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Ad-Dahna Desert
Ad-Dahna Desert is the central division of the Arabian Desert. It is a corridor of sandy terrain forming a bow-like shape that connects an-Nafud desert in the north to Rub' al-Khali desert in the south. Its length is more than siding Twaik Mountains from the east and does not exceed in width. It is also considered the geographical margin separating Al-Ahsa Province from Najd. Al-Dahna Desert is therefore the string that connects the great deserts of Saudi Arabia. The desert is a series of seven successive deserts, separated from one another by plains. Roads pass through Al-Dahnā, linking Kuwait with Al-Zilfī and Riyadh and connecting Riyadh with Hasa. Ad-Dahna desert is formed of high sand dunes spreading horizontally which are called veins (), mostly red in color since it contains Iron Oxides. Caves Beneath the harsh deserts of Saudi Arabia lie dark chambers and complex mazes filled with crystalline structures, stalactites and stalagmites. The limestone floor of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Oxide
An iron oxide is a chemical compound composed of iron and oxygen. Several iron oxides are recognized. Often they are non-stoichiometric. Ferric oxyhydroxides are a related class of compounds, perhaps the best known of which is rust. Iron oxides and oxyhydroxides are widespread in nature and play an important role in many geological and biological processes. They are used as iron ores, pigments, catalysts, and in thermite, and occur in hemoglobin. Iron oxides are inexpensive and durable pigments in paints, coatings and colored concretes. Colors commonly available are in the " earthy" end of the yellow/orange/red/brown/black range. When used as a food coloring, it has E number E172. Stoichiometries Iron oxides feature as ferrous ( Fe(II)) or ferric ( Fe(III)) or both. They adopt octahedral or tetrahedral coordination geometry. Only a few oxides are significant at the earth's surface, particularly wüstite, magnetite, and hematite. * Oxides of FeII ** FeO: ir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deserts Of Saudi Arabia
A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or "cold deserts". Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location. Deserts are formed by weathering processes as large variations in temperature between day and night strain the rocks, which consequently break in pieces. Although rain seldom occurs in deserts, there are occasional downpours that can result in flash floods. Rain falling on hot rocks can cause them to shatter, and the resulting fragments and rubble strewn over the desert floor are further e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Towns In Saudi Arabia
Thirteen ancient towns have been discovered in Saudi Arabia up to the present day. These include Qaryat al-Fāw, the Al-Ukhdūd archeological area, Hegra (Madā'in Ṣālih), Jubbah, Tārūt, Al-Shuwayḥaṭiyah, Thāj, Taimaa and Dūmat Al-Jandal. There are still more ancient towns in Saudi Arabia, but little information is currently available on them. Saudi Arabia occupies a unique and distinctive geographic location, bridging civilizations between continents. In ancient times the Arabian peninsula served as a corridor for trade; therefore it saw the beginning of many civilizations, the relics of which are still evident today. The Saudi government has recently established the Saudi Commission for Tourism and Antiquities, which is responsible for the preservation of these cities. Qaryat al-Fāw Qaryat al-Fāw (Arabic: قرية الفاو) also appears in the southern text as Qaryat Dhu Kahl (in association with the god Kahl), Qaryat al-Hamraa and Dhat al-Jnan. The name deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabian Desert
The Arabian Desert () is a vast desert wilderness in West Asia that occupies almost the entire Arabian Peninsula with an area of . It stretches from Yemen to the Persian Gulf and Oman to Jordan and Iraq. It is the fourth largest desert in the world and the largest in Asia. At its center is ''Ar-Rub' al-Khali'' (The Empty Quarter), one of the largest continuous bodies of sand in the world. It is an extension of the Sahara Desert. Gazelles, oryx, sand cats, and spiny-tailed lizards are just some of the desert-adapted species that survive in this extreme environment, which features everything from red dunes to deadly quicksand. The climate is mostly dry (the major part receives around of rain per year, but some very rare places receive as little as 50 mm), and temperatures oscillate between very high heat and seasonal night time freezes. It is part of the deserts and xeric shrublands biome and lie in biogeographical realms of the Palearctic (northern part) and Afrotro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rub' Al Khali
The Rub' al KhaliOther standardized transliterations include: /. The ' is the assimilated Arabic definite article, ', which can also be transliterated as '. (; , ) or Empty Quarter is a desert encompassing most of the southern third of the Arabian Peninsula. The desert covers some (the area of long. 44.5°−56.5°E, and lat. 16.5°−23.0°N), including parts of Saudi Arabia, Oman, the United Arab Emirates, and Yemen. It is part of the larger Arabian Desert. Description Terrain The desert is long, and wide. Its surface elevation varies from in the southwest to around sea level in the northeast. Most of the terrain is ergs, with sand dunes up to high, interspersed with gravel and gypsum plains. The sand is reddish-orange due to the presence of feldspar. There are also brackish salt flats in some areas, such as the Umm al Samim area on the desert's eastern edge. Ali Al-Naimi reports that the sand dunes do not drift. He goes on to say, Sand blows off the surface, of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saudi Geological Survey
The Saudi Geological Survey (SGS; ) is the national geological survey of the Kingdom of Saudi Arabia. History and profile The SGS was established as an independent entity attached to the ministry of petroleum and mineral resources following a council of ministers decision in 1999. It is built from other governmental agencies, including the former directorate general for mineral resources, the US Geological Survey (USGS) mission (1963–1999) and the Bureau de Recherches Géologiques et Minières (BRGM) mission (1972–1999). Activities The Saudi Geological Survey activities covers a broad range of strategic and applied earth science topics, with emphasis on understanding the geologic, economic, and engineering factors that affect sustainable management of mineral and groundwater resources, detection and mitigation of earthquakes and other geohazards, protection and management of the environment, and safe development of engineering and construction sites. The bulk of the wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedouin
The Bedouin, Beduin, or Bedu ( ; , singular ) are pastorally nomadic Arab tribes who have historically inhabited the desert regions in the Arabian Peninsula, North Africa, the Levant, and Mesopotamia (Iraq). The Bedouin originated in the Syrian Desert and Arabian Desert but spread across the rest of the Arab world in West Asia and North Africa after the spread of Islam. The English word ''bedouin'' comes from the Arabic ''badawī'', which means "desert-dweller", and is traditionally contrasted with ''ḥāḍir'', the term for sedentary people. Bedouin territory stretches from the vast deserts of North Africa to the rocky ones of the Middle East. They are sometimes traditionally divided into tribes, or clans (known in Arabic as ''ʿašāʾir''; or ''qabāʾil'' ), and historically share a common culture of herding camels, sheep and goats. The vast majority of Bedouins adhere to Islam, although there are some fewer numbers of Christian Bedouins present in the Fertile Cres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karst
Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some evidence that karst may occur in more weathering-resistant rocks such as quartzite given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. In regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of ''paleokarst'' (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's Oil and gas reserves and resource quantification, hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems. Etymology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stalagmites
A stalagmite (, ; ; ) is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typically composed of calcium carbonate, but may consist of lava, mud, peat, pitch, sand, sinter, and amberat (crystallized urine of pack rats). The corresponding formation hanging down from the ceiling of a cave is a stalactite. Formation and type Limestone stalagmites The most common stalagmites are speleothems, which usually form in limestone caves. Stalagmite formation occurs only under certain pH conditions within the cavern. They form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the chief form of calcium carbonate rock, which is dissolved by water that contains carbon dioxide, forming a calcium bicarbonate solution in caverns. The partial pressure of carbon dioxide in the water must be greater than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stalactites
A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite. Stalactites may be composed of lava, minerals, mud, peat, pitch, sand, sinter, and amberat (crystallized urine of pack rats). A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves. The corresponding formation on the floor of the cave is known as a stalagmite. Formation and type Limestone stalactites The most common stalactites are speleothems, which occur in limestone caves. They form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the chief form of calcium carbonate rock which is dissolved by water that con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crystalline
A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, consisting of flat faces with specific, characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification. The word ''crystal'' derives from the Ancient Greek word (), meaning both "ice" and " rock crystal", from (), "icy cold, frost". Examples of large crystals include snowflakes, diamonds, and table salt. Most inorganic solids are not crystals but polycrystals, i.e. many microscopic crystals fused together into a single solid. Polycrystals include most metals, rocks, ceramics, and ice. A third categor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
