ESC 1000 Chapter 8: Chapter Eight Notes
8 Apr 2016
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Document Summary
Regional variaions in elevaion primarily relect the tectonic processes that occurred in the region, and the nature of the crust and mantle at depth. Regional variaions are controlled primarily by the thickness of the crust, but they can also be inluenced by the temperature and density of materials in the crust and upper mantle. Regions with thick crust are higher than those with thinned crust. Regions underlain by less dense materials in the crust will be higher in elevaion than areas with a similar thickness of more dense crust. Warm rock are less dense and in higher areas than cold, denser rocks. Diferences in crustal thickness between regions relect diferences in their geologic histories. Coninents have thicker crusts (30-50 km) and are higher than ocean basins underlain by oceanic crusts (7 km) Crust can thicken and thin if compressed and stretched, respecively. Rock can contract when cool, so large regions may subside.
