habitable planet

Subdecks (2)

on what basis (property is the oceanic crust distringuished from the continental crust? what is the average thickness of each?
oceanic crust is thinner with an average of 7-10km thick, more dense, made up of basalt and gabbro with a layer of clay and shells. continental crust is thicker with an average of 35-45km thick, less dense, and has much more rock type variation
what is the source of earth's internal energy?
heat in earth's core from formation and radioiactive decay
what are some processes driven by earth's internal energy?
plate movements, mountain building, earthquakes, volcanoes
what is the age of the rocks and how is it determined?
4.56 billion years old according to radiometric dating of rock layers
why is the oldest oceanic lithosphere less than 200Ma?
seafloor spreading from mid ocean ridges forms ew oceanic crust and the old crust subducts
why is some continental crust older than 4Ga? 
continental crust is too buoyant to subduct so it does not get recycled
describe a passive continental margin. what are some present day examples?
a continental margin without a corresponding plate boundary, inheritantly without much seismicity. some examples are the gulf coast of the united states, atlantic coasts of brazil and africa
why do thick deposits of sediment accumulate on passive continental margins?
ocean currents, sea level change, erosion, transport sediment to the continental shelf and because of their techtonic stability, this accumulation is undisrupted