Earth Sciences 1022A/B Lecture 13: Lecture 13 - Mountain Building and Continental Frameworks

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 1022A/B
• Professor: Stephen R Hicock

Document Summary

Mountain building and continental frameworks y continents rise above oceans due to isostasy y divergent y passive y convergent: different types: andean: oceanic crust subducts beneath continental. creates an accretionary wedge, continental volcanic arc, and plutons i the core of deformed mountain belt: aleutian: oceanic-oceanic volcanic island arc. Japan: continental collision: ocean closes subduction stops, high mountains. Himalayas: accreted terranes: foreign crustal fragments stuck onto margin. Canadian shield y broad vertical movements: uplift mantle upwelling pushes up lithosphere in continental interiors. Southwestern usa (nevada, idaho: subsidence sediment load along passive margins, or downward flow in the mantle under continental lithosphere. Alberta y origin and evolution of continents: original continental crust probably formed by coalescing volcanic arcs above subduction zones, today the earliest continental crust is found in shield areas of continental interiors.