Darfur Dome or Darfur Volcanic Province is an area about 100x400 km in area in Western Sudan, the result of a volcanic plume which created its best-known and central feature, Deriba Crater. It also produced the surrounding Marra Mountains (Jebel Marra) and Tagabo Hills, formed around 16 and 10 Ma., and the Meidob Hills which arose around 6.8 Ma. The plume is linked to stress resolution along the Central African Fault Zone.
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 terminates to the north on the faulted Mesozoic deposits south of the Darfur Dome.
The Babanusa trough has extensive faulting, increasing towards the south, reaching a depth of 5 km at the Unity oil field and 11 km south of the Bentiu oil fields.Deriba (caldera)
Deriba is a Pleistocene or Holocene caldera in Darfur, Sudan. Part of the volcanoes of the Marra Mountains, it lies on the Darfur dome and like the Tagabo Hills and Meidob Hills volcanism may be the consequence of a mantle plume. The highest point of Sudan (after the separation of South Sudan) lies on the margin of the caldera.
The caldera lies atop a shield volcano or ash cone in the southern Marra Mountains, which developed first as a pile of basaltic lava flows and later as layers of volcanic ash and tuff, including the eruptions that formed the caldera. A large eruption occurred about 3,520 ± 100 years before present, and hot springs and fumaroles are active to the present day.
Deriba contains two lakes, one in the northeastern side of the main caldera and the other in a cone in the southwestern sector of the Deriba caldera. The fresher southwestern lake is smaller but considerably deeper than the saltier northeastern lake; in the late Pleistocene the caldera was filled with a larger lake.Meidob volcanic field
Meidob volcanic field is a Holocene volcanic field in Darfur, Sudan. It is one of several volcanic fields in Africa whose origin is explained with the activity of mantle plumes and their interaction with crustal structures. Meidob lies at the southern margin of the Sahara.
The volcanic field is formed by overlapping lava flows, which cover an area of 100 by 50 kilometres (62 mi × 31 mi) and emanate from about 700 vents, mainly scoria cones. Lava domes, fallout and pyroclastic flow deposits are also common. Among the vents is the Malha crater, which presently contains a small lake. The volcanic field has erupted rocks ranging from basanite to trachyte and rises from a tectonic uplift known as the Darfur dome.
Volcanic activity in Meidob began 6.8 million years ago and continued into the Holocene, with the most recent eruptions dated to 4,900 ± 520 years ago. There are no geothermal manifestations at Meidob, but legends of the local people imply that they witnessed volcanic eruptions in the field.