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Eburnean Orogeny
The Eburnean orogeny, or Eburnean cycle, was a series of tectonic, metamorphic and plutonic events in what is now West Africa during the Paleoproterozoic era about 2200–2000 million years ago. During this period the Birimian domain in West Africa was established and structured. Eburnian faults are found in the Eglab shield to the north of the West African craton and in the Man Shield to the south of the craton. There is evidence of three major Eburnean magmatic events in the Eglab shield. Between 2210 and 2180 Ma, a metamorphosed batholith was formed in the Lower Reguibat Complex (LRC). Around 2090 Ma, a syntectonic trondhjemitic pluton intruded into the Archaean reelects of the Chegga series. Around 2070 Ma an asthenospheric upwelling released a large volume of post-orogenic magmas. Eburnian trends within the Eglab shield were repeatedly reactivated from the Neoproterozoic to the Mesozoic. See also *Geology of Ghana The geology of Ghana is primarily very ancient cryst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
USGS Geologic Map Ghana
The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The organization's work spans the disciplines of biology, geography, geology, and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility. The agency was founded on March 3, 1879. The USGS is a bureau of the United States Department of the Interior; it is that department's sole scientific agency. The USGS employs approximately 8,670 people and is headquartered in Reston, Virginia. The USGS also has major offices near Lakewood, Colorado, at the Denver Federal Center, and Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on the occasion of its hundredth anniv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Man Shield
The Man Shield (Leo-Man Shield or Leo-Man Craton) is a geological shield or craton in the southeast portion of the West African Craton. The shield is in part overlaid by gold-bearing Birimian formations. Geography and Geology The shield covers the countries Ivory Coast, Mali, Burkina Faso, Ghana, Sierra Leone, Liberia, and Guinea.Jessell M.W., Liégeois J-P. (2015). "100 years of research on the West African Craton". ''Journal of African Earth Sciences''. 112(B): 377– 381. this shield, a large portion of the WAC consists of Paleoproterozoic Birimian continent margins.Ennih N. & Liégeois J-P. (2008). ''The Boundaries of the West African Craton''. Geological Society, London, Special Publications. 297: 1–17. The Birimian units were initially produced in an immature volcanic arc setting, which was later metamorphosed during the Eburnean orogeny. The poor exposure of the greenstone belt in the area limits interpretations of a broad structural c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Mali
Mali is a landlocked nation in West Africa, located southwest of Algeria, extending south-west from the southern Sahara Desert through the Sahel to the Sudanian savanna zone. Mali's size is 1,240,192 square kilometers. Desert or semi-desert covers about 65 percent of Mali's total area (1,240,192 square kilometers). The Niger River creates a large and fertile inland delta as it arcs northeast through Mali from Guinea before turning south and eventually emptying into the Gulf of Guinea. The territory encompasses three natural zones: the southern cultivated Sudanese zone, central semi-desert Sahelian zone, and northern desert Saharan zone. The terrain is primarily savanna in the south and flat to rolling plains or high plateau (200–500 meters in elevation) in the north. There are rugged hills in the northeast, with elevations of up to 1,000 meters. The Niger (with 1,693 kilometers in Mali) and Senegal are Mali's two largest rivers. The Niger is generally described as Mali's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Ivory Coast
The geology of Ivory Coast is almost entirely extremely ancient metamorphic and igneous crystalline basement rock between 2.1 and more than 3.5 billion years old, comprising part of the stable continental crust of the West African Craton. Near the surface, these ancient rocks have weathered into sediments and soils 20 to 45 meters thick on average, which holds much of Ivory Coast's groundwater. More recent sedimentary rocks are found along the coast. The country has extensive mineral resources such as gold, diamonds, nickel and bauxite as well as offshore oil and gas. Stratigraphy, Tectonics & Geologic History Virtually all of Ivory Coast is underlain by very ancient rocks from the Archean and the Paleoproterozoic that form part of the West African Craton, except for Cenozoic sediments and sedimentary rocks along the coast and in offshore basins. Weathering has rendered the upper layers of ancient Precambrian crystalline basement rock into sediments and soils. Archean Three bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
