Earth Sciences 2240F/G Lecture Notes - Lecture 9: Mantle Plume, Large Low-Shear-Velocity Provinces, Continental Crust
20 Jan 2018
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Document Summary
2. 0 large igneous provinces: defined on oceanic crust, continental crust or a mix of both, voluminous emplacements of mainly basaltic extrusive (and intrusive) rock whose origins lie in processes other than. "normal" seafloor spreading: plate tectonics can not explain large igneous provinces, they differ in their trace element content and mix of atomic isotopes. 3. 0 mantle plumes, rifting and floods of basalt: on continents, the expression of lava eruption from plumes appears as broad, flat surfaces, "plateaus", although not particularly elevated. 4. 0 laki, iceland: 1783-84, about 14. 7 km3 of basalt poured out of fissures, 80-100 million tonnes of sulfuric acid aerosols were created by laki and put into the atmosphere lowered global temp 1 degree for a year. In the thickest flows, reversals are found, and interpretation of them suggests that the major pulse of volcanism could have lasted for a maximum of 600,000 years. These zones are hot spot or plume locations.
