GEOG 1403H Study Guide - Continental Crust, Continental Drift, Humus
Document Summary
In a previous lecture we learned that the earth is differentiated into various layers: There is a solid iron core, surrounded by liquid iron. There is a large mantle under enormous pressure and encased in a hot asthenosphere layer, which in turn is encased in a cool and brittle lithosphere. Atop the lithosphere are the continental and oceanic crusts that form the surface of our planet. The crusts are dynamic, changing over time: not only by continental drift, as we discussed, but also accumulating sediment that runs against the continental crust or subducted underneath. The continental crust can be built up by converging lithospheric plates, producing mountains, and cooling magma from volcanoes, can be broken down by wind and water erosion. Along the very top layer of the continental crust we can find soil. Soil is comprised of disintegrated rock and humus. As we can see, it is itself differentiated into layers.
