EESA06H3 Chapter Notes - Chapter 4: Epicenter, Outer Core, Ultramafic Rock
Document Summary
Highly variable/complex , consisting of a crystalline basement composed of granite, other plutonic rocks, gneisses, and schists, all capped by a layer of sedimentary rocks like icing on a cake: some geoscientists use the term. Felsic rocks high in feldspar and silicon for continental crust. Mafic rocks high in magnesium and iron (ferric) for oceanic crust: continental crust thickest under geologically young mountain ranges such as the andes & Himalayas bulging downward as a mountain root into the mantle: continental crust also less dense than oceanic crust (important in plate tectonics, the boundary that separates the crust from the mantle beneath it is called the mohorovicic. Discontinuity ( moho : mantle lies closer to earth"s surface beneath the ocean than it does beneath the continents, project mohole. To use specially equipped ships to drill through oceanic crust and obtain samples from the mantle. Abandoned due to high costs; but ocean floor drilling has become a routine since.
