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48-714: The Al Jaghbub Oasis is located on the northern edge of the Libyan Desert in a deep depression that is sunk about 10 m (33 ft) below sea level. To the north of the oasis are escarpments where the Al Jaghbub Formation dating to the Middle Miocene is exposed. This forms a layer largely composed of dolomite , running to the west where it is equivalent to the Marmarica Foundation and about 180 m (600 ft) thick, and to

96-410: A textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass. The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non- tropical coastal settings is silica (silicon dioxide, or SiO 2 ), usually in the form of quartz . Calcium carbonate

144-434: A diameter of between 0.074 and 4.75 millimeters. By another definition, in terms of particle size as used by geologists , sand particles range in diameter from 0.0625 mm (or 1 ⁄ 16  mm) a volume of approximately 0.00012 cubic millimetres, to 2 mm, a volume of approximately 4.2 cubic millimetres, the difference in volumes being 34,688 measures difference. Any particle falling within this range of sizes

192-434: A documentary called " Sand Wars " about the impact of the lack of construction sand. It shows the ecological and economic effects of both legal and illegal trade in construction sand. To retrieve the sand, the method of hydraulic dredging is used. This works by pumping the top few meters of sand out of the water and filling it into a boat, which is then transported back to land for processing. All marine life mixed in with

240-610: A high olivine content. Many sands, especially those found extensively in Southern Europe , have iron impurities within the quartz crystals of the sand, giving a deep yellow color. Sand deposits in some areas contain garnets and other resistant minerals, including some small gemstones . Rocks erode or weather over a long period of time, mainly by water and wind, and their sediments are transported downstream. These sediments continue to break apart into smaller pieces until they become fine grains of sand. The type of rock

288-534: A marine bivalve mollusc. Libyan Desert 24°N 25°E  /  24°N 25°E  / 24; 25 The Libyan Desert (not to be confused with the Libyan Sahara) is a geographical region filling the northeastern Sahara Desert , from eastern Libya to the Western Desert of Egypt and far northwestern Sudan. On medieval maps, its use predates today's Sahara , and parts of

336-604: A meteorite impact, marked by the Kebira crater , on the Libya-Egypt border. A specimen of the desert glass was used in a piece of Tutankhamun 's ancient jewellery. The Libyan Desert is barely populated apart from the modern settlements at oases of the lower Cyrenaica region in southeastern Libya. The indigenous population are Bisharin tribe , Mahas , and Berber . Where the desert extends into Egypt and no longer in Libya, it

384-489: A result. People sometimes dig holes in the sand at beaches for recreational purposes, but if too deep they can result in serious injury or death in the event of a collapse. Manufactured sand (M sand) is sand made from rock by artificial processes, usually for construction purposes in cement or concrete. It differs from river sand by being more angular, and has somewhat different properties. In Dubai , United Arab Emirates , sand needed to construct infrastructure and create

432-483: A significant dredging industry, raising environmental concerns over fish depletion, landslides, and flooding. Countries such as China, Indonesia, Malaysia, and Cambodia ban sand exports, citing these issues as a major factor. It is estimated that the annual consumption of sand and gravel is 40 billion tons and sand is a US$ 70 billion global industry. With increasing use, more is expected to come from recycling and alternatives to sand. The global demand for sand in 2017

480-696: A striking diversity of landscapes including mountains, oases, and sand seas. To the south lie the main mountain ranges, from the Jebel Uweinat (1,980 m or 6,500 feet), on the Libya-Egypt-Sudan border, the Tibesti to the south, on the border with Chad, and the Acacus to the southwest. The main oases are Jaghbub and Jalo in east, in Cyrenaica, Kufra in the southeast, and Murzuk in

528-508: Is called grus in geology or sharp sand in the building trade where it is preferred for concrete, and in gardening where it is used as a soil amendment to loosen clay soils. Sand that is transported long distances by water or wind will be rounded, with characteristic abrasion patterns on the grain surface. Desert sand is typically rounded. People who collect sand as a hobby are known as arenophiles . Organisms that thrive in sandy environments are psammophiles. Only some sands are suitable for

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576-574: Is found in places such as White Sands National Park and Salt Plains National Wildlife Refuge in the U.S. Sand is a non-renewable resource over human timescales, and sand suitable for making concrete is in high demand. Desert sand, although plentiful, is not suitable for concrete. Fifty billion tons of beach sand and fossil sand are used each year for construction. The exact definition of sand varies. The scientific Unified Soil Classification System used in engineering and geology corresponds to US Standard Sieves, and defines sand as particles with

624-853: Is generally known as the " Western Desert ". The term "Western Desert" contrasts with the Eastern Desert to the east of the Nile River , which lies between the Nile and the Red Sea . The Libyan desert is said to be one of the least hospitable regions on Earth. Its climate is surprisingly variable, being hot in summer, with average daytime temperatures of 50 °C (122 °F) and above, though this drops rapidly at night. In winter, days are cool, with temperatures averaging 27 °C (81 °F), but at night this can drop below freezing, with temperatures of −9 °C (16 °F) recorded. At these times

672-433: Is termed a sand grain . Sand grains are between gravel (with particles ranging from 2 mm up to 64 mm by the latter system, and from 4.75 mm up to 75 mm in the former) and silt (particles smaller than 0.0625 mm down to 0.004 mm). The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under

720-474: Is the most common mineral resistant to weathering . The composition of mineral sand is highly variable, depending on the local rock sources and conditions. The bright white sands found in tropical and subtropical coastal settings are eroded limestone and may contain coral and shell fragments in addition to other organic or organically derived fragmental material, suggesting that sand formation depends on living organisms, too. The gypsum sand dunes of

768-494: Is the second most common type of sand. One such example of this is aragonite , which has been created over the past 500   million years by various forms of life, such as coral and shellfish . It is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, as in the Caribbean . Somewhat more rarely, sand may be composed of calcium sulfate , such as gypsum and selenite , as

816-738: The Albert Atterberg standard in use during the early 20th century. The grains of sand in Archimedes ' The Sand Reckoner written around 240 BCE, were 0.02 mm in diameter. A 1938 specification of the United States Department of Agriculture was 0.05 mm. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. Sand feels gritty when rubbed between

864-563: The Idehan Ubari , bordering Algeria. The sand seas contain dunes up to 512 m (1,680 feet) in height, and cover approximately one quarter of the total desert region. Other features are the Aswad al Haruj (the "Black Desert"), a large circular region of black volcanic shield in the centre of the country, and the Hamada al Hamra  [ de ] (the "Red Desert") a rocky plateau to

912-924: The Italo-Turkish War of 1911–12, the desert became the scene of a two-decade struggle between the Italians and the Senussi starting from 1915, who were centred on the Jebel Akhdar in Cyrenaica and on the Kufra oasis. It ended in 1931 with the conquest of Kufra by the Italians. During the 1930s the Libyan desert was the scene of exploration and mapping by the Italian Army and Air Force. Others, such as Ralph Bagnold and László Almásy also travelled in south-eastern Libya and southern Egypt, searching for

960-514: The Krumbein phi scale , where size is Φ = -log 2 D; D being the particle size in mm. On this scale, for sand the value of Φ varies from −1 to +4, with the divisions between sub-categories at whole numbers. The most common constituent of sand, in inland continental settings and non-tropical coastal settings, is silica (silicon dioxide, or SiO 2 ), usually in the form of quartz , which, because of its chemical inertness and considerable hardness,

1008-772: The Western Desert Campaign . The deep desert saw operations by the Italian Auto-Saharan Companies , in combat with the Allied Long Range Desert Group (LRDG) and the Free French Régiment de Tirailleurs Sénégalais du Tchad (RTST). Other actions included the Siege of Giarabub (now Jaghbub), the battle of Kufra and the raid on Murzuk , all in 1941. The Calanshio Sand Sea is the site of

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1056-687: The White Sands National Park in New Mexico are famous for their bright, white color. Arkose is a sand or sandstone with considerable feldspar content, derived from weathering and erosion of a (usually nearby) granitic rock outcrop. Some sands contain magnetite , chlorite , glauconite , or gypsum . Sands rich in magnetite are dark to black in color, as are sands derived from volcanic basalts and obsidian . Chlorite - glauconite bearing sands are typically green in color, as are sands derived from basaltic lava with

1104-408: The endorheic region, with no rivers draining into or out of the desert. The Gilf Kebir plateau reaches an altitude of just over 1,000 m (3,300 feet), and along with the nearby massif of Jebel Uweinat is an exception to the uninterrupted territory of basement rocks covered by layers of horizontally bedded sediments, forming a massive sand plain, low plateaus, and dunes. The desert features

1152-636: The Libyan Desert include the Sahara's most arid and least populated regions; this is chiefly what sets the Libyan Desert apart from the greater Sahara. The consequent absence of grazing, and near absence of waterholes or wells needed to sustain camel caravans, prevented Trans-Saharan trade between Kharga (the Darb al Arbein) close to the Nile, and Murzuk in the Libyan Fezzan . This obscurity saw

1200-434: The Sahara is sand dunes, while 70% is bare rock. The wind is responsible for creating these different environments and shaping the sand to be round and smooth. These properties make desert sand unusable for construction. Beach sand is also formed by erosion. Over thousands of years, rocks are eroded near the shoreline from the constant motion of waves and the sediments build up. Weathering and river deposition also accelerate

1248-441: The construction industry, for example for making concrete . Grains of desert sand are rounded by being blown in the wind, and for this reason do not produce solid concrete, unlike the rough sand from the sea. Because of the growth of population and of cities and the consequent construction activity there is a huge demand for these special kinds of sand, and natural sources are running low. In 2012 French director Denis Delestrac made

1296-474: The east as far as the Moghra Oasis where it is only 5 m (16 ft) thick and has a high sand content. At Al Jaghbub it is about 120 m (400 ft) thick and consists of white to yellow limestone, clay, marl and sandstone. Fossils of echinoderms , bivalve molluscs , gastropods and bryozoans are found in this formation. The Siwa Oasis in western Egypt lies about 100 km (62 mi) to

1344-438: The extracted sand is killed and the ecosystem can continue to suffer for years after the mining is complete. Not only does this affect marine life, but also the local fishing industries because of the loss of life, and communities living close to the water's edge. When sand is taken out of the water it increases the risk of landslides, which can lead to loss of agricultural land and/or damage to dwellings. Sand's many uses require

1392-660: The fingers. Silt , by comparison, feels like flour . ISO 14688 grades sands as fine, medium, and coarse with ranges 0.063 mm to 0.2 mm to 0.63 mm to 2.0 mm. In the United States, sand is commonly divided into five sub-categories based on size: very fine sand ( 1 ⁄ 16 – 1 ⁄ 8  mm diameter), fine sand ( 1 ⁄ 8  mm – 1 ⁄ 4  mm), medium sand ( 1 ⁄ 4  mm – 1 ⁄ 2  mm), coarse sand ( 1 ⁄ 2  mm – 1 mm), and very coarse sand (1 mm – 2 mm). These sizes are based on

1440-475: The formation of hoar frost is not uncommon, and they are known as "White Nights". In the north, along the Mediterranean shore, cool onshore winds blow inland, while further south, hot, dry winds, known as Ghibli , blow from the interior, creating blinding sand-storms. Periodic droughts are common in the desert, often lasting several years. Historically, "Libya" referred to an ill-defined area to

1488-711: The lost oasis of Zerzura . Bagnold also travelled into northern Chad, to the Mourdi Depression , recording his findings in his book Libyan Sands: Travel in a Dead World , which was published in 1935. During the Second World War the north-eastern desert between El Agheila and the Egyptian border was the scene of heavy fighting between the Axis powers and the Western Allies , a period known as

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1536-485: The meaning has come to revert to the definition given above. The Libyan Desert covers an area of approximately 1,300,000 km (500,000 square miles), and extends approximately 1,100 km (680 miles) from east to west, and 1,000 km from north to south, in about the shape of a rectangle slanting to the south-east. Like most of the Sahara, this desert is primarily sand and hamada or stony plain. Sand plains, dunes , ridges, and some depressions (basins) typify

1584-418: The missing World War II aircraft Lady Be Good . The wreck was discovered 200 km (120 mi) north of Kufra 15 years after it was reported missing in 1943. Sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt . Sand can also refer to

1632-437: The process of creating a beach, along with marine animals interacting with rocks, such as eating the algae off of them. Once there is a sufficient amount of sand, the beach acts as a barrier to keep the land from eroding any further. This sand is ideal for construction as it is angular and of various sizes. Marine sand (or ocean sand) comes from sediments transported into the ocean and the erosion of ocean rocks. The thickness of

1680-461: The rate the sand can replenish, making it a non-renewable resource. Sand dunes are a consequence of dry conditions or wind deposition. The Sahara Desert is very dry because of its geographic location and proximity to the equator . It is known for its vast sand dunes, which exist mainly due to a lack of vegetation and water. Over time, wind blows away fine particles, such as clay and dead organic matter, leaving only sand and larger rocks. Only 15% of

1728-433: The region overlooked by early European explorers, and it was not until the early 20th century and the advent of the motor car before the Libyan Desert started to be fully explored. The term Libyan Desert began to appear widely on European maps in the last decades of the 19th century, typically identified as straddling the borders of present-day Egypt and Libya. This name derived from a territory known as Ancient Libya . (It

1776-460: The sand because they do not have as much time to dissolve away. The term for sand formed by weathering is "epiclastic." Sand from rivers are collected either from the river itself or its flood plain and accounts for the majority of the sand used in the construction industry. Because of this, many small rivers have been depleted, causing environmental concern and economic losses to adjacent land. The rate of sand mining in such areas greatly outweighs

1824-480: The sand layer varies, however it is common to have more sand closer to land; this type of sand is ideal for construction and is a very valuable commodity. Europe is the main miners of marine sand, which greatly hurts ecosystems and local fisheries. The study of individual grains can reveal much historical information as to the origin and kind of transport of the grain. Quartz sand that is recently weathered from granite or gneiss quartz crystals will be angular. It

1872-411: The sediment originated from and the intensity of the environment give different compositions of sand. The most common rock to form sand is granite , where the feldspar minerals dissolve faster than the quartz , causing the rock to break apart into small pieces. In high energy environments rocks break apart much faster than in more calm settings. In granite rocks this results in more feldspar minerals in

1920-754: The south, in Fezzan. The sand seas lie in a ring around the border of Libya. To the east lies the Calanshio Sand Sea , the western lobe of the Great Sand Sea straddling the Libya-Egypt border, and stretches 800 km (500 miles) from Jaghbub and Jalo in the north to Kufra in the south. To the south-east lies the Rebiana Sand Sea , near the border with Sudan. To the south west is the Idehan Murzuq , bordering Chad, and to west lies

1968-564: The southeast in a similar depression. The Al Jaghbub Oasis was an important staging post for trans-Saharan traders and for pilgrims going to Siwa, Cairo and on to Mecca . In 1856, Muhammad ibn Ali as-Senussi moved the headquarters of the Senussi movement from Bayda to here. Al Jaghbub became a fortress town with an important Islamic university, second only in prestige to the Al-Azhar University in Cairo. The protected area

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2016-493: The user to wear respiratory protection to avoid breathing the resulting fine silica dust . Safety data sheets for silica sand state that "excessive inhalation of crystalline silica is a serious health concern." In areas of high pore water pressure , sand and salt water can form quicksand , which is a colloid hydrogel that behaves like a liquid. Quicksand produces a considerable barrier to escape for creatures caught within, who often die from exposure (not from submersion) as

2064-575: The west of Ancient Egypt , whose boundary traditionally was the lake of Mareotis , outside Alexandria . The ancient Greeks, such as Herodotus , regarded the whole of the North African littoral, to Cape Spartel in Morocco , as "Libya". Later, the Romans organized the region the provinces of Libya Inferior and Libya Superior , which covered western Egypt and Cyrenaica. Thus the "Libyan Desert"

2112-594: The west, on the Tunisian border, coloured by iron oxide deposits. To the southeast, between Kufra and the Libya-Egypt-Sudan border, lies the Jebel Arkenu , with the associated Arkenu structures , thought to be caused by meteorite strikes. North of the Gilf Kebir plateau, among the shallow peripheral dunes of the southern Great Sand Sea , is a field of Libyan desert glass . This is thought to be associated with

2160-635: Was 9.55 billion tons as part of a $ 99.5 billion industry. In April 2022, the United Nations Environment Programme (UNEP) published a report stating that 50 billion tons of sand and gravel were being used every year. The report made 10 recommendations, including a ban on beach extraction, to avert a crisis, and move toward a circular economy for the two resources. While sand is generally non-toxic, sand-using activities such as sandblasting require precautions. Bags of silica sand used for sandblasting now carry labels warning

2208-566: Was not until 1934 that former Ottoman Tripolitania became known as Libya .) In his book Libyan Sands , Ralph Bagnold went as far as to suggest that the Libyan Desert was a separate geographical entity from the Sahara, cut off by the mountains and plateaus of the Ennedi and Tibesti in northern Chad, and the Akakus and Tassili n'Ajjer along the Algerian border in the west. Since that time

2256-513: Was set up to provide a habitat in which the native wild animals and plants of the area could flourish. The governmental body overseeing the protected area is the Technical Committee of Wildlife and National Parks which was created in 1990. The oasis is visited by birds, especially waterfowl, during their annual migrations. It is of particular interest because of the presence here of a subspecies of cockle Cardium edule rectidens ,

2304-624: Was the desert to the south of Ancient Libya . With the organization of the Italian colony of Libya in the 20th century the term "Libyan Desert" for this region became a misnomer, and the area of desert within Egypt became known as the " Western Desert " (i.e. west of the Nile, in contradistinction to the Eastern Desert, east of the Nile). Following the conquest of the territory by Italy during

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