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Blue Nile Basin
The Blue Nile Basin is a major geological formation in the northwestern Ethiopian Plateau formed in the Mesozoic Era during a period of crustal extension associated with the break-up of Gondwana, and filled with sedimentary deposits. The modern Blue Nile river cuts across part of the sedimentary basin. Strata The Blue Nile basin originated in an area of Neoproterozoic rocks aged about 750 Ma that had become a peneplain, possibly during the Paleozoic era (540–250 MaMa = Million years ago). The basin was formed due to rifting during the Mesozoic era (250–66 Ma). Between the Triassic and early Jurassic, about 300 m of fluvial sediments were deposited by rivers and streams. During the Jurassic (200–145 Ma) the basin was twice covered by an arm of the Indian Ocean for extended periods, creating a lower limestone sediment 450 m thick and an upper limestone sediment 400 m thick. In the late Jurassic and early Cretaceous periods the basin rose, and the 280 m upp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central African Rifts
Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as Middle Africa * Central America, a region in the centre of America continent * Central Asia, a region in the centre of Eurasian continent * Central Australia, a region of the Australian continent * Central Belt, an area in the centre of Scotland * Central Europe, a region of the European continent * Central London, the centre of London * Central Region (other) * Central United States, a region of the United States of America Specific locations Countries * Central African Republic, a country in Africa States and provinces * Blue Nile (state) or Central, a state in Sudan * Central Department, Paraguay * Central Province (Kenya) * Central Province (Papua New Guinea) * Central Province (Solomon Islands) * Central Province, Sri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" ... Epoch. The Oligocene is the third and final epoch of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anza Trough
The Anza trough is a rift in Kenya that was formed in the Jurassic Period of the Mesozoic Era. The trough runs inland from the coast in the northwest direction. The trough is an isolated graben originating from the uprising mantle-plume rift forming processes. It is not connected to the East Kenya Jurassic triple junction but temporally associated with the CARS formed during the initial stretching phase when Gondwana was breaking up. The rift was formed by the same forces that created the rift system in South Sudan, and connects those rifts to the Lamu embayment further to the south. The separation of the other two arms of the junction allowed India-Madagascar to separate from Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area .... The trough is now hidden by a cover of Quatern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shear Zone
In geology, a shear zone is a thin zone within the Earth's crust or upper mantle that has been strongly deformed, due to the walls of rock on either side of the zone slipping past each other. In the upper crust, where rock is brittle, the shear zone takes the form of a fracture called a fault. In the lower crust and mantle, the extreme conditions of pressure and temperature make the rock ductile. That is, the rock is capable of slowly deforming without fracture, like hot metal being worked by a blacksmith. Here the shear zone is a wider zone, in which the ductile rock has slowly flowed to accommodate the relative motion of the rock walls on either side. Because shear zones are found across a wide depth-range, a great variety of different rock types with their characteristic structures are associated with shear zones. General introduction A shear zone is a zone of strong deformation (with a high strain rate) surrounded by rocks with a lower state of finite strain. It i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 how the individual shears along the lineament link up. Description The shear zone dates to at least 640 Ma (million years ago). Motion occurred along the zone during the break-up of Gondwanaland in the Jurassic and Cretaceous periods. Some of the faults in the zone were rejuvenated more than once before and during the opening of the South Atlantic in the Cretaceous period. It has been proposed that the Pernambuco fault in Brazil is a continuation of the shear zone to the west. In Cameroon, the CASZ cuts across the Adamawa uplift, a post-Cretaeous formation. The Benue Trough lies to the north, and the Foumban Shear Zone to the south. Volcanic activity has occurred along most of the length of the Cameroon line from 130 Ma to the present, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muglad Basin
The Muglad Basin is a large rift basin in Northern Africa. The basin is situated within southern Sudan and South Sudan, and it covers an area of approximately across the two nations. It contains a number of hydrocarbon accumulations of various sizes, the largest of which are the Heglig and Unity oil fields. During the 1960s and 1970s, Chevron made the first oil discoveries in the basin near the towns of Bentiu, Malakal, and Muglad. Taken together, the Muglad and Melut rift basins account for the majority of Sudan's known oil reserves. The oil fields of the Muglad Basin are connected to Port Sudan on the Red Sea by the Greater Nile Oil Pipeline which begins at the Unity oil field. Oil extracted in Muglad is known as "Nile Blend" crude. It is refined at Khartoum for export and domestic consumption. Further oil exploration Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melut Basin
The Melut Basin is a rift basin in South Sudan, extending into Ethiopia, where it is called the Gambella basin. Melut is situated in the Upper Nile and Jonglei, south of the capital of Sudan, Khartoum and east of the river Nile. Some parts of the Melut contain several known hydrocarbon accumulations, although oil exploration, as elsewhere in Sudan and South Sudan, has been hindered by instability and conflict. The largest oil field in the Basin is the Great Palogue Field in South Sudan, with estimated reserves of 900 million barrels. The Melut oil export pipeline travels 1,380 km from Palogue to Port Sudan on the Red Sea, and has been on stream since June 2006. The export pipeline is also known as the PetroDar The PetroDar Operating Company Ltd is a consortium of oil exploration and production companies operating in Sudan with its headquarters in Khartoum. The consortium was incorporated in the Virgin Islands on 31 October 2001. PetroDar is composed of ... Pipeline after t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 area such as the Bahr El Arab rift and White Nile rift, appears to have been activated several times since the Paleozoic 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 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 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 Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Ethiopian Rift
Main may refer to: Geography *Main River (other) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries *'' The Main'', the diverse core running through Montreal, Quebec, Canada, also separating the Two Solitudes *Main (lunar crater), located near the north pole of the Moon * Main (Martian crater) People and organisations *Main (surname), a list of people with this family name *Ma'in, alternate spelling for the Minaeans, an ancient people of modern-day Yemen * Main (band), a British ambient band formed in 1991 *Chas. T. Main, an American engineering and hydroelectric company founded in 1893 *MAIN (Mountain Area Information Network), former operator of WPVM-LP (MAIN-FM) in Asheville, North Carolina, U.S. Ships * ''Main'' (ship), an iron sailing ship launched in 1884 * SS ''Main'', list of steamships with this name * ''Main'' (A515), a mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clastic
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks by physical weathering.Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-5 Geologists use the term clastic to refer to sedimentary rocks and particles in sediment transport, whether in suspension or as bed load, and in sediment deposits. Sedimentary clastic rocks Clastic sedimentary rocks are rocks composed predominantly of broken pieces or ''clasts'' of older weathered and eroded rocks. Clastic sediments or sedimentary rocks are classified based on grain size, clast and cementing material (matrix) composition, and texture. The classification factors are often useful in determining a sample's environment of deposition. An example of clastic environment would be a river system in which the full range of grains being transpor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago (Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic Period is subdivided into three epochs: Early Triassic, Middle Triassic and Late Triassic. The Triassic began in the wake of the Permian–Triassic extinction event, which left the Earth's biosphere impoverished; it was well into the middle of the Triassic before life recovered its former diversity. Three categories of organisms can be distinguished in the Triassic record: survivors from the extinction event, new groups that flourished briefly, and other new groups that went on to dominate the Mesozoic Era. Reptiles, especially archosaurs, were the chief terrestrial vertebrates during this time. A specialized subgroup of arch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
