Structural Geomorphology

Structural Geomorphology - Structural: 1 Structural &...

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Structural & Volcanic Geomorphology Structural Geomorphology Crustal Deformation Differential Weathering & Erosion Drainage Patterns Structural Geomorphology Crustal Deformation Forces acting on the earth's crust can move the crust around- pushing it up, dropping it down, compressing it or pulling it apart. Plate tectonics accounts for much of this, although isostatic rebound is an example of another. Rocks react in different ways to the application of stress from these forces. If the force is small, then the rock may react in an elastic fashion. This is where the rock is compressed, but if the stress is removed, the rock will return to its original shape. Moderate stress leads to plastic deformation , where the rock slowly flows to a new shape. Even if the stress stops, the rock will maintain its new shape. The application of a strong stress often leads to rupture , where the rock breaks. The amount of stress required to achieve each of these depends on the type of rock (how brittle is it?). Let's start by looking at the consequences of regional uplift and subsidence. If a region is uplifted and the force is equal over the entire area, then a plateau results. This is an extensive, flat area raised up above its surroundings. The Colorado Plateau is a good example, covering much of Southern Utah, Northern Arizona, Southwestern Colorado and Northwestern Mew Mexico. Streams have cut into the Plateau, leaving such features as the Grand Canyon. If the uplifting force is concentrated at one place, then a dome may result. Here the center of the area is raised up and the surrounding land is deformed plastically to create a dome shape. The Black Hills of South Dakota were initially created this way. Domes are sometimes caused by upwelling magma pushing up on the surface. The opposite of a dome is a basin , which is created when an area sinks. This is another
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Structural Geomorphology - Structural: 1 Structural &...

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