17.1 Notes: Earth’s Mantle & Crust
Continental crustThickness: Continental crust is thicker (30-40Km)
Age: older (up to 4.4 billion yrs old)
Composition: Granite, w/ basalt & diorite beneath
Density: Less dense
Oceanic Crust
Thickness: Thinner (6-11km)
Age: younger (200 million yrs old)
Composition: basalt gabbro
Density: more dense
Moho (Mohorovičić discontinuity) Structure: a low pressure & temperature region, so rock becomes more rigid & slows down seismic waves.
Upper Mantle
Structure: Thin top section w/ extreme pressures. Pressures & temperature increase with depth.
Describe movement between lower & upper mantle:Rock isn’t quite solid here so it moves like a very thick liquid (due to convection).
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