Earth Sciences 1022A/B Lecture Notes - Lecture 13: Obduction, Subduction, Subsidence
7 Dec 2015
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Earth sciences 1022a lecture 13 mountain building and continental frameworks. Masses of continental crust will sit on top of mantle, and they adjust with their weight. Mountain (orogenic) belts parallel plate boundaries in three main settings of continental margins volcanoes along sides. Divergent: continental lithosphere uplifted, splits over mantle plume rift valley, Rarely pieces of oceanic crust got stuck onto continental margin during obduction o. Obduction: stuff gets scraped off the sea floor, and rises up as mountains build. Uplift: mantle upwelling pushing up continental lithosphere in continent interiors o. E. g. the southwestern united states in from the pacific ocean o o o. A mantle plume develops under a continent and causes the continent to split. A rift starts to form mountain belts on either side, mountain ranges and volcanos develop there. As continental divergence continues, we get an oceanic ridge, sea water invades, and we have a new ocean basin.
