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79-661: The original homeland of Proto-South Cushitic was in Southwest Ethiopia. South Cushitic speakers then migrated south to lake Turkana and further south, entering Tanzania in 2000BC. The Rift languages are named after the Great Rift Valley of Tanzania, where they are found. Hetzron (1980:70ff) suggested that the Rift languages (South Cushitic) are a part of Lowland East Cushitic . Kießling & Mous (2003) have proposed more specifically that they be linked to

158-492: A Hungarian and an Austrian , on 6 March 1888. They were the first Europeans to have recorded visiting the lake after a long safari across East Africa. The lake kept its European name during the colonial period of British East Africa . However, the existence of the lake and its shape and location were well known in Europe long before Teleki conceived of his visit. At some unknown time, the lake acquired an alternative name as

237-420: A laboratory or factory . Mining in a wider sense comprises extraction of any resource (e.g. petroleum , natural gas , salt or even water ) from the earth. Mining of rock and metals has been done since prehistoric times. Modern mining processes involve prospecting for mineral deposits, analysis of the profit potential of a proposed mine, extraction of the desired materials, and finally reclamation of

316-541: A nameplate capacity of 850 kilowatts. As of October 2016 155 turbines had been installed with completion expected in 2017. It will be the largest wind power project in Africa. Full commercial operation achieved in March 2019. 100% Capacity Factor (meaning full 310 MW generated) achieved in March 2021. The Gibe III dam is already under construction by Ethiopia along its Omo River, with general recognition that it will cause

395-437: A 1968 study by Alistair Graham. The lake also has a large population of large water turtles, particularly in the area of Central Island. The Turkana mud turtle is endemic to the lake. Over the dry grasslands ranges a frail population of grazing mammals and predators. The grazers are chiefly Grevy's zebra , Burchell's zebra , the beisa oryx , Grant's gazelle , the topi and the reticulated giraffe . They are hunted by

474-483: A Southern Lowland branch, together with Oromo , Somali , and Yaaku–Dullay . It is possible that the great lexical divergence of Rift from East Cushitic is due to Rift being partially influenced through contact with Khoisan languages , as perhaps evidenced by the unusually high frequency of the ejective affricates /tsʼ/ and /tɬʼ/ , which outnumber pulmonary consonants like /p, f, w, ɬ, x/ . Kießling & Mous suggest that these ejectives may be remnants of clicks from

553-646: A Southern West Rift language. Aasax and Kw'adza are poorly attested and, like Dahalo, maybe the result language shift from non-Cushitic languages. Several additional and now extinct South Cushitic languages are deduced from their influence on the Bantu languages that replaced them. Two of these, Taita Cushitic , appear to have been more distinct from the current Rift languages than other related languages. They are similar to an earlier form of Rift, which Nurse (1988) calls "Greater Rift". Lake Turkana Lake Turkana ( / t ɜːr ˈ k ɑː n ə , - ˈ k æ n -/ )

632-536: A dry riverbed, the Lomekwi 3 site recovered primitive hammers, anvils, and cutting tools.  However, the emergence of Acheulean technology no longer assumes that tool use was a distinguishing factor among Homo species as Australopithecus afarensis were also using simple tools prior to the appearance of the genus Homo , over 3.3 million years ago. Australopithecus anamensis fossils discovered by Meave Leakey in 1994 date to around 4 million years ago, setting

711-402: A fourth class of rocks alongside igneous, sedimentary, and metamorphic. Rock varies greatly in strength, from quartzites having a tensile strength in excess of 300 MPa to sedimentary rock so soft it can be crumbled with bare fingers (that is, it is friable ). (For comparison, structural steel has a tensile strength of around 350 MPa. ) Relatively soft, easily worked sedimentary rock

790-418: A further drop in the lake level.[29] Friends of Lake Turkana, a Kenyan organisation representing indigenous groups in northwestern Kenya whose livelihoods are linked to Lake Turkana, had previously estimated that the dam could reduce the level of Lake Turkana by up to 10 meter affecting up to 300,000 people.[30] This could cause the brackish water to increase in salinity to where it may no longer be drinkable by

869-649: A high risk for a magnitude 7 or 8 earthquake in the Gibe III dam region. The magnitude of the impact that the dam and possible irrigation projects induced by the dam will have on the water level of Lake Turkana is controversial. A hydrological study conducted for the African Development Bank in November 2010 concluded that the filling of the dam will reduce the lake's water level by two metres, if no irrigation will be undertaken. Irrigation would cause

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948-433: A huge impact on the cultural and technological development of the human race. Rock has been used by humans and other hominids for at least 2.5 million years . Lithic technology marks some of the oldest and continuously used technologies. The mining of rock for its metal content has been one of the most important factors of human advancement, and has progressed at different rates in different places, in part because of

1027-536: A major decrease in river flow downstream and a serious reduction of inflow to Kenya's Lake Turkana, which receives 90 per cent of its waters from the river. According to the ARWG [citation needed] report, these changes will destroy the survival means of at least 200,000 pastoralists, flood-dependent agriculturalists and fishers along the Omo River 300,000 pastoralists and fishers around the shores of Lake Turkana – plunging

1106-564: A profound influence on the level of Lake Turkana and adjacent water bodies. The archaeoastronomical site Namoratunga which has been dated circa 300 BC is located near Lake Turkana. Hominin fossils of some of the earliest human ancestors have been found in the Turkana Basin. Lake Turkana is considered the cradle of human life because of the diverse hominid species found living millions of years apart, in this desert landscape.  These fossils have facilitated our understanding of

1185-562: A source area and then transported to the place of deposition by water , wind , ice , mass movement or glaciers (agents of denudation ). About 7.9% of the crust by volume is composed of sedimentary rocks, with 82% of those being shales, while the remainder consists of 6% limestone and 12% sandstone and arkoses . Sedimentary rocks often contain fossils . Sedimentary rocks form under the influence of gravity and typically are deposited in horizontal or near horizontal layers or strata , and may be referred to as stratified rocks. Sediment and

1264-436: A source of diseases spread by contaminated water. Increasingly, communities on the lake's shores rely on underground springs for drinking water. The same characteristics that make it unsuitable for drinking limit its use in irrigation . The climate is hot and very dry. The rocks of the surrounding area are predominantly volcanic . Central Island is an active volcano, emitting vapour. Outcrops and rocky shores are found on

1343-713: A texture are referred to as foliated ; the remainders are termed non-foliated. The name of the rock is then determined based on the types of minerals present. Schists are foliated rocks that are primarily composed of lamellar minerals such as micas . A gneiss has visible bands of differing lightness , with a common example being the granite gneiss. Other varieties of foliated rock include slates , phyllites , and mylonite . Familiar examples of non-foliated metamorphic rocks include marble , soapstone , and serpentine . This branch contains quartzite —a metamorphosed form of sandstone —and hornfels . Though most understanding of rocks comes from those of Earth, rocks make up many of

1422-538: Is a saline lake in the Kenyan Rift Valley , in northern Kenya , with its far northern end crossing into Ethiopia . It is the world's largest permanent desert lake and the world's largest alkaline lake . By volume it is the world's fourth-largest salt lake after the Caspian Sea , Issyk-Kul , and Lake Van (passing the shrinking South Aral Sea ), and among all lakes it ranks 24th. Lake Turkana

1501-608: Is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition , and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust , and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere . The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy . It may be limited to rocks found on Earth, or it may include planetary geology that studies

1580-458: Is formed through the cooling and solidification of magma or lava . This magma may be derived from partial melts of pre-existing rocks in either a planet 's mantle or crust . Typically, the melting of rocks is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Igneous rocks are divided into two main categories: Magmas tend to become richer in silica as they rise towards

1659-442: Is next in importance. About 65% of the Earth's crust by volume consists of igneous rocks. Of these, 66% are basalt and gabbro , 16% are granite, and 17% granodiorite and diorite . Only 0.6% are syenite and 0.3% are ultramafic . The oceanic crust is 99% basalt, which is an igneous rock of mafic composition. Granite and similar rocks, known as granitoids , dominate the continental crust . Sedimentary rocks are formed at

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1738-586: Is now threatened by the construction of the Gilgel Gibe III Dam in Ethiopia due to the damming of the Omo river which supplies most of the lake's water. Although the lake commonly has been—and to some degree still is—used for drinking water, its salinity (slightly brackish ) and very high levels of fluoride (much higher than in fluoridated water ) generally make it unsuitable, and it has also been

1817-406: Is sensitive to climatic and seasonal fluctuations. For purposes of comparison, the historic level of Lake Turkana declined from a high of 20m above today's level in the 1890s to the same level as today in the 1940s and 1950s. Then it increased again gradually by 7 metres to reach a peak around 1980, and subsequently decreased again.[31] The Environmental and Social Impact Assessment (ESIA) summary of

1896-453: Is the study of Earth and its components, including the study of rock formations. Petrology is the study of the character and origin of rocks. Mineralogy is the study of the mineral components that create rocks. The study of rocks and their components has contributed to the geological understanding of Earth's history, the archaeological understanding of human history, and the development of engineering and technology in human society. While

1975-696: The Jade Sea from its turquoise colour seen approaching from a distance. The colour comes from algae that rise to the surface in calm weather. This is likely also a European name. J. W. Gregory reported in The Geographical Journal of 1894 that it was called "Basso Narok", meaning "Black Lake" in the Samburu language . Likewise, the nearby Ethiopian Lake Chew Bahir is called "Basso Naibor" in Samburu, meaning "White Lake". The Samburu are among

2054-677: The Turkana Basin . The highest is 100 m above the surface of the lake (only approximate, as the lake level fluctuates), which occurred about 9500 years ago, at the end of the Pleistocene as part of the African humid period . It is generally theorised that Turkana was part of the upper Nile system at that time, connecting to Lake Baringo at the southern end and the White Nile in the north, and that volcanic land adjustments severed

2133-417: The history of geology includes many theories of rocks and their origins that have persisted throughout human history, the study of rocks was developed as a formal science during the 19th century. Plutonism was developed as a theory during this time, and the discovery of radioactive decay in 1896 allowed for the radiocarbon dating of rocks. Understanding of plate tectonics developed in the second half of

2212-495: The little stint , the wood sandpiper , and the common sandpiper . The African skimmer ( Rhyncops flavirostris ) nests in the banks of Central Island. The white-breasted cormorant ( Phalacrocorax lucidus ) ranges over the lake, as do many other waterbirds. The greater flamingo wades in its shallows. Heuglin's bustard ( Neotis heuglinii ) is found in the east of the lake region. The lake formerly contained Africa's largest population of Nile crocodiles : 14,000, as estimated in

2291-574: The mantle , began separating from the rest of Africa, moving to the northeast. Currently, the graben is 320 km wide in the north of the lake, 170 km in the south. This rift is one of two, and is called the Great or Eastern Rift. There is another to the west, the Western Rift. Lake Turkana is a unique feature of the East African landscape. Besides being a permanent desert lake, it is

2370-399: The 20th century. Rocks are composed primarily of grains of minerals, which are crystalline solids formed from atoms chemically bonded into an orderly structure. Some rocks also contain mineraloids , which are rigid, mineral-like substances, such as volcanic glass , that lack crystalline structure. The types and abundance of minerals in a rock are determined by the manner in which it

2449-467: The Earth's surface, a process called magma differentiation . This occurs both because minerals low in silica crystallize out of the magma as it begins to cool ( Bowen's reaction series ) and because the magma assimilates some of the crustal rock through which it ascends ( country rock ), and crustal rock tends to be high in silica. Silica content is thus the most important chemical criterion for classifying igneous rock. The content of alkali metal oxides

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2528-503: The Earth's surface: temperatures greater than 150 to 200 °C and pressures greater than 1500 bars. This occurs, for example, when continental plates collide. Metamorphic rocks compose 27.4% of the crust by volume. The three major classes of metamorphic rock are based upon the formation mechanism. An intrusion of magma that heats the surrounding rock causes contact metamorphism—a temperature-dominated transformation. Pressure metamorphism occurs when sediments are buried deep under

2607-603: The Turkana land. The area is primarily clay-based and is more alkaline than seawater. After the independence of Kenya , the president, Mzee Jomo Kenyatta , renamed it in 1975 after the Turkana , the predominant tribe there. The Turkana refer to the lake as Anam Ka'alakol , meaning "the sea of many fish". It is from the name Ka'alakol that Kalokol , a town on the western shore of Lake Turkana, east of Lodwar , derives its name. The previous indigenous Turkana name for Lake Turkana

2686-607: The area around Lake Turkana, which is evidence for numerous migrations of diverse people over thousands of years. The current language groups include at least three separate subgroups of the Nilotic ( Nilo-Saharan ) and Cushitic ( Afro-Asiatic ) language families, which have further subdivided into more than 12 languages surrounding the lake today. In the early Holocene (during the Holocene Climatic Optimum ), lake levels were high and fishing and foraging were

2765-403: The beginning date of bipedalism back half a million years. Richard Leakey has led numerous anthropological expeditions in the area which have led to many important discoveries of hominin remains. The two-million-year-old skull 1470 was found in 1972. It was originally thought to be Homo habilis , but the scientific name Homo rudolfensis , derived from the old name of this lake (Rudolf)

2844-520: The cichlids Haplochromis macconneli , H. rudolfianus , H. turkanae and Hemichromis exsul , the barb Enteromius turkanae , the catfish Chrysichthys turkana , the robber tetras Brycinus ferox and B. minutus , the Rudolf lates Lates longispinis , the lampeyes Lacustricola jeanneli and Micropanchax rudolfianus , and the cyprinid Neobola stellae . Non-endemics include species such as Nile tilapia , mango tilapia , bichirs ,

2923-632: The connection. Such a hypothesis explains the Nile species in the lake, such as the crocodiles and the Nile perch. High water levels also occurred approximately 9000, 6000 and 5000 years ago, each of which were followed by drops in lake level of more than 40m in less than 200 years. It is thought that changes in the position of the Congo Air Boundary affected the ability of moisture from the Atlantic Ocean to reach eastern Africa, which had

3002-523: The constituent particles, and particle size . These physical properties are the result of the processes that formed the rocks. Over the course of time, rocks can be transformed from one type into another, as described by a geological model called the rock cycle . This transformation produces three general classes of rock: igneous , sedimentary and metamorphic . Those three classes are subdivided into many groups. There are, however, no hard-and-fast boundaries between allied rocks. By increase or decrease in

3081-483: The dominant tribes in the lake Turkana region when the explorers came." What the native form of this phrase was, what it might mean, and in which language is not clear. The major biomes are the lake itself, which is an aquatic biome, and the surrounding region, which is classified as desert and xeric shrubland . The Chalbi Desert is east of the lake. During moister times, a dry grassland appears, featuring Aristida adcensionis and A. mutabilis . During drier times,

3160-436: The dynamic human evolution process and implies that they descended from more than one common ancestor, diverging into multiple lineages. The changing forest environment forced the early humans to adapt to a more open grassland that increased their exposure to threatening predators. Volcanic ash and drier climates were ideal for preserving these human fossils but it also caused the lake to shrink or disappear at times.  In

3239-496: The earliest humans. This early period, called the Stone Age , saw the development of many stone tools. Stone was then used as a major component in the construction of buildings and early infrastructure . Mining developed to extract rocks from the Earth and obtain the minerals within them, including metals . Modern technology has allowed the development of new human-made rocks and rock-like substances, such as concrete . Geology

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3318-606: The earth's surface by the accumulation and cementation of fragments of earlier rocks, minerals, and organisms or as chemical precipitates and organic growths in water ( sedimentation ). This process causes clastic sediments (pieces of rock) or organic particles ( detritus ) to settle and accumulate or for minerals to chemically precipitate ( evaporite ) from a solution . The particulate matter then undergoes compaction and cementation at moderate temperatures and pressures ( diagenesis ). Before being deposited, sediments are formed by weathering of earlier rocks by erosion in

3397-427: The earth, from an ore body, vein or seam . The term also includes the removal of soil. Materials recovered by mining include base metals , precious metals , iron , uranium , coal , diamonds , limestone , oil shale , rock salt , potash , construction aggregate and dimension stone . Mining is required to obtain any material that cannot be grown through agricultural processes, or created artificially in

3476-521: The east and south shores of the lake, while dunes, spits and flats are on the west and north, at a lower elevation. On-shore and off-shore winds can be extremely strong, as the lake warms and cools more slowly than the land. Sudden, violent storms are frequent. Three rivers (the Omo , Turkwel and Kerio ) flow into the lake, but lacking outflow , its only water loss is by evaporation. Lake volume and dimensions are variable. For example, its level fell by 10 m (33 ft) between 1975 and 1993. Despite

3555-562: The eastern shore at the Nataruk Site, this region provides considerable insight to the way these early humans thrived and survived the inconsistent climate along the lake shore and beyond.   Homo erectus is the closest of Homo sapiens ' ancestors and contended to be the first hominin to cross the Levantine corridor out of Africa, into Europe and Asia 1.8 million years ago.   Many language groups are represented in

3634-538: The elephantfish Mormyrus kannume , African arowana , African knifefish , Distichodus niloticus , the Nile perch and numerous others. During the early Holocene , the water level of the lake was higher, and it overflowed into the Nile River, allowing fish and crocodiles access. Consequently, the non-endemic fishes in the lake are mainly riverine species of Nilotic origin. Some of the non-endemics do not breed in

3713-577: The firm that builds the dam this would reduce the water level in the lake by "less than 50 cm per year for three years" and that salinity "will not change in any way".[26] According to the International Lake Environment Committee, 90% of Lake Turkana's water is delivered by the Omo River on which the Dam would be built.[31] With no outlet, Lake Turkana loses 2.3 meters of water every year to evaporation, and its level

3792-695: The grass disappears. The shrublands contain dwarf shrubs, such as Duosperma eremophilum and Indigofera spinosa . Near the lake are doum palms . Both phytoplankton and zooplankton are found in the lake. Of the former, cyanobacteria are represented by Microcystis aeruginosa and microalgae by Botryococcus braunii . Also present are Anabaenopsis arnoldii , Planctonema lauterbornii , Oocystis gigas , Sphaerocystis schroeteri , and some others. The zooplankton includes copepods , cladocerans and protozoans . Compared to other large African lakes, Turkana has relatively few fish species. The lake holds about 50 fish species, including 12 endemics :

3871-402: The ground; pressure is dominant, and temperature plays a smaller role. This is termed burial metamorphism, and it can result in rocks such as jade . Where both heat and pressure play a role, the mechanism is termed regional metamorphism. This is typically found in mountain-building regions. Depending on the structure, metamorphic rocks are divided into two general categories. Those that possess

3950-441: The indigenous groups around the lake. Currently, the salinity of the water is about 2332 mg/L, and it is estimated that a 10-meter decrease in the water level of Lake Turkana could cause the salinity to rise to 3397 mg/L.[20] Raising salinity could also drastically reduce the number of fish in the lake, which the people around Lake Turkana depend on for sustenance and their livelihoods. According to critics, this "will condemn

4029-491: The kind of metals available from the rock of a region. Anthropic rock is synthetic or restructured rock formed by human activity. Concrete is recognized as a human-made rock constituted of natural and processed rock and having been developed since Ancient Rome . Rock can also be modified with other substances to develop new forms, such as epoxy granite . Artificial stone has also been developed, such as Coade stone . Geologist James R. Underwood has proposed anthropic rock as

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4108-427: The lack of outflow, in ecology it is often regarded as a part of—or at least associated with—the Nile basin because of its prehistoric connection to this system and the similarities in their aquatic faunas . Due to temperature (its surface water typically is 27–31 °C [81–88 °F] and the mean air temperature of the region generally is similar or slightly higher), aridity and geographic inaccessibility,

4187-418: The lake retains its wild character. Nile crocodiles are found in great abundance on the flats. The rocky shores are home to scorpions and carpet vipers . The lake is rich in fish and fishing is very important to the local economy, but this is threatened by falling water levels and overfishing . Lake Turkana National Parks are now listed as a UNESCO World Heritage Site . Sibiloi National Park lies on

4266-418: The lake to a not-so-slow death."[9] According to dam proponents, the impact on Lake Turkana will be limited to the temporary reduction in flows during the filling of the reservoir. Various sources state that the filling could take between one and three wet seasons.[9][26] The total storage volume of the reservoir of Gibe III dam will be between 11.75 and 14 billion cubic meter, depending on sources. According to

4345-459: The lake's eastern shore, while Central Island National Park and South Island National Park lie in the lake. Both are known for their Nile crocodiles. An abundance of hominid fossils have been discovered in the area surrounding Lake Turkana. The area still sees few visitors, being two days' drive from Nairobi . The lake is also an imaginary boundary of the Rendille and Borana and Oromo to

4424-476: The lake, but migrate up the Omo River and other affluents to breed. The lake is heavily fished. The Lake Turkana region is home to hundreds of species of birds native to Kenya . The East African Rift System also serves as a flyway for migrating birds, bringing in hundreds more. The birds are essentially supported by plankton masses in the lake, which also feed the fish. Some birds more common to Turkana are

4503-431: The land to prepare it for other uses once mining ceases. Mining processes may create negative impacts on the environment both during the mining operations and for years after mining has ceased. These potential impacts have led to most of the world's nations adopting regulations to manage negative effects of mining operations. Stone tools have been used for millions of years by humans and earlier hominids . The Stone Age

4582-494: The lion and the cheetah . Elephants and the black rhinoceroses are no longer seen, although Teleki reported seeing (and shooting) many. Closer to the dust is the cushioned gerbil ( Gerbillus pulvinatus ). Lake Turkana is an East African Rift feature. A rift is a weak place in the Earth's crust due to the separation of two tectonic plates , often accompanied by a graben , or trough, in which lake water can collect. The rift began when East Africa, impelled by currents in

4661-417: The only lake that retains the waters originating from two separate catchment areas of the Nile . The Lake Turkana drainage basin draws its waters mainly from Kenya Highlands and Ethiopian Highlands . The basement rocks of the region have been dated by two analytical determinations to 522 and 510 million years ago (mya). No rift was in the offing at that time. A rift is signalled by volcanic activity through

4740-418: The original rock was formed. This process is called metamorphism , meaning to "change in form". The result is a profound change in physical properties and chemistry of the stone. The original rock, known as the protolith , transforms into other mineral types or other forms of the same minerals, by recrystallization . The temperatures and pressures required for this process are always higher than those found at

4819-856: The outcrops forming the rocky mountains and badlands around the lake. In the Omo portion of the basin, of the Mursi Basalts, the Mursi Formation is on the west side of the Omo, the Nkalabong on the Omo, and the Usno and Shungura east of the Omo. Probably the best known of the formations are the Koobi Fora on the east side of Turkana and the Nachukui on the west. Short-term fluctuations in lake level combined with periodic volcanic ash spewings over

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4898-425: The particles of clastic sedimentary rocks can be further classified by grain size . The smallest sediments are clay , followed by silt , sand , and gravel . Some systems include cobbles and boulders as measurements. Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which

4977-478: The period when domesticated animals were first introduced to the region about 5000 years ago, while later, the dead were buried in small grave cairns. People who live in the region today commonly practice mixed subsistence, switching between hunting, fishing and animal herding based on what is feasible in a given year. However, the construction of infrastructure like Christian missionary stations, energy extraction (wind, oil) and NGO aid distribution points have made

5056-433: The primary subsistence economies. This was mostly supplanted by animal-based agriculture by 5000 years ago, when the lake level was in a period of rapid fluctuation. During the later Holocene , human responses to climatic changes included intensive fishing when lake level was high and a shift to cattle herding when the level dropped. Megalithic graves are found widely distributed on the lake shores and appear to correspond to

5135-440: The project did not assess the impact of the dam on the water level and water quality of Lake Turkana.[32] The director of Kenya's Water Services Regulatory Board, John Nyaoro, argued that the dam would have no negative impact on Lake Turkana.[33] A Kenya Government report in 2021 estimated that the surface area of Lake Turkana had increased by 10% between 2010 and 2020. Rock (geology) In geology , rock (or stone )

5214-466: The proportions of their minerals, they pass through gradations from one to the other; the distinctive structures of one kind of rock may thus be traced, gradually merging into those of another. Hence the definitions adopted in rock names simply correspond to selected points in a continuously graduated series. Igneous rock (derived from the Latin word igneus, meaning of fire, from ignis meaning fire)

5293-494: The region have resulted in a fortuitous layering of the ground cover over the basal rocks. These horizons can be dated more precisely by chemical analysis of the tuff . As this region is believed to have been an evolutionary nest of hominins , the dates are important for generating a diachronic array of fossils, both hominoid and nonhominoid—that is, both ape (includes hominins) and non-ape . Many thousands have been excavated. Terraces representing ancient shores are visible in

5372-416: The region more connected to and dependent on outside resources for subsistence. Traditional modes of subsistence like pastoralism and fishing are now supplemented by the cash-based economy. The Lake Turkana Wind Power consortium (LTWP) plans to provide 310 MW of power to Kenya's national electricity grid by tapping the unique wind conditions around the lake. The plan calls for 365 wind turbines , each with

5451-426: The region's ethnic groups into cross-border violent conflict reaching well into South Sudan, as starvation confronts all of them. The report offers a devastating look at a deeply flawed development process fuelled by the special interests of global finance and African governments. In the process, it identifies major overlooked or otherwise minimised risks, not the least of which is a U.S. Geological Survey estimation of

5530-641: The rocks of other celestial objects. Rocks are usually grouped into three main groups: igneous rocks , sedimentary rocks and metamorphic rocks . Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments , which in turn are formed by the weathering , transport, and deposition of existing rocks. Metamorphic rocks are formed when existing rocks are subjected to such high pressures and temperatures that they are transformed without significant melting. Humanity has made use of rocks since

5609-460: The shore of an ancient and larger Lake Turkana, and where numerous human skeletons showing major traumatic injuries to the head, neck, ribs, knees and hands are argued to be evidence of inter-group conflict between nomadic hunter-gatherers 10,000 years ago. With over 230 individuals found at the Koobi Fora site along the western shore, and scattered Homo sapiens skeletons with bone marks along

5688-880: The source language. The terms "South Cushitic" and "Rift" are not quite synonymous: The Ma'a and Dahalo languages were once included in South Cushitic, but were not considered Rift. Kießling restricts South Cushitic to West Rift as its only indisputable branch. He states that Dahalo has too many East Cushitic features to belong to South Cushitic, as does Ma'a. (The Waata and Degere may once have spoken languages similar to Dahalo.) He deems Kw'adza and Aasax in turn insufficiently described to classify as even Cushitic with any certainty. Gorowa Iraqw Alagwa Burunge Aasáx (extinct) Kw'adza (extinct) Iraqw and Gorowa are close enough for basic mutual intelligibility . Alagwa has become similar to Burunge through intense contact, and so had previously been classified as

5767-621: The universe's celestial bodies. In the Solar System , Mars , Venus , and Mercury are composed of rock, as are many natural satellites , asteroids , and meteoroids . Meteorites that fall to Earth provide evidence of extraterrestrial rocks and their composition. They are typically heavier than rocks on Earth. Asteroid rocks can also be brought to Earth through space missions, such as the Hayabusa mission. Lunar rocks and Martian rocks have also been studied. The use of rock has had

5846-714: The weakened crust. The oldest volcanic activity of the region occurred in the Nabwal Hills northeast of Turkana and is dated to 34.8 mya in the late Eocene . The visible tectonic features of the region result from extensive extrusions of basalt over the Turkana-Omo basin in the window 4.18–3.99 mya. These are called the Gombe Group Basalts. They are subdivided into the Mursi Basalts and the Gombi Basalts. The two latter basalts are identified as

5925-456: Was Anam a Cheper . Natives who live around Lake Turkana include the Turkana , Rendille , Gabbra , Daasanach , Hamar Koke, Karo, Nyagatom, Mursi , Surma , and Molo peoples. For the location of many of these peoples, refer to the dialect map in the article. The lake was originally named Lake Rudolf (in honour of Crown Prince Rudolf of Austria ) by Count Sámuel Teleki de Szék and his second-in-command Lieutenant Ludwig Ritter Von Höhnel ,

6004-408: Was a period of widespread stone tool usage. Early Stone Age tools were simple implements, such as hammerstones and sharp flakes. Middle Stone Age tools featured sharpened points to be used as projectile points , awls, or scrapers . Late Stone Age tools were developed with craftsmanship and distinct cultural identities. Stone tools were largely superseded by copper and bronze tools following

6083-456: Was formed. Most rocks contain silicate minerals , compounds that include silica tetrahedra in their crystal lattice , and account for about one-third of all known mineral species and about 95% of the earth's crust . The proportion of silica in rocks and minerals is a major factor in determining their names and properties. Rocks are classified according to characteristics such as mineral and chemical composition, permeability , texture of

6162-470: Was proposed in 1986 by V. P. Alexeev. In 1984, the Turkana Boy , a nearly complete skeleton of a Homo ergaster juvenile, was discovered by Kamoya Kimeu . More recently, Meave Leakey discovered a 3.5 million-year-old skull there, designated Kenyanthropus platyops ("the flat-faced man of Kenya"). Marta Mirazón Lahr discovered early evidence of human warfare at the site of Nataruk , located near

6241-736: Was quarried for construction as early as 4000 BCE in Egypt, and stone was used to build fortifications in Inner Mongolia as early as 2800 BCE. The soft rock, tuff , is common in Italy, and the Romans used it for many buildings and bridges. Limestone was widely used in construction in the Middle Ages in Europe and remained popular into the 20th century. Mining is the extraction of valuable minerals or other geological materials from

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