| Mundafan | |
|---|---|
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  Mundafan | |
| Coordinates | 18°34′N45°20′E / 18.56°N 45.34°E |
| References | [1] |
Mundafan was a former lake in Saudi Arabia, within presently desert-like areas. It formed during the Pleistocene and Holocene, when orbitally mediated changes in climate increased monsoon precipitation in the peninsula, allowing runoff to form a lake with a maximum area of 300 square kilometres (120 sq mi). It was populated by fishes and surrounded by reeds and savanna, which supported human populations.
Mundafan is a lies in the Najran Province of Saudi Arabia, southwest of the Rub' al Khali desert. [2] The climate of the region is arid to hyperarid, with sand and stone deserts dominating the landscape. [3] The name Arabic : Ramlat al-Mundafan means "the buried sands". [4]
The perennial [5] lake had an elongated shape in northwest-southeast direction [6] and reached a maximum depth of 30 metres (98 ft) [7] and extent of 300 square kilometres (120 sq mi) during stages of high water levels, [8] making it one of the largest former lakes of Arabia. [1] It is possible that it was not one contiguous water body, but rather several separate lakes or an extended wetland. The lake was fed by wadis coming from the Asir Mountains to the west [7] and contained freshwater, [9] although there is also evidence for brackish water. [10] Carbonate sediments formed when parts of the lake bed fell dry. [11]
Mussels ( Unio ), snails ( Biomphalaria and Radix ), sponges and submerged stoneworts (a type of algae) lived in the lake, which was fringed by reeds ( Phragmites and Typha ), [5] sedges and marshes. [12] Indirect evidence attests to the existence of fish in the lake. [13] Riparian forests and savannah environments developed around the lake, [14] with trees including possibly palms. Wildfires occasionally burned in the area. The environment was suitable for humans [7] and Mundafan was an important hunting ground for early humans. [15] Aurochs, camels, wild cattle, gazelles, wild goats, hartebeest, hippopotamuses, horses, ostriches, tahr, water buffalo, wild sheep and wild asses lived around the Mundafan lake. [14] [10]
The lake has left sediments made out of clays, marls and silts that form benches and mounds. [2] The sediments reach thicknesses of 24 metres (79 ft). [16] The sparseness of lake deposits has led to some researchers to doubt that the waterbodies were lakes rather than wetlands, but circumstantial fossil evidence strongly implies that the waterbodies were true lakes and that the rarity of lake landforms is primarily a consequence of wind erosion, which removed these landforms after the lakes had dried up. [12]
The Mundafan lake formed in a c.363 square kilometres (140 sq mi) topographical depression formed by wind deflation. To the east rises the Tuwaiq Escarpment, a limestone of Jurassic age. [2] The lake lies within a former river bed that was blocked by dunes [7] or perhaps faulting [17] and might have overflowed northwards if its surface area exceeded 346 square kilometres (134 sq mi). [1] The catchment of the Mundafan lake is comparatively large, leading to the formation of long-lasting (at least 800 years) lakes and the thickest lake deposits of Arabia. [10]
There were two high water stages, one dated to marine isotope stage 5 (MIS 5) c and a (100,000 and 80,000 years ago, respectively [18] ) and the other to the early Holocene between 9,000-6,000 years ago. [2] The minimum surface area of the lake reached c.100 square kilometres (39 sq mi) 100,000 years ago, c.210 square kilometres (81 sq mi) 80,000 years ago and c.58 square kilometres (22 sq mi) during the Holocene; [7] the actual extent of the lake might have been larger, as lake sediments might have been removed by wind after the lake dried up. [1] During the Holocene, the maximum depth may have reached 10 metres (33 ft). [5]
Increased insolation periodically caused the African monsoon to become stronger and reach farther north on the Arabian Peninsula, activating wadis and filling lakes. [7] [19] These wet periods are recorded in stalagmites of Oman and Yemen and in lake sediments. [20] The increased precipitation allowed the growth of vegetation in what today is hostile desert, in turn permitting animals and humans to get established there. [9] Some researchers however advocate that wet periods took place during glacial times. [21]
The past climate and human movements through the interior Arabian Peninsula have come under scientific focus in the 2010s, with suggestions that human populations preferentially migrated during wet periods. [22] Numerous archaeological sites are linked to former lakes. [23] Research at Mundafan was initially hindered by the hostile climate conditions. [24]
There are archaeological sites of Middle Paleolithic to Neolithic age at Mundafan, [2] often near or on former shorelines [25] but also towards the lake interior, implying that the area was occupied even during low water level. [26] Humans at Mundafan were not sedentary and traded with obsidian from Yemen, farther south. [27] The site MDF-61 at the southwestern end of the lake provided an easy access to its environments and was in use for a long time, leading to the accumulation of large amounts of lithic artifacts [28] such as arrowheads [29] similar to these found in the Levant and Africa. [30] These sites demonstrate that Homo sapiens was present in Arabia, endorsing the theory of an out of Africa migration of mankind [15] which constituted its pivotal expansion event. [3]
The Epipalaeolithic Near East designates the Epipalaeolithic in the prehistory of the Near East. It is the period after the Upper Palaeolithic and before the Neolithic, between approximately 20,000 and 10,000 years Before Present (BP). The people of the Epipalaeolithic were nomadic hunter-gatherers who generally lived in small, seasonal camps rather than permanent villages. They made sophisticated stone tools using microliths—small, finely-produced blades that were hafted in wooden implements. These are the primary artifacts by which archaeologists recognise and classify Epipalaeolithic sites.
Lake Mojave is an ancient former lake fed by the Mojave River that, through the Holocene, occupied the Silver Lake and Soda Lake basins in the Mojave Desert of San Bernardino County, California. Its outlet may have ultimately emptied into the Colorado River north of Blythe.
Jebel Faya is an archaeological site and limestone hill or escarpment near Al Madam in the Emirate of Sharjah, the UAE, located about 50 km east of the city of Sharjah, and between the shoreline of the Gulf and Al Hajar Mountains. It contains tool assemblages from the Paleolithic, Neolithic, Iron Age, and Bronze Age. Because its deepest assemblage has been dated to 125,000 years ago, it was thought to be the world's most ancient settlement yet discovered of anatomically modern humans outside of Africa at the time of its discovery in 2011. Finds of a yet earlier date have since been found at Misliya cave in the Levant.
Tuyajto Lake is a salt lake located in the Antofagasta Region, northern Chile. Located at an elevation of about 4,010 metres (13,160 ft), its surface area presently fluctuates between 1.7–2.7 square kilometres (0.66–1.04 sq mi) but in the past it was considerably larger; this led to humans going to the lake and creating archeological sites there. Presently, the lake is groundwater-fed and has no surface outlet but water might seep out underground. It is part of the Los Flamencos Natural Reserve.
Lake Tauca is a former lake in the Altiplano of Bolivia. It is also known as Lake Pocoyu for its constituent lakes: Lake Poopó, Salar de Coipasa and Salar de Uyuni. The lake covered large parts of the southern Altiplano between the Eastern Cordillera and the Western Cordillera, covering an estimated 48,000 to 80,000 square kilometres of the basins of present-day Lake Poopó and the Salars of Uyuni, Coipasa and adjacent basins. Water levels varied, possibly reaching 3,800 metres (12,500 ft) in altitude. The lake was saline. The lake received water from Lake Titicaca, but whether this contributed most of Tauca's water or only a small amount is controversial; the quantity was sufficient to influence the local climate and depress the underlying terrain with its weight. Diatoms, plants and animals developed in the lake, sometimes forming reef knolls.
Kurile Lake is a caldera and crater lake in Kamchatka, Russia. It is also known as Kurilskoye Lake or Kuril Lake. It is part of the Eastern Volcanic Zone of Kamchatka which, together with the Sredinny Range, forms one of the volcanic belts of Kamchatka. These volcanoes form from the subduction of the Pacific Plate beneath the Okhotsk Plate and the Asian Plate.
Longgang is a volcanic field in Jilin Province, China. It is also known as Chingyu, Longwan Group or Lung-wan Group. This volcanic field contains over 164 individual centres in the form of crater lakes, maars and volcanic cones and covers a surface area of 1,700 square kilometres (660 sq mi). The field is forested and mostly undisturbed by human activities.
Monte Burney is a volcano in southern Chile, part of its Austral Volcanic Zone which consists of six volcanoes with activity during the Quaternary. This volcanism is linked to the subduction of the Antarctic Plate beneath the South America Plate and the Scotia Plate.
Lake Tengger is a paleolake in China. It formed within the Tengger Desert during the Pleistocene and in reduced form during the Holocene as well. It is not certain when it existed.
Laguna Miscanti is a brackish water lake located in the altiplano of the Antofagasta Region in northern Chile. Cerro Miñiques volcano and Cerro Miscanti tower over this lake. This 13.5 square kilometres (5.2 sq mi) large heart-shaped lake has a deep blue colour and developed in a basin formed by a fault. South of Miscanti lies Laguna Miñiques, another lake which is separated from Miscanti by a lava flow that was emplaced there during the Pleistocene.
The geology of Saudi Arabia includes Precambrian igneous and metamorphic basement rocks, exposed across much of the country. Thick sedimentary sequences from the Phanerozoic dominate much of the country's surface and host oil.
Laguna del Negro Francisco is a lake in the Atacama Region of Chile and the southernmost closed lake in the country. It is situated 200 kilometres (120 mi) northeast of the city of Copiapó. The lake is about 10 kilometres (6.2 mi) long and 4 kilometres (2.5 mi) wide with a surface area of about 20.7 square kilometres (8.0 sq mi) and a depth of about 1 metre. A peninsula, probably formed by a moraine and subsequently modified by wind-driven accumulation of sand, separates the lake into a north-northwesterly and a south-southeasterly half with different colour and water composition.
Salar de Punta Negra is a saltpan in the Antofagasta Region of Chile with a surface area of about 230 square kilometres (89 sq mi). It is surrounded by deposits left by dry valleys that descend the Western Cordillera. These dry valleys, from mountains such as the Llullaillaco volcano, carry water only occasionally. More permanent sources of water, in the form of springs, also exist at Salar de Punta Negra.
The African humid period is a climate period in Africa during the late Pleistocene and Holocene geologic epochs, when northern Africa was wetter than today. The covering of much of the Sahara desert by grasses, trees and lakes was caused by changes in the Earth's axial tilt; changes in vegetation and dust in the Sahara which strengthened the African monsoon; and increased greenhouse gases. During the preceding Last Glacial Maximum, the Sahara contained extensive dune fields and was mostly uninhabited. It was much larger than today, and its lakes and rivers such as Lake Victoria and the White Nile were either dry or at low levels. The humid period began about 14,600–14,500 years ago at the end of Heinrich event 1, simultaneously to the Bølling–Allerød warming. Rivers and lakes such as Lake Chad formed or expanded, glaciers grew on Mount Kilimanjaro and the Sahara retreated. Two major dry fluctuations occurred; during the Younger Dryas and the short 8.2 kiloyear event. The African humid period ended 6,000–5,000 years ago during the Piora Oscillation cold period. While some evidence points to an end 5,500 years ago, in the Sahel, Arabia and East Africa, the end of the period appears to have taken place in several steps, such as the 4.2-kiloyear event.
The Quelccaya Ice Cap is the second largest glaciated area in the tropics, after Coropuna. Located in the Cordillera Oriental section of the Andes mountains in Peru, the cap covers an area of 42.8 square kilometres (16.5 sq mi) with ice up to 200 metres (660 ft) thick. It is surrounded by tall ice cliffs and a number of outlet glaciers, the largest of which is known as Qori Kalis Glacier; lakes, moraines, peat bogs and wetlands are also present. There is a rich flora and fauna, including birds that nest on the ice cap. Quelccaya is an important source of water, eventually melting and flowing into the Inambari and Vilcanota Rivers.
Espenberg is a volcanic field in Alaska that contains the largest maars on Earth. It was active during the Pleistocene until 17,500 years BP, when a large eruption formed the 8 by 6 kilometres wide Devil Mountain Maar and deposited tephra over 2,500 square kilometres (970 sq mi), burying vegetation and forming the largest maar on Earth. Other maars in the field are the North and South Killeak Maars and Whitefish Maar, and Devil Mountain is a shield volcano.
The Sokoch is a river in the western Kamchatka Peninsula, Russia, a right tributary of the Plotnikova.
The Rub' al Khali Basin or ar-Rubʻ al-Khālī / ar-rubʿ al-ḵālī Basin, Arabic for "Empty Quarter Basin", is a major endorheic sedimentary basin of approximately 560,000 square kilometres (220,000 sq mi) in southern Saudi Arabia, northeastern Yemen, southeastern Oman and southeasternmost United Arab Emirates. The onshore foreland on Mesozoic rift basin is geographically defined by the eponymous Rub' al Khali and covers the regions of Najran and Riyadh and the Eastern Province. The basin is geologically bound by the Central Arabian Arch in the north, the Oman Thrust in the east, the Northern Hadramaut Arch in the south, and the Arabian Shield in the west. Politically, the southwestern boundary is formed by the border with Yemen and the border with Oman forms the southeastern boundary.
Lake San Agustín is a former lake in New Mexico, which developed as a pluvial lake in the Plains of San Agustín during Pleistocene glacial periods. During its highstands it covered an area of 1,200 square kilometres (460 sq mi) with a maximum depth of 70 metres (230 ft), and split into several separate lakes while drying out. The lake last appeared during the last glacial maximum (LGM) and dried out at the beginning of the Holocene, with the last remnant disappearing about 5,000 years ago.
Desert kites are dry stone wall structures found in Southwest Asia, which were first discovered from the air during the 1920s. There are over 6,000 known desert kites, with sizes ranging from less than a hundred metres to several kilometres. They typically have a kite shape formed by two convergent "antennae" that run towards an enclosure, all formed by walls of dry stone less than one metre high, but variations exist.
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