Search results
Results from the WOW.Com Content Network
Subsidence frequently causes major problems in karst terrains, where dissolution of limestone by fluid flow in the subsurface creates voids (i.e., caves).If the roof of a void becomes too weak, it can collapse and the overlying rock and earth will fall into the space, causing subsidence at the surface.
The broad central parts of continents are called cratons, and are subject to epeirogeny. [2] The movement may be one of subsidence toward, or of uplift from, the center of Earth. The movement is caused by a set of forces acting along an Earth radius, such as those contributing to isostasy and faulting in the lithosphere.
A slope which falls down to a deep valley on its western side and a shallower one on its eastern side has a westerly aspect or is a west-facing slope. The direction a slope faces can affect the physical and biotic features of the slope, known as a slope effect.
Panhole: a shallow depression or basin eroded into flat or gently sloping, cohesive rock. [2] Collapse-related: Sinkhole: a depression formed as a result of the collapse of rocks lying above a hollow. This is common in karst regions. Kettle: a shallow, sediment-filled body of water formed by melting glacial remnants in terminal moraines. [3]
The shelf usually ends at a point of increasing slope [3] (called the shelf break). The sea floor below the break is the continental slope. [4] Below the slope is the continental rise, which finally merges into the deep ocean floor, the abyssal plain. [5] The continental shelf and the slope are part of the continental margin. [6]
Tectonic subsidence is the sinking of the Earth's crust on a large scale, relative to crustal-scale features or the geoid. [1] The movement of crustal plates and accommodation spaces produced by faulting [2] brought about subsidence on a large scale in a variety of environments, including passive margins, aulacogens, fore-arc basins, foreland basins, intercontinental basins and pull-apart basins.
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
Sediments and some trapped water are carried downwards by the slab and recycled into the deep mantle. [11] So far, Earth is the only planet where subduction is known to occur, and subduction zones are its most important tectonic feature. Subduction is the driving force behind plate tectonics, and without it, plate tectonics could not occur. [12]