Study Guide #10

Study Guide #10 - Study Questions GEOL 125: Earth History...

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Study Questions Guide #10 (F07) GEOL 125: Earth History Dr. Hammond Draw a graph illustrating the rate of bolide (comets and meteors) impacts through time, from 4.5 by to the present. How was this information determined? Bolide Graph=graph of lunar crater history (can be found in ch. 17 on page 2: FIG 17-1 ) This information is determined when a bolide (comet or asteroid) falls from space and hits the Earth and explodes. It creates an impact crater. The rate of cratering through time is determined by the crater density on different parts of the moon’s surface.\ Why did the crust separate from the mantle? What differences exist between the oceanic and continental crust in composition and density? The crust separated from the mantle because the lithosphere was very thin and dense. This caused the cool crust to brake up and sink into the hot, low density upper mantle. Oceanic Crust vs. Continental Crust o Oceanic Crust: basaltic; higher density (3.0 g/cm) o Continental Crust: granitic; lower density (2.7 g/cm) o Mantle: 3.3 g/cm o Granites (continental) have a lower density than basalt (oceanic) and continents appear to be a low density scum that has extracted from the mantle has evolved Draw a graph illustrating the number of genera vs. geologic time, noting any distinct changes. What is a mass extinction? What mechanisms might cause mass extinctions? What happened at the Cretaceous-Tertiary (K-T) Boundary and what is the evidence? See graph in Ch. 14, pg. 6:
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This note was uploaded on 02/27/2008 for the course GEOL 125Lxg taught by Professor Hammond during the Fall '07 term at USC.

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Study Guide #10 - Study Questions GEOL 125: Earth History...

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