The White Nile rift is one of several

rift In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-grabe ...

s in central Sudan running in a NW direction and terminating in the

Central African Shear Zone The Central African Shear Zone (CASZ) (or Shear System) is a wrench fault system extending in an ENE direction from the Gulf of Guinea through Cameroon into Sudan. The structure is not well understood. , there was still no general agreement about ...

. The rift is a

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

structure that has similar tectonic characteristics to the Southern Sudan Rift,

Blue Nile rift The Blue Nile rift is a major geological formation in the Sudan, a rift with a NW trend that terminates on the Central African Shear Zone. It was formed through crustal extension during the break-up of Gondwana. The rift, and other rifts in the ...

and Atbara rift. These rifts follow similar trends, and terminate in a line at their northwestern ends. Probably this line is an extension of the Central African Shear Zone through the Sudan. The rift basin is formed by the junction of the Umm Rubaba grabens, which extends in a NW direction, and the White Nile graben, which extends in a N to NW direction. The basin is filled with sediments and igneous rocks, and is a target for oil and gas exploration. The rift basins appear to be hydrologically closed, with no lateral transfer of water. One theory is that the current White Nile may have developed no more than 12,500 years ago when the basins filled and the rivers became connected.

References

Geology of Africa Mesozoic rifts and grabens Mesozoic Africa {{tectonics-stub