Rift basinLithospheric plateIt is developed in the crust during the back horizontal movement or mantle uplift, and shows symmetric or asymmetric central depression in geomorphologyvalley。According to its location, it can be divided into continental rift, continental margin rift, intercontinental rift and oceanic rift.
Rift basinGeodynamicsThe mechanism can generally be summed up as three main tectonic stresses: crustal tension, compression and shear.In fact, the formation of many rift basins is related to the complex tectonic transformation and basin forming process.Crustal extension theory: rift is the result of active upwelling of the mantle asthenosphere, forming the upper mantle uplift, causing the thermal expansion of the crust, and generating tensile fault depression.Crustal compression theory: the crust is compressed, resulting in surface uplift and crustal thickening;The compressive stress relaxes or stops, and the density difference between the lithosphere and asthenosphere makes gravity unstable, resulting in mantle delamination and lithosphere thinning, thus causing the crustal extension and collapse to become a rift.Crustal strike slip pull apart theory: the crust is subject to uneven compression, and large strike slip fault zones often occur along its weak parts. The multi cycle intense shear activity along the strike slip fault zones is bound to form pull apart fault depressions at the ends of the strike slip faults, and cause the upper mantle materials and the soft flow layer materials of the middle and lower crust to flow upward along the fault zones, resulting in riftsbasin。
