Editing Sedimentary basin (section)

=== Lithospheric stretching ===
[[File:Formation of passive margins cropped.svg|thumb|right|Illustration of lithospheric stretching]]
If the [[lithosphere]] is caused to stretch horizontally, by mechanisms such as rifting (which is associated with divergent plate boundaries) or ''ridge-push'' or ''trench-pull'' (associated with convergent boundaries), the effect is believed to be twofold. The lower, hotter part of the lithosphere will "flow" slowly away from the main area being stretched, whilst the upper, cooler and more brittle [[Crust (geology)|crust]] will tend to fault (crack) and fracture. The combined effect of these two mechanisms is for Earth's surface in the area of extension to subside, creating a geographical depression which is then often infilled with water and/or sediments. (An analogy is a piece of rubber, which thins in the middle when stretched.)

An example of a basin caused by lithospheric stretching is the [[North Sea]] – also an important location for significant [[hydrocarbon]] reserves. Another such feature is the [[Basin and Range Province]] which covers most of Nevada, forming a series of [[Horst (geology)|horst]] and [[graben]] structures.

Tectonic extension at divergent boundaries where continental rifting is occurring can create a nascent ocean basin leading to either an ocean or the [[aulacogen|failure of the rift zone]]. Another expression of lithospheric stretching results in the formation of ocean basins with central ridges. The [[Red Sea]] is in fact an incipient ocean, in a plate tectonic context. The mouth of the Red Sea is also a tectonic [[triple junction]] where the Indian Ocean Ridge, Red Sea Rift and [[East African Rift]] meet. This is the only place on the planet where such a triple junction in oceanic crust is exposed [[subaerial]]ly. This is due to a high thermal buoyancy ([[thermal subsidence]]) of the junction, and also to a local crumpled zone of seafloor crust acting as a dam against the Red Sea.