Continental Lithosphere And Its Effect On The Earth 's Continental Crust

1330 Words May 6th, 2015 6 Pages
Earth 's continental crust is always in motion. The process through which the lithosphere is stretched and thinned is called rifting and the area of faulting that results from a horizontal tension caused by spreading beneath the continent is a rift. The Earth 's continental crust is stretched to a point where it becomes thinner in some parts, which are known as continental rift zones. As this happens, the asthenosphere rises upwards and bursts through the thin crust as magma. The forces of mantle convection causes this mantle to shift and push against the crust. As a result, processes such as continental rifting occur. With the continued expansion of a rift zone, a continent can keep spreading to the point where it is split in two, thus creating an ocean basin between the two sides and ridge system between. The proposed mechanisms for continental rifting can be boiled down to two things: hot mobile rock plumes and forces from plate motion. Continental rifting signifies the beginning of continental separation where extension can lead to lithospheric rupture and result in the creation of a new ocean basin. If the rifting process reaches the rupture point, the continental rift will become inactive sooner or later and result in either a passive or rifted continental margin. It should be noted however that not all rifts result in the formation of new ocean crust. Failed rifts, also known as aulacogens, become inactive during some stage of their evolution. Some types of failed…
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