The Blue Nile rift is a major geological formation in the Sudan, a

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 ...

with a NW trend that terminates on 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 ...

. It was formed through crustal extension during the break-up of Gondwana. The rift, and other rifts in the area such as the

Bahr El Arab rift The Bahr el Arab rift is a major geological feature in the southwest Sudan. The Bahr el Arab rift is made up of the Baggara graben, between the Central African Republic and the Nuba Mountains to the east, and the Sudd graben further south. It t ...

and White Nile rift, appears to have been activated several times since the

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

era, which ended about 250 Ma.Ma = Million years ago During periods of rapid uplift and subsidence, the rifts accumulated sediments of different ages, origins and methods of deposition. Late

Jurassic The Jurassic ( ) is a geologic period and stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of ...

rifting occurred in the Blue Nile rift, with east-west half-graben extension connected by large-scale shear zones and pull-apart basins, and early

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 ...

rifting re-activated the Jurassic basin. The Blue Nile Basin in

Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...

may be a southeastern extension of the rift. Further to the southeast, the late Palaeozoic-Mesozoic Ogaden Rift is aligned with the Blue Nile rift.

Explanatory notes

References

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