during volcansim) *given off as gas during volcanism + CO2, N2 (create atmosphere) + H2 - escapes to space How do we know? What is the first record of liquid water on the surface of the earth, and how old is it? First sedimentary rocks (4.0 billion years ago)
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This note was uploaded on 09/11/2011 for the course GEOG 1004 at Virginia Tech.

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Lecture 11 - GEOS 1004, SPOTILA Lecture 11, 10/6/09 EARLY...

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