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Lake Chad
Lake Chad (, Kanuri language, Kanuri: ''Sádǝ'', ) is an endorheic freshwater lake located at the junction of four countries: Nigeria, Niger, Chad, and Cameroon, in western and central Africa respectively, with a catchment area in excess of . It is an important wetland ecosystem in West-Central Africa. The lakeside is rich in reeds and swamps, and the plain along the lake is fertile, making it an important irrigated agricultural area. The lake is rich in aquatic resources and is one of the important freshwater fish producing areas in Africa. Lake Chad is divided into deeper southern parts and shallower northern parts. The water source of the lake mainly comes from rivers such as the Chari River that enter the lake. The water level varies greatly seasonally, and the area of the lake also changes dramatically. During the African humid period, the lake's area reached . Due to the increasingly arid climate, the lake surface gradually shrank. In the 19th century, it still had an are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sahel
The Sahel region (; ), or Sahelian acacia savanna, is a Biogeography, biogeographical region in Africa. It is the Ecotone, transition zone between the more humid Sudanian savannas to its south and the drier Sahara to the north. The Sahel has a Semi-arid climate#Hot semi-arid climates, hot semi-arid climate and stretches across the tropics, southernmost latitudes of North Africa between the Atlantic Ocean and the Red Sea. Although geographically located in the tropics, the Sahel does not have a tropical climate. Especially in the western Sahel, there are droughts in the Sahel, frequent shortages of food and water due to its very high Corruption Perceptions Index, government corruption and the semi-arid climate. This is exacerbated by very high list of countries by birth rate, birthrates across the region, resulting in a rapid increase in population. In recent times, various Coup Belt, coups, Foreign internal defense#Preemptive counterinsurgency in Africa, insurgencies, terrorism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kanuri Language
Kanuri () is a Saharan dialect continuum of the Nilo–Saharan language family spoken by the Kanuri and Kanembu peoples in Nigeria, Niger, Chad and Cameroon, as well as by a diaspora community residing in Sudan. Background At the turn of the 21st century, its two main dialects, Manga Kanuri and Yerwa Kanuri (also called Beriberi, which its speakers consider to be pejorative), were spoken by 9,700,000 people in Central Africa. It belongs to the Western Saharan subphylum of Nilo-Saharan. Kanuri is the language associated with the Kanem and Bornu empires that dominated the Lake Chad region for a thousand years. The basic word order of Kanuri sentences is subject–object–verb. It is typologically unusual in simultaneously having postpositions and post-nominal modifiers – for example, 'Bintu's pot' would be expressed as , 'pot Bintu-of'. Kanuri has three tones: high, low, and falling. It has an extensive system of consonantal lenition; for example, 'they' + 'have eaten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mayo Kébbi
The Mayo Kébbi is a river in Central and West Africa. The river rises in Chad, then flows west into the Bénoué River. Mayo-Kébbi Prefecture in Chad is named for it. The Mayo Kébbi is the major outlet for Lake Fianga, shared between Cameroon and Chad. In the past, the Mayo Kébbi served as the outlet of the paleolake Mega-Chad. The presence of African manatees in the inflows of Lake Chad is evidence of this, since the manatee is otherwise only in rivers connected to the Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ... (i.e. it is not possible that it evolved separately in an enclosed Chad Basin). The grand scale of the Mayo Kébbi river course is also evidence of earlier overflow from Mega-Chad; the upstream catchment of today is far too small to have dug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benue River
Benue River (), previously known as the Chadda River or Tchadda, is a major tributary of the Niger River. The size of its catchment basin is 319,000 km2 (123,000 sq mi). Almost its entire length of Approximation, approximately is navigable during the summer months. As a result, it is an important transportation route in the regions through which it flows. The name ''Benue State, Benue'' comes from ''Binuwe,'' meaning 'Mother of Waters’ in the Bata language, Batta language. Geography The Benue rises in the Adamawa Plateau of northern Cameroon, from where it flows west, and through the town of Garoua and Lagdo Reservoir, into Nigeria south of the Mandara mountains, and through Jimeta, Ibi, Nigeria, Ibi and Makurdi before meeting the Niger River at Lokoja. Large tributaries are the Faro River, the Gongola River and the Mayo Kébbi, which connects it with the Logone River (part of the Lake Chad system) during floods. Other tributaries include Taraba River and River Katsina Ala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacustrine Deposits
Lacustrine deposits are sedimentary rock formations which formed in the bottom of ancient lakes. A common characteristic of lacustrine deposits is that a river or stream channel has carried sediment into the basin. Lacustrine deposits form in all lake types including rift graben lakes, oxbow lakes, glacial lakes, and crater lakes. Lacustrine environments, like seas, are large bodies of water. They share similar sedimentary deposits which are mainly composed of low-energy particle sizes. Lacustrine deposits are typically very well sorted with highly laminated beds of silts, clays, and occasionally carbonates. In regards to geologic time, lakes are temporary and once they no longer receive water, they dry up and leave a formation. Lake types Lacustrine deposits can form in every variety of basins found in nature. How each basin originates is where the distinction between lacustrine deposit types stem. Rift graben lakes are formed from crustal stretching also known as rifting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatomaceous Earth
Diatomaceous earth ( ), also known as diatomite ( ), celite, or kieselguhr, is a naturally occurring, soft, siliceous rock, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging from more than 3 millimeter, mm to less than 1 micrometre, μm, but typically 10 to 200 μm. Depending on the granularity, this powder can have an abrasive feel, similar to pumice powder, and has a low density as a result of its high porosity. The typical chemical composition of oven-dried diatomaceous earth is 80–90% silica, with 2–4% aluminum oxide, alumina (attributed mostly to clay minerals), and 0.5–2% iron oxide. Diatomaceous earth consists of the fossilized remains of diatoms, a type of hard-shelled microalgae, that have accumulated over millions of years. It is used as a filtration aid, mild abrasive in products including metal polishes and toothpaste, mechanical insecticide, absorption (chemistry), absorbent for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eolianite
Eolianite or aeolianite is any rock formed by the lithification of sediment deposited by aeolian processes; that is, the wind. In common use, however, the term refers specifically to the most common form of eolianite: coastal limestone consisting of carbonate sediment of shallow Marine (ocean), marine biogenic origin, formed into coastal dunes by the wind, and subsequently lithified. It is also known as kurkar in the Middle East, miliolite in India and Arabia, and grès dunaire in the eastern Mediterranean. eolianite has a hardness of 4.3 and is very dull. Streak is light brown. Description Sayles coined the term in 1931, when he described the dune-shaped hills of Bermuda, consisting of bioclastic grainstones. Thus, Bermuda is considered the type locality (geology), type locality for carbonate eolianite facies, with clearly defined cross-bedding, foresets, and topsets. Deposition is controlled by glacio-eustatic changes, with eolianites forming during interglaciations. Eolian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quaternary
The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS), as well as the current and most recent of the twelve periods of the Phanerozoic eon. It follows the Neogene Period and spans from 2.58 million years ago to the present. The Quaternary Period is divided into two epochs: the Pleistocene (2.58 million years ago to 11.7 thousand years ago) and the Holocene (11.7 thousand years ago to today); a proposed third epoch, the Anthropocene, was rejected in 2024 by IUGS, the governing body of the ICS. The Quaternary is typically defined by the Quaternary glaciation, the cyclic growth and decay of continental ice sheets related to the Milankovitch cycles and the associated climate and environmental changes that they caused. Research history In 1759 Giovanni Arduino proposed that the geological strata of northern Italy could be divided into four succ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precambrian
The Precambrian ( ; or pre-Cambrian, sometimes abbreviated pC, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic Eon, which is named after Cambria, the Latinized name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time. The Precambrian is an informal unit of geologic time, subdivided into three eons ( Hadean, Archean, Proterozoic) of the geologic time scale. It spans from the formation of Earth about 4.6 billion years ago ( Ga) to the beginning of the Cambrian Period, about million years ago ( Ma), when hard-shelled creatures first appeared in abundance. Overview Relatively little is known about the Precambrian, despite it making up roughly seven-eighths of the Earth's history, and what is known has largely been discovered from the 1960s onwards. The Precambrian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Shield
The Western Ethiopian Shield is a small geological shield along the western border of Ethiopia. Its plutons were formed between 830 and 540 million years ago. See also *Craton * Platform *Basement A basement is any Storey, floor of a building that is not above the grade plane. Especially in residential buildings, it often is used as a utility space for a building, where such items as the Furnace (house heating), furnace, water heating, ... * Platform basement References Shields (geology) Geology of Africa Geology of Ethiopia {{plate-tectonics-stub lv:Arābijas-Nūbijas vairogs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chad Basin
The Chad Basin is the largest endorheic basin in Africa, centered approximately on Lake Chad. It has no outlet to the sea and contains large areas of semi-arid desert and savanna. The drainage basin is approximately coterminous with the sedimentary basin of the same name, but extends further to the northeast and east. The basin spans four modern nations, including most of Chad and a large part of Niger, Nigeria and Cameroon. A combination of dams, increased irrigation, climate change, and reduced rainfall are causing water shortages. Lake Chad continues to shrink. Geology The geological basin, which is smaller than the drainage basin, is a Phanerozoic sedimentary basin formed during the plate divergence that opened the South Atlantic Ocean. The basin lies between the West African craton, West African Craton and Congo craton, Congo Craton, and formed about the same time as the Benue Trough. It covers an area of about . It merges into the Iullemmeden Basin to the west at the Dame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
