Misplaced Pages

#424575

25-603: Karakum may refer to: Karakum Desert , a desert in Central Asia Aral Karakum Desert Karakum (film) , a 1994 Turkmen film Karakum Canal , Turkmenistan Karakum District , Turkmenistan See also [ edit ] Karakoram , a large mountain range spanning the borders of India, Pakistan and China Karakorum , a medieval city in Mongolia Topics referred to by

50-943: A distance of 432 kilometers, traces approximately half of its course along the historic path of the Uzboy River . The Great Turkmen Collector starts in Lebap Province and is 720 km (450 mi) long. They are used for pumping run-off water from irrigated cotton fields towards the lake. Evaporite An evaporite ( / ɪ ˈ v æ p ə ˌ r aɪ t / ) is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution . There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments . Although all water bodies on

75-661: A few percent of evaporite minerals, the remainder being composed of the more typical detrital clastic rocks and carbonates . Examples of evaporite formations include occurrences of evaporite sulfur in Eastern Europe and West Asia. For a formation to be recognised as evaporitic it may simply require recognition of halite pseudomorphs , sequences composed of some proportion of evaporite minerals, and recognition of mud crack textures or other textures . Evaporites are important economically because of their mineralogy, their physical properties in-situ, and their behaviour within

100-437: A picture into past Earth climates. Some particular deposits even show important tectonic and climatic changes. These deposits also may contain important minerals that help in today's economy. Thick non-marine deposits that accumulate tend to form where evaporation rates will exceed the inflow rate, and where there is sufficient soluble supplies. The inflow also has to occur in a closed basin, or one with restricted outflow, so that

125-594: A pluvial period led to overflow to the Zeravshan River valley to the east. The two flows merged and formed or expanded Horezm Lake, which had been formed by the earlier Khvalinian period, and as it overflowed northwards it carved its link with the Aral Sea along the Akcha Dar'ya population corridor of that low, gentle valley (a remote community of Western Uzbekistan and north-east Turkmenistan). The sands of

150-491: Is a chart that shows minerals that form the marine evaporite rocks. They are usually the most common minerals that appear in this kind of deposit. Evaporite minerals start to precipitate when their concentration in water reaches such a level that they can no longer exist as solutes . The minerals precipitate out of solution in the reverse order of their solubilities, such that the order of precipitation from sea water is: The abundance of rocks formed by seawater precipitation

175-408: Is different from Wikidata All article disambiguation pages All disambiguation pages Karakum Desert The population is sparse, with an average of one person per 6.5 km (2.5 sq mi). Rainfall is also rare, ranging from 70 to 150 mm (3 to 6 in) per year. The desert covers roughly seventy percent of Turkmenistan , a long east–west swath. It sits east of

200-466: Is in the same order as the precipitation given above. Thus, limestone (dolomite are more common than gypsum , which is more common than halite, which is more common than potassium and magnesium salts. Evaporites can also be easily recrystallized in laboratories in order to investigate the conditions and characteristics of their formation. Recent evidence from satellite observations and laboratory experiments suggest evaporites are likely present on

225-736: The Caspian Sea which has a steep east bank. It adjoins, to the north, the long delta feeding the South Aral Sea further north, another endorheic lake , about 58 m (190 ft) higher than the Caspian Sea. The delta is that of the Amu Darya river to the northeast, demarcating the long border with the Kyzylkum Desert of Uzbekistan . The desert is divided into three regions, the elevated northern Trans-Unguz Karakum,

250-722: The Great Salt Lake in Utah and the Dead Sea , which lies between Jordan and Israel. Evaporite depositional environments that meet the above conditions include: The most significant known evaporite depositions happened during the Messinian salinity crisis in the basin of the Mediterranean . Evaporite formations need not be composed entirely of halite salt. In fact, most evaporite formations do not contain more than

275-615: The Hindu Kush mountains, flow west, and empty into the desert, providing water for irrigation. The desert is crossed by the second-largest irrigation canal in the world, the Karakum Canal , which brings water from the Amu Darya to southern regions of the desert. Construction on the canal was started in 1954 and completed in 1958. It is 1,375 km (900 mi) in length, and carries 13 to 20 km of water annually. Within

SECTION 10

#1732765847425

300-700: The Aral Karakum are made of finely-dispersed evaporites and remnants of alkaline mineral deposits, washed into the basin from irrigated fields. Wildlife in this area is not very diverse and includes insects and arachnids such as ants , termites , ticks , spiders , dung beetles , and darkling beetles. Lizards , turtles and snakes also live in the Karakum. Bird species include Alauda , desert sparrows , and other species, while rodents include jerboas and gophers . The tolai hare , goitered gazelle , and corsac fox are examples of mammal species in

325-583: The Karakum Desert. The Karakum is home to the Darvaza gas crater . Also called the "Door to Hell" or the "Gates of Hell" by locals, it is a crater of natural gas that has been burning since 1971. The crater is a major tourist attraction, with hundreds of visitors arriving each year. The area has significant oil and natural gas deposits. To the south the Murghab and Tejen rivers flow out of

350-453: The Karakum Desert. Upon completion, the lake will span 2,000 square kilometres (770 sq mi) with a maximum depth of 70 metres (230 ft), and hold more than 130 cubic kilometers (4600 billion cubic feet) of water. Filling the lake could take 15 years and cost up to $ 4.5 billion. According to government plans, it is intended to be filled by a 2,650-kilometer (1,650 mi) network of tributary canals. The Dashoguz Collector, spanning

375-670: The Karakum are the Uly Balkan , a mountain range in which archaeologists have found human remains dating back to the Stone Age . The oases of Mary and Tejen are noted for cotton growing. The desert is crossed by the Trans-Caspian Railway . Golden Age Lake , locally known as Altyn Asyr köli or alternatively as Karakum Lake, is a man-made lake under construction in the Karashor Depression in

400-618: The low-lying Central Karakum, and the southeastern Karakum, home to a chain of salt marshes . Since the early 1980s, the relatively small desert extension, the Aralkum , has come to occupy most of the former seabed of the Aral Sea , about 15,440 sq mi (40,000 km ). The sea has fluctuated over millennia, but its majority loss during the Soviet Union 's existence coincided with great irrigation projects. The North Aral Sea

425-461: The marine environments. Common minerals that are found in these deposits include blödite , borax , epsomite , gaylussite , glauberite , mirabilite , thenardite and trona . Non-marine deposits may also contain halite, gypsum, and anhydrite, and may in some cases even be dominated by these minerals, although they did not come from ocean deposits. This, however, does not make non-marine deposits any less important; these deposits often help to paint

450-591: The original water depth remains. At this point, minor carbonates begin to form. The next phase in the sequence comes when the experiment is left with about 20% of its original level. At this point, the mineral gypsum begins to form, which is then followed by halite at 10%, excluding carbonate minerals that tend not to be evaporites. The most common marine evaporites are calcite , gypsum and anhydrite , halite, sylvite , carnallite , langbeinite , polyhalite , and kainite . Kieserite (MgSO 4 ) may also be included, which often will make up less than four percent of

475-458: The overall content. However, there are approximately 80 different minerals that have been reported found in evaporite deposits, though only about a dozen are common enough to be considered important rock formers. Non-marine evaporites are usually composed of minerals that are not common in marine environments because in general the water from which non-marine evaporite precipitates has proportions of chemical elements different from those found in

500-414: The remaining water is enriched in salts, and they precipitate when the water becomes supersaturated. Marine evaporites tend to have thicker deposits and are usually the focus of more extensive research. When scientists evaporate ocean water in a laboratory, the minerals are deposited in a defined order that was first demonstrated by Usiglio in 1884. The first phase of precipitation begins when about 50% of

525-411: The same term [REDACTED] This disambiguation page lists articles associated with the title Karakum . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Karakum&oldid=1192441624 " Category : Disambiguation pages Hidden categories: Short description

SECTION 20

#1732765847425

550-489: The sediment has time to pool and form in a lake or other standing body of water. Primary examples of this are called "saline lake deposits". Saline lakes includes things such as perennial lakes, which are lakes that are there year-round, playa lakes, which are lakes that appear only during certain seasons, or any other terms that are used to define places that hold standing bodies of water intermittently or year-round. Examples of modern non-marine depositional environments include

575-674: The subsurface. Evaporite minerals, especially nitrate minerals, are economically important in Peru and Chile. Nitrate minerals are often mined for use in the production on fertilizer and explosives . Thick halite deposits are expected to become an important location for the disposal of nuclear waste because of their geologic stability, predictable engineering and physical behaviour, and imperviousness to groundwater. Halite formations are famous for their ability to form diapirs , which produce ideal locations for trapping petroleum deposits. Halite deposits are often mined for use as salt . This

600-399: The surface and in aquifers contain dissolved salts, the water must evaporate into the atmosphere for the minerals to precipitate. For this to happen, the water body must enter a restricted environment where water input into this environment remains below the net rate of evaporation. This is usually an arid environment with a small basin fed by a limited input of water. When evaporation occurs,

625-541: Was partly restored, but the South Aral Sea ebbed to a small-size stasis at its river mouth, which itself dried up by 2014, leaving only fragments of the former sea behind, such as Barsakelmes Lake . Within the north-west edge of the desert used to be a river. In the late Pleistocene , the Amu Darya used to flow beyond the Aral Basin to Sarykamysh Lake then to the Caspian Sea. Sedimentation and floods during

#424575