Aleutian Arc - Tectonic Magmatic Setting
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Title
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Aleutian Arc - Tectonic Magmatic Setting
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Description
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A convergent margin is formed when two lithospheric plates collide. The Aleutian Arc formed as the result of the Pacific plate colliding with the North American plate. The Pacific plate is subducting under the North American plate because it is denser (Fig. 1). The subducting plate is essential for even creating melts at the margin. The Pacific plate is moving NW at a rate of between 7 and 11 centimeters per year, whereas the North American plate is moving SW at only 1 centimeter a year. Magma is generated between the subducting slab and the overriding one in the mantle wedge. From there melt rises through the overriding plate creating an island arc chain such as the Aleutian Arc. As the magma rises it may assimilate surrounding rock, stall depending on how mature the overlying arc is physiographically, and evolve through the process of fractionation.
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Subject
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An explanation of the tectonic magmatic setting that exists at the Aleutian Arc convergent margin.
