GEOL 212 Study Guide - Quiz Guide: Ductility, Continental Crust, Bulk Density
26 Dec 2017
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Document Summary
It"s recognition is one of the great breakthroughs in geology, so we approach it historically in this presentation. The first practical exploration of the ocean basins occurred in 1872: when the british government sponsored the first interdisciplinary research expedition to expore the world"s oceans. The four-year voyage of the h. m. s. challenger. President jackson seamount chain: the ocean basins were mostly flat. Such hills as existed were isolated cones, i. e. volcanoes: sediments, when present, were very thin. Fresh basalt outcrop: all of the bedrock was basalt or its derivatives, a rock that forms from the cooling of erupting magma. This was true even when there were no nearby volcanoes. Peridotite - characteristic rock of earth"s mantle: basalt is a relatively dense mg and fe rich rock. Because of this, the bulk density of ocean floor was distinctly greater than that of continental crust.
