1.
Halite
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Halite, commonly known as rock salt, is a type of salt, the mineral form of sodium chloride. The mineral is colorless or white, but may also be light blue, dark blue, purple, pink, red, orange, yellow or gray depending on the amount. It commonly occurs with other evaporite minerals such as several of the sulfates, halides. Halite occurs in vast beds of sedimentary evaporite minerals that result from the drying up of enclosed lakes, playas, salt beds may be hundreds of meters thick and underlie broad areas. In the United States and Canada extensive underground beds extend from the Appalachian basin of western New York through parts of Ontario, other deposits are in Ohio, Kansas, New Mexico, Nova Scotia and Saskatchewan. The Khewra salt mine is a deposit of halite near Islamabad. In the United Kingdom there are three mines, the largest of these is at Winsford in Cheshire producing on average a million tonnes per year. Salt domes are vertical diapirs or pipe-like masses of salt that have been squeezed up from underlying salt beds by mobilization due to the weight of overlying rock. Salt domes contain anhydrite, gypsum, and native sulfur, in addition to halite and sylvite and they are common along the Gulf coasts of Texas and Louisiana and are often associated with petroleum deposits. Germany, Spain, the Netherlands, Romania and Iran also have salt domes, salt glaciers exist in arid Iran where the salt has broken through the surface at high elevation and flows downhill. In all of these cases, halite is said to be behaving in the manner of a rheid, unusual, purple, fibrous vein filling halite is found in France and a few other localities. Halite crystals termed hopper crystals appear to be skeletons of the cubes, with the edges present and stairstep depressions on, or rather in. In a rapidly crystallizing environment, the edges of the cubes simply grow faster than the centers, halite crystals form very quickly in some rapidly evaporating lakes resulting in modern artifacts with a coating or encrustation of halite crystals. Halite flowers are rare stalactites of curling fibers of halite that are found in certain arid caves of Australias Nullarbor Plain, halite stalactites and encrustations are also reported in the Quincy native copper mine of Hancock, Michigan. Halite is often used both residentially and municipally for managing ice, because brine has a lower freezing point than pure water, putting salt or saltwater on ice that is near 0 °C will cause it to melt. It is common for homeowners in cold climates to spread salt on their sidewalks and driveways after a snow storm to melt the ice. It is not necessary to use so much salt that the ice is melted, rather. Also, many cities will spread a mixture of sand and salt on roads during, in addition to de-icing, rock salt is occasionally used in agriculture
2.
Dead Sea
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The Dead Sea, is a salt lake bordered by Jordan to the east and Israel and Palestine to the west. Its surface and shores are 430.5 metres below sea level, the Dead Sea is 304 m deep, the deepest hypersaline lake in the world. With 34. 2% salinity, it is 9.6 times as salty as the ocean and this salinity makes for a harsh environment in which plants and animals cannot flourish, hence its name. The Dead Sea is 50 kilometres long and 15 kilometres wide at its widest point and it lies in the Jordan Rift Valley and its main tributary is the Jordan River. The Dead Sea has attracted visitors from around the Mediterranean basin for thousands of years and it was one of the worlds first health resorts, and it has been the supplier of a wide variety of products, from asphalt for Egyptian mummification to potash for fertilizers. People also use the salt and the minerals from the Dead Sea to create cosmetics, the Dead Sea water has a density of 1.24 kg/litre, which makes swimming similar to floating. The Dead Sea is receding at an alarming rate, multiple canals and pipelines were proposed to reduce its recession, which had begun causing many problems. The Red Sea–Dead Sea Water Conveyance project, carried out by Jordan, will provide water to neighboring countries, the first phase of the project is scheduled to begin in 2018 and be completed in 2021. In Hebrew, the Dead Sea is Yām ha-Melaḥ, meaning sea of salt, the Bible uses this term alongside two others, the Sea of the Arabah, and the Eastern Sea. The designation Dead Sea never appears in the Bible, in prose sometimes the term Yām ha-Māvet is used, due to the scarcity of aquatic life there. In Arabic the Dead Sea is called al-Bahr al-Mayyit, or less commonly baḥrᵘ lūṭᵃ, another historic name in Arabic was the Sea of Zoʼar, after a nearby town in biblical times. The Greeks called it Lake Asphaltites, the Dead Sea is an endorheic lake located in the Jordan Rift Valley, a geographic feature formed by the Dead Sea Transform. This left lateral-moving transform fault lies along the plate boundary between the African Plate and the Arabian Plate. It runs between the East Anatolian Fault zone in Turkey and the end of the Red Sea Rift offshore of the southern tip of Sinai. It is here that the Upper Jordan River/Sea of Galilee/Lower Jordan River water system comes to an end. The Jordan River is the major water source flowing into the Dead Sea, although there are small perennial springs under and around the Dead Sea, forming pools. The Mujib River, biblical Arnon, is one the larger sources of the Dead Sea other than the Jordan. The Wadi Mujib valley,420 m below the sea level in the southern of Jordan valley, is a biosphere reserve, other more substantial sources are Wadi Darajeh /Nahal Dragot, and Nahal Arugot
3.
Mineral
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A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
4.
Sedimentary rock
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Sedimentary rocks are types of rock that are formed by the deposition and subsequent cementation of that material at the Earths surface and within bodies of water. Sedimentation is the name for processes that cause mineral and/or organic particles to settle in place. The particles that form a rock by accumulating are called sediment. Sedimentation may also occur as minerals precipitate from solution or shells of aquatic creatures settle out of suspension. The sedimentary rock cover of the continents of the Earths crust is extensive, sedimentary rocks are only a thin veneer over a crust consisting mainly of igneous and metamorphic rocks. Sedimentary rocks are deposited in layers as strata, forming a structure called bedding, sedimentary rocks are also important sources of natural resources like coal, fossil fuels, drinking water or ores. The study of the sequence of rock strata is the main source for an understanding of the Earths history, including palaeogeography, paleoclimatology. The scientific discipline that studies the properties and origin of rocks is called sedimentology. Sedimentology is part of both geology and physical geography and overlaps partly with other disciplines in the Earth sciences, such as pedology, geomorphology, geochemistry, sedimentary rocks have also been found on Mars. Clastic sedimentary rocks are composed of rock fragments that were cemented by silicate minerals. Clastic rocks are composed largely of quartz, feldspar, rock fragments, clay minerals, and mica, any type of mineral may be present, clastic sedimentary rocks, are subdivided according to the dominant particle size. Most geologists use the Udden-Wentworth grain size scale and divide unconsolidated sediment into three fractions, gravel, sand, and mud and this tripartite subdivision is mirrored by the broad categories of rudites, arenites, and lutites, respectively, in older literature. The subdivision of these three categories is based on differences in clast shape, conglomerates and breccias), composition. Conglomerates are dominantly composed of rounded gravel, while breccias are composed of dominantly angular gravel, composition of framework grains The relative abundance of sand-sized framework grains determines the first word in a sandstone name. Naming depends on the dominance of the three most abundant components quartz, feldspar, or the lithic fragments that originated from other rocks, all other minerals are considered accessories and not used in the naming of the rock, regardless of abundance. Clean sandstones with open space are called arenites. Muddy sandstones with abundant muddy matrix are called wackes, six sandstone names are possible using the descriptors for grain composition and the amount of matrix. Mudrocks are sedimentary rocks composed of at least 50% silt- and clay-sized particles and these relatively fine-grained particles are commonly transported by turbulent flow in water or air, and deposited as the flow calms and the particles settle out of suspension
5.
Crystallization
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Crystallization is the process where a solid forms where the atoms or molecules are highly organized in a structure known as a crystal. Some of the ways which crystals form are through precipitating from a solution, crystallization is also a chemical solid–liquid separation technique, in which mass transfer of a solute from the liquid solution to a pure solid crystalline phase occurs. In chemical engineering crystallization occurs in a crystallizer, crystallization is therefore related to precipitation, although the result is not amorphous or disordered, but a crystal. The crystallization process consists of two events, nucleation and crystal growth which are driven by thermodynamic properties as well as chemical properties. These stable clusters constitute the nuclei, therefore, the clusters need to reach a critical size in order to become stable nuclei. Such critical size is dictated by different factors. The crystal growth is the subsequent size increase of the nuclei that succeed in achieving the critical cluster size, crystal growth is a dynamic process occurring in equilibrium where solute molecules or atoms precipitate out of solution, and dissolve back into solution. Supersaturation is one of the forces of crystallization, as the solubility of a species is an equilibrium process quantified by Ksp. Depending upon the conditions, either nucleation or growth may be predominant over the other, many compounds have the ability to crystallize with some having different crystal structures, a phenomenon called polymorphism. Each polymorph is in fact a different thermodynamic solid state and crystal polymorphs of the compound exhibit different physical properties, such as dissolution rate, shape, melting point. For this reason, polymorphism is of importance in industrial manufacture of crystalline products. Additionally, crystal phases can sometimes be interconverted by varying factors such as temperature, there are many examples of natural process that involve crystallization. Geological time scale process examples include, Natural crystal formation, Stalactite/stalagmite, usual time scale process examples include, Snow flakes formation, Honey crystallization. Crystal formation can be divided into two types, where the first type of crystals are composed of a cation and anion, also known as a salt, the second type of crystals are composed of uncharged species, for example menthol. The formation of a solution does not guarantee crystal formation. A typical laboratory technique for crystal formation is to dissolve the solid in a solution in which it is partially soluble, the hot mixture is then filtered to remove any insoluble impurities. The filtrate is allowed to slowly cool, crystals that form are then filtered and washed with a solvent in which they are not soluble, but is miscible with the mother liquor. The process is repeated to increase the purity in a technique known as recrystallization
6.
Evaporation
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Evaporation is a type of vaporization of a liquid that occurs from the surface of a liquid into a gaseous phase that is not saturated with the evaporating substance. The other type of vaporization is boiling, which is characterized by bubbles of saturated vapor forming in the liquid phase, steam produced in a boiler is another example of evaporation occurring in a saturated vapor phase. Evaporation that occurs directly from the solid phase below the melting point, on average, a fraction of the molecules in a glass of water have enough heat energy to escape from the liquid. The water in the glass will be cooled by the evaporation until an equilibrium is reached where the air supplies the amount of heat removed by the evaporating water, in an enclosed environment the water would evaporate until the air is saturated. With sufficient temperature, the liquid would turn into vapor quickly, when the molecules collide, they transfer energy to each other in varying degrees, based on how they collide. Sometimes the transfer is so one-sided for a molecule near the surface that it ends up with energy to escape. Evaporation is an part of the water cycle. The sun drives evaporation of water from oceans, lakes, moisture in the soil, in hydrology, evaporation and transpiration are collectively termed evapotranspiration. Evaporation of water occurs when the surface of the liquid is exposed, allowing molecules to escape and form water vapor, when only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, as the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, and the temperature of the liquid decreases. This phenomenon is also called evaporative cooling and this is why evaporating sweat cools the human body. Evaporation also tends to proceed quickly with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure. For example, laundry on a line will dry more rapidly on a windy day than on a still day. Three key parts to evaporation are heat, atmospheric pressure, on a molecular level, there is no strict boundary between the liquid state and the vapor state. Instead, there is a Knudsen layer, where the phase is undetermined, because this layer is only a few molecules thick, at a macroscopic scale a clear phase transition interface cannot be seen. It is just that the process is slower and thus significantly less visible. If evaporation takes place in an area, the escaping molecules accumulate as a vapor above the liquid. Many of the return to the liquid, with returning molecules becoming more frequent as the density
7.
Arid
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A region is arid when it is characterized by a severe lack of available water, to the extent of hindering or preventing the growth and development of plant and animal life. Environments subject to arid climates tend to lack vegetation and are called xeric or desertic, most arid climates surround the equator, these places include most of Africa and parts of South America, Central America and Australia. The distribution of aridity observed at any one point in time is largely the result of the circulation of the atmosphere. The latter does change significantly over time through climate change, for example, temperature increase across the Nile Basin over the next 30–40 years could change the region from semi-arid to arid, resulting in a significant reduction in agricultural land. In addition, changes in use can result in greater demands on soil water. Durrenberger, R. W. Arid Climates, article in The Encyclopedia of Climatology, p. 92-101, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, ISBN 0-87933-009-0. J Aridity Indexes, article in The Encyclopedia of Climatology, p. 102-107, Edited by J. E. Oliver and R. W. Fairbridge, Van Nostrand Reinhold Company, New York, blue Peace for the Nile Report,2009, Strategic Foresight Group
8.
Carbonate
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In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, a polyatomic ion with the formula of CO2−3. The name may mean an ester of carbonic acid, an organic compound containing the carbonate group C2. In geology and mineralogy, the term carbonate can refer both to carbonate minerals and carbonate rock, and both are dominated by the ion, CO2−3. Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock, sodium carbonate and potassium carbonate have been used since antiquity for cleaning and preservation, as well as for the manufacture of glass. Carbonates are widely used in industry, e. g. in iron smelting, as a raw material for Portland cement and lime manufacture, in the composition of ceramic glazes, the carbonate ion is the simplest oxocarbon anion. It consists of one carbon atom surrounded by three oxygen atoms, in a planar arrangement, with D3h molecular symmetry. It has a mass of 60.01 g/mol and carries a total formal charge of −2. It is the base of the hydrogen carbonate ion, HCO−3. The Lewis structure of the ion has two single bonds to negative oxygen atoms, and one short double bond to a neutral oxygen. This structure is incompatible with the symmetry of the ion. This process is called calcination, after calx, the Latin name of quicklime or calcium oxide, CaO, exceptions include lithium, sodium, potassium and ammonium carbonates, as well as many uranium carbonates. In aqueous solution, carbonate, bicarbonate, carbon dioxide, in strongly basic conditions, the carbonate ion predominates, while in weakly basic conditions, the bicarbonate ion is prevalent. In more acid conditions, aqueous carbon dioxide, CO2, is the main form, thus sodium carbonate is basic, sodium bicarbonate is weakly basic, while carbon dioxide itself is a weak acid. Carbonated water is formed by dissolving CO2 in water under pressure, in living systems an enzyme, carbonic anhydrase, speeds the interconversion of CO2 and carbonic acid. Although the carbonate salts of most metals are insoluble in water, in solution this equilibrium between carbonate, bicarbonate, carbon dioxide and carbonic acid changes consonant to changing temperature and pressure conditions. In the case of ions with insoluble carbonates, e. g. CaCO3. This is an explanation for the buildup of scale inside pipes caused by hard water, in organic chemistry a carbonate can also refer to a functional group within a larger molecule that contains a carbon atom bound to three oxygen atoms, one of which is double bonded. These compounds are known as organocarbonates or carbonate esters, and have the general formula ROCOOR′
9.
Gypsum
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Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer, and as the constituent in many forms of plaster, blackboard chalk. Mohs scale of hardness, based on scratch Hardness comparison. It forms as a mineral and as a hydration product of anhydrite. The word gypsum is derived from the Greek word γύψος, plaster, because the quarries of the Montmartre district of Paris have long furnished burnt gypsum used for various purposes, this dehydrated gypsum became known as plaster of Paris. Upon addition of water, after a few tens of minutes plaster of Paris becomes regular gypsum again, causing the material to harden or set in ways that are useful for casting, Gypsum was known in Old English as spærstān, spear stone, referring to its crystalline projections. Gypsum may act as a source of sulfur for plant growth, which was discovered by J. M. Mayer, american farmers were so anxious to acquire it that a lively smuggling trade with Nova Scotia evolved, resulting in the so-called Plaster War of 1820. In the 19th century, it was known as lime sulfate or sulfate of lime. Gypsum is moderately water-soluble and, in contrast to most other salts, it exhibits retrograde solubility, when gypsum is heated in air it loses water and converts first to calcium sulfate hemihydrate, and, if heated further, to anhydrous calcium sulfate. As for anhydrite, its solubility in saline solutions and in brines is also dependent on NaCl concentration. Gypsum crystals are found to contain water and hydrogen bonding. Gypsum occurs in nature as flattened and often twinned crystals, and transparent, selenite contains no significant selenium, rather, both substances were named for the ancient Greek word for the Moon. Selenite may also occur in a silky, fibrous form, in case it is commonly called satin spar. Finally, it may also be granular or quite compact, in hand-sized samples, it can be anywhere from transparent to opaque. A very fine-grained white or lightly tinted variety of gypsum, called alabaster, is prized for ornamental work of various sorts, in arid areas, gypsum can occur in a flower-like form, typically opaque, with embedded sand grains called desert rose. It also forms some of the largest crystals found in nature, up to 12 m long, Gypsum is a common mineral, with thick and extensive evaporite beds in association with sedimentary rocks. Deposits are known to occur in strata from as far back as the Archaean eon, Gypsum is deposited from lake and sea water, as well as in hot springs, from volcanic vapors, and sulfate solutions in veins. Hydrothermal anhydrite in veins is commonly hydrated to gypsum by groundwater in near-surface exposures and it is often associated with the minerals halite and sulfur
10.
Calcite
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Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate. The Mohs scale of hardness, based on scratch hardness comparison. Other polymorphs of calcium carbonate are the minerals aragonite and vaterite, aragonite will change to calcite at 380–470 °C, and vaterite is even less stable. Calcite is derived from the German Calcit, a term coined in the 19th century from the Latin word for lime and it is thus etymologically related to chalk. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals, however, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, prisms, or various scalenohedra. Calcite exhibits several twinning types adding to the variety of observed forms and it may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form and its fracture is conchoidal, but difficult to obtain. It has a defining Mohs hardness of 3, a gravity of 2.71. Color is white or none, though shades of gray, red, orange, yellow, green, blue, violet, brown, calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. A transparent variety called Iceland spar is used for optical purposes, acute scalenohedral crystals are sometimes referred to as dogtooth spar while the rhombohedral form is sometimes referred to as nailhead spar. Single calcite crystals display an optical property called birefringence and this strong birefringence causes objects viewed through a clear piece of calcite to appear doubled. The birefringent effect was first described by the Danish scientist Rasmus Bartholin in 1669, at a wavelength of ~590 nm calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively. Between 190 and 1700 nm, the refractive index varies roughly between 1.9 and 1.5, while the extraordinary refractive index varies between 1.6 and 1.4. Calcite, like most carbonates, will dissolve with most forms of acid, calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Although calcite is fairly insoluble in water, acidity can cause dissolution of calcite. Ambient carbon dioxide, due to its acidity, has a slight solubilizing effect on calcite, calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. On a landscape scale, continued dissolution of calcium carbonate-rich rocks can lead to the expansion and eventual collapse of cave systems, high-grade optical calcite was used in World War II for gun sights, specifically in bomb sights and anti-aircraft weaponry
11.
Anhydrite
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Anhydrite is a mineral—anhydrous calcium sulfate, CaSO4. It is in the crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium and strontium sulfates, distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5 and the gravity is 2.9. The color is white, sometimes greyish, bluish, or purple, on the best developed of the three cleavages, the lustre is pearly, on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the commonly occurring gypsum. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C under normal atmospheric conditions, anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite, molybdenite, and pyrite in vein deposits. Anhydrite is most frequently found in deposits with gypsum, it was, for instance, first discovered, in 1794. In this occurrence, depth is critical since nearer the surface anhydrite has been altered to gypsum by absorption of circulating ground water and this is one of the several methods by which the mineral has been prepared artificially, and is identical with its mode of origin in nature. The mineral is common in salt basins, anhydrite occurs in a tidal flat environment in the Persian Gulf sabkhas as massive diagenetic replacement nodules. Cross sections of these nodular masses have an appearance and have been referred to as chicken-wire anhydrite. Nodular anhydrite occurs as replacement of gypsum in a variety of depositional environments. Massive amounts of anhydrite occur when salt domes form a caprock, anhydrite is 1–3% of the salt in salt domes and is generally left as a cap at the top of the salt when the halite is removed by pore waters. The typical cap rock is a salt, topped by a layer of anhydrite, topped by patches of gypsum, interaction with oil can reduce SO4 creating calcite, water, and hydrogen sulfide. Anhydrite has been found in igneous rocks, for example in the intrusive dioritic pluton of El Teniente, Chile and in trachyandesite pumice erupted by El Chichón volcano. The name anhydrite was given by A. G. Werner in 1804, because of the absence of water of crystallization, as contrasted with the presence of water in gypsum. Some obsolete names for the species are muriacite and karstenite, the former, the Catalyst Science Discovery Centre, Widnes, has a relief carving of an anhydrite kiln, made from a piece of anhydrite, for the United Sulphuric Acid Corporation
12.
Sylvite
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Sylvite, or sylvine, is potassium chloride in natural mineral form. It forms crystals in the system very similar to normal rock salt. The two are, in fact, isomorphous, Sylvite is colorless to white with shades of yellow and red due to inclusions. It has a Mohs hardness of 2.5 and a gravity of 1.99. It has a index of 1.4903. Sylvite has a salty taste with a distinct bitterness, Sylvite is one of the last evaporite minerals to precipitate out of solution. As such, it is found in very dry saline areas. Its principal use is as a potassium fertilizer, Sylvite is found in many evaporite deposits worldwide. Massive bedded deposits occur in New Mexico and western Texas, and in Utah in the US, the vast deposits in Saskatchewan, Canada were formed by the evaporation of a Devonian seaway. Sylvite is the mineral of Saskatchewan. Sylvite was first described in 1832 at Mt. Vesuvius near Napoli in Italy and named for the Dutch chemist, Sylvite, along with quartz, fluorite and halite, is used for spectroscopic prisms and lenses. Sylvinite Mineral Resources of Saskatchewan Chisholm, Hugh, ed. Sylvite
13.
Carnallite
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Carnallite is an evaporite mineral, a hydrated potassium magnesium chloride with formula KMgCl3·6. It is variably colored yellow to white, reddish, and sometimes colorless or blue and it is usually massive to fibrous with rare pseudohexagonal orthorhombic crystals. The mineral is deliquescent and specimens must be stored in an airtight container, Carnallite occurs with a sequence of potassium and magnesium evaporite minerals, sylvite, kainite, picromerite, polyhalite, and kieserite. Carnallite is an uncommon double chloride mineral that forms under specific environmental conditions in an evaporating sea or sedimentary basin. These deposits date from the Devonian through the Permian Periods, Carnallite was first described in 1856 from its type location of Stassfurt Deposit, Saxony-Anhalt, Germany. It was named for the Prussian mining engineer Rudolf von Carnall and they are composed of a halogen and a metal ion. The crystal chemistry of halides is characterized by the electronegativity of halogen ions and this means that the dominant large ions are the Cl−, Br−, F−, or I−. The ions combine with similarly large but low valence and weakly polarized cations, the cations are mostly of the alkali metal group. Sylvite is a compound with the formula KCl. Sylvite precipitates first from mixed solutions of K+, Mg2+ and Cl−, synthetic carnallite crystal specimens can be produced from 1.5 mole percent KCl and 98.5 mole percent MgCl2·6H2O by slow crystallization at 25 °C. Carnallite can also be produced by grinding the combination of hydrated magnesium chloride, there is a network of KCl6 octahedra, with two-thirds of them sharing faces. Mg6 octahedra occupy the spaces within the KCl octahedra. The interatomic distance between the Mg and the H2O ranges from 0.204 to 0.209 nm. with an average is 0.2045 nm. The interatomic distance between K and Cl ranges 0.317 to 0.331 nm. with an average of 0.324 nm, the resulting structure has a calculated density of 1.587 g/cm3, in good agreement with the measured value of 1.602 g/cm3. Face sharing creates more chance of instability, according to the third of Paulings rules, in carnallite, the water molecules enclose the magnesium ions. This prevents the magnesium and the chloride from interacting directly, instead, the five chloride anions are each coordinated to two potassium cations as well as four water molecules. This means that each chloride anion receives 1/6 of a +1 charge from each of the two potassium ions, the chloride also obtains 1/6 of a +1 charge from each the four water molecules. The charges thus total six 1/6 positive charges, which balance the charge of the chloride
14.
Polyhalite
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Polyhalite is an evaporite mineral, a hydrated sulfate of potassium, calcium and magnesium with formula, K2Ca2Mg4·2H2O. Polyhalite crystallizes in the system although crystals are very rare. The normal habit is massive to fibrous and it is typically colorless, white to gray, although it may be brick red due to iron oxide inclusions. It has a Mohs hardness of 3.5 and a gravity of 2.8. It occurs in marine evaporites and is a major potassium ore mineral in the Carlsbad Deposits of New Mexico. It is also present as a 2-3% contaminant of Himalayan salt, polyhalite was first described in 1818 for specimens from its type locality in Salzburg, Austria. Despite the similarity in names between it and halite, their connection is that both are evaporite minerals. The use of the Greek words for many and salt in polyhalite is due to polyhalite consisting of metals that can form salts in the more general sense of the word salt used in chemistry. The only polyhalite mined in the world comes from a layer of rock over 1,000 m below the North Sea off the North Yorkshire coast in the UK, deposited 260 million years ago, it lies 150–170 m below the potash seam at the Boulby Mine. Sirius Minerals Plc is developing a new mine in the area, in 2010, the first mining operations of the polyhalite mineral commenced at Boulby Mine. The mine is currently the producer of polyhalite which is marketed by Israel Chemicals Ltd as Polysulphate
15.
Kainite
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Kainite is an evaporite mineral in the class of Sulfates with additional anions, with H2O according to the Nickel-Strunz classification. It is a hydrated potassium-magnesium sulfate-chloride, naturally occurring in irregular granular masses or as coatings in cavities or fissures. This mineral is dull and soft, and is colored white, yellowish, grey, reddish and its name is derived from Greek καινος, as it was the first mineral discovered that contained both sulfate and chloride as anions. Kainite is of bitter taste and soluble in water, on recrystallization picromerite is deposited from the solution. Kainite was discovered in the Stassfurt salt mines in todays Saxony-Anhalt, kainite is a typical secondary mineral that forms through metamorphosis in marine deposits of potassium carbonate, and is also occasionally formed through resublimation from volcanic vapours. It is often accompanied by anhydrite, carnallite, halite, and it has also been identified in Gusev Crater on Mars. Kainite is used as a source of potassium and magnesium compounds, as a fertilizer, and as gritting salt
16.
Kieserite
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Kieserite is the magnesium sulfate mineral and is named after Dietrich Georg von Kieser. It has a vitreous luster and it is colorless, grayish-white or yellowish and its hardness is 3.5 and crystallizes in the monoclinic crystal system. Gunningite is the member of the kieserite group of minerals. Kieserite commonly occurs in marine evaporites and rarely in volcanic environments as a sublimate and it occurs in association with halite, carnallite, polyhalite, anhydrite, boracite, sulfoborite, leonite, epsomite and celestine. In early 2005, Mars Express, a European Space Agency orbiter, discovered evidence of kieserite in patches of Valles Marineris, along with gypsum and this is direct evidence of Marss watery past and augments similar discoveries made by the Mars Exploration Rover Opportunity in 2004. It is used in the production of Epsom salt and as a fertilizer, List of minerals List of minerals named after people
17.
Borax
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Soid Borax, also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important boron compound, a mineral, and a salt of boric acid. Powdered borax is white, consisting of colorless crystals that dissolve easily in water. Borax has a variety of uses. It is a component of many detergents, cosmetics, and enamel glazes, in artisanal gold mining, the borax method is sometimes used as a substitute for toxic mercury in the gold extraction process. Borax was reportedly used by miners in parts of the Philippines in the 1900s. The term borax is used for a number of closely related minerals or chemical compounds that differ in their water content. Commercially sold borax is partially dehydrated, Borax was first discovered in dry lake beds in Tibet and was imported via the Silk Road to the Arabian Peninsula in the 8th Century AD. However, it is formulated as Na2·8H2O, since borax contains the 2− ion. In this structure, there are two four-coordinate boron atoms and two boron atoms. Borax is also converted to boric acid and other borates. When borax is added to a flame, it produces a green color. Borax is not used for purpose in fireworks due to the overwhelming yellow color of sodium. Boric acid is used to color methanol flames a transparent green, the English word borax is Latinized, the Middle English form was boras, from Old French boras, bourras. That may have been from medieval Latin baurach, borac, borax, or maybe directly from the Arabic, along with Spanish borrax and Italian borrace, the Arabic was بورق bauraq/bwrk, a word also used for borax. Traditional Arabic dictionaries say that it derives from the verb to glisten, which is also written بورق bwrq, but it seems to actually derive from the Persian būrah. The word borax is found in Arabic būraq, meaning white, which is from Middle Persian bwrk, another name for borax is tincal, from Sanskrit. The word tincal /ˈtɪŋkəl/ tinkle, or tincar /ˈtɪŋkər/ tinker, refers to crude borax, before it is purified, as mined from deposits in Tibet, Persia. The word was adopted in the 17th century from Malay tingkal and from Urdu/Persian/Arabic تنکار tinkār/tankār and these all appear to be related to the Sanskrit टांकण ṭānkaṇa
18.
Epsomite
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Epsomite is a hydrous magnesium sulfate mineral with formula MgSO4·7H2O. Epsomite crystallizes in the system as rarely found acicular or fibrous crystals. It is colorless to white with tints of yellow, green, the Mohs hardness is 2 to 2.5 and it has a low specific gravity of 1.67. Epsomite is the same as the chemical, Epsom salt. It absorbs water from the air and converts to hexahydrate with the loss of one water molecule, epsomite forms as encrustations or efflorescences on limestone cavern walls and mine timbers and walls, rarely as volcanic fumarole deposits, and as rare beds in evaporite layers. It was first systematically described in 1806 for an occurrence near Epsom, Surrey, England and it occurs in association with melanterite, gypsum, halotrichite, pickeringite, alunogen, rozenite and mirabilite. The epsomite group includes solid solution series with morenosite and goslarite Kieserite is a hydrated magnesium sulfate
19.
Gaylussite
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Gaylussite is a carbonate mineral, a hydrated sodium calcium carbonate, formula Na2Ca2·5H2O. It occurs as translucent, vitreous white to grey to yellow monoclinic prismatic crystals and it is an unstable mineral which dehydrates in dry air and decomposes in water. It is formed as an evaporite from alkali lacustrine waters and it also occurs rarely as veinlets in alkalic igneous rocks. It was first described in 1826 for an occurrence in Lagunillas, Merida and it was named for French chemist Joseph Louis Gay-Lussac. The mineral has been reported from drill core in Lonar lake in Buldhana district, Maharashtra. Lonar lake was created by an impact during the Pleistocene Epoch
20.
Glauberite
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Glauberite is a monoclinic sodium calcium sulfate mineral with the formula Na2Ca2. It was first described in 1808 for material from the El Castellar Mine, Villarrubia de Santiago, Toledo, Castile-La Mancha and it was named for the extracted Glaubers salts after the German alchemist Johann Rudolf Glauber. It occurs associated with halite, polyhalite, anhydrite, gypsum, because of its solubility, glauberite is often dissolved away from the crystal matrix leaving a distinctly shaped hollow cast. Its mineral composition is readily altered into other minerals as pseudomorphs, gypsum pseudomorphs are common due to increased humidity
21.
Mirabilite
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Mirabilite, also known as Glaubers salt, is a hydrous sodium sulfate mineral with the chemical formula Na2SO4·10H2O. It is a vitreous, colorless to white monoclinic mineral that forms as an evaporite from sodium sulfate-bearing brines and it is found around saline springs and along saline playa lakes. Associated minerals include gypsum, halite, thenardite, trona, glauberite, Mirabilite is unstable and quickly dehydrates in dry air, the prismatic crystals turning into a white powder, thenardite. In turn, thenardite can also absorb water and converts to mirabilite, Mirabilite is used as a purgative in the Traditional Chinese medicine, in Mandarin, it is called máng xiāo. Its name is based on the phrase Sal mirabilis used by Johann Rudolph Glauber when he inadvertently synthesized mirabilite, maricopa. edu American Mineralogist Mirabilite as a tracer of past evolution of the Aral Sea
22.
Trona
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Trona is a non-marine evaporite mineral. It is mined as the source of sodium carbonate in the United States. The word trona entered English by way of either Swedish or Spanish, both of these derive from the Arabic trōn, which in turn derives from the Arabic natron, and Hebrew נטרן, which comes from ancient Greek νιτρον, derived ultimately from ancient Egyptian ntry. Trona is found at Owens Lake and Searles Lake, California, the Green River Formation of Wyoming and Utah, trona has also been mined at Lake Magadi in the Kenyan Rift Valley for nearly 100 years. The northern part of Lake Natron is covered by a 1.5 m thick trona bed, the Beypazari region in the Ankara Province of Turkey has some 33 trona beds in two fault-bound lensoid bodies in and above oil shales of the Lower Hirka Formation. Trona has also found in magmatic environments. The crystal structure of trona was first determined by Brown et al, the structure consists of units of 3 edge-sharing sodium polyhedra, cross-linked by carbonate groups and hydrogen bonds. Bacon and Curry refined the structure determination using two-dimensional single-crystal neutron diffraction, the dynamically disordered H atom was reinvestigated at low temperature by OBannon et al.2014 and they concluded that it does not order at temperatures as low as 100K. Trona is a source of soda ash, which is a significant economic commodity because of its applications in manufacturing glass, chemicals, paper, detergents. It is used to condition water and it is used to remove sulfur from both flue gases and lignite coals. It is a product of carbon sequestration of flue gases and it is also used as a food additive. Magadi Soda Company Searles Valley Minerals Inc, Solvay Tata Chemicals FMC Corporation General Chemical OCI Chemical Corp. American Natural Soda Ash Company Natron Nahcolite Shortite Sodium sesquicarbonate Thermonatrite
23.
Great Salt Lake
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The Great Salt Lake, located in the northern part of the U. S. state of Utah, is the largest salt water lake in the Western Hemisphere, and the eighth-largest terminal lake in the world. In an average year the lake covers an area of around 1,700 square miles, for instance, in 1963 it reached its lowest recorded size at 950 square miles, but in 1988 the surface area was at the historic high of 3,300 square miles. In terms of area, it is the largest lake in the United States that is not part of the Great Lakes region. The lake is the largest remnant of Lake Bonneville, a prehistoric lake that once covered much of western Utah. The three major tributaries to the lake, the Jordan, Weber, and Bear rivers together deposit around 1.1 million tons of minerals in the each year. As it is endorheic, it has very high salinity, far saltier than seawater, which makes swimming similar to floating and its shallow, warm waters cause frequent, sometimes heavy lake-effect snows from late fall through spring. The Great Salt Lake is a remnant of a larger prehistoric lake called Lake Bonneville. At its greatest extent, Lake Bonneville spanned 22,400 square miles, nearly as large as present-day Lake Michigan, and roughly ten times the area of the Great Salt Lake today. Bonneville reached 923 ft at its deepest point, and covered much of present-day Utah and small portions of Idaho, Lake Bonneville existed until about 16,800 years ago, when a large portion of the lake was released through the Red Rock Pass in Idaho. With the warming climate, the lake began to dry, leaving the Great Salt Lake, Utah Lake, Sevier Lake. While the lake was known by local Native Americans, it entered written history through the records of Silvestre Vélez de Escalante. No name was given to it at the time, and it was not shown on the map by Bernardo Miera y Pacheco, in 1824, it was observed, apparently independently, by Jim Bridger and Etienne Provost. Shortly thereafter other trappers saw it and walked around it, most of the trappers, however, were illiterate and did not record their discoveries. As oral reports of their findings made their way to those who did make records, Escalante had been on the shores of Utah Lake, which he named Laguna Timpanogos. It was the larger of the two lakes that appeared on Mieras map, other cartographers followed his lead and charted Lake Timpanogos as the largest lake in the region. As people came to know of the Great Salt Lake, they interpreted the maps to think that Timpanogos referred to the Great Salt Lake, on some maps the two names were used synonymously. In time Timpanogos was dropped from the maps and its association with Utah Lake was forgotten. Fremont led the first scientific expedition to the lake, but with winter coming on and that happened in 1850 under the leadership of Howard Stansbury
24.
Depositional environment
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In most cases the environments associated with particular rock types or associations of rock types can be matched to existing analogues. However, the back in geological time sediments were deposited. Sedimentary Environments, Processes, Facies and Stratigraphy, sedimentary Environments Classification Charts Depositional environments on e-notes
25.
Graben
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In geology, a graben is a depressed block of the Earths crust bordered by parallel faults. Graben is German for ditch or trench, the plural form is either graben or grabens. A graben is a valley with an escarpment on each side caused by the displacement of a block of land downward. Graben often occur side-by-side with horsts, horst and graben structures indicate tensional forces and crustal stretching. Graben are produced from parallel normal faults, where the displacement of the wall is downward. The faults typically dip toward the center of the graben from both sides, horsts are parallel blocks that remain between graben, the bounding faults of a horst typically dip away from the center line of the horst. Single or multiple graben can produce a rift valley, in many rifts, the graben are asymmetric, with a major fault along only one of the boundaries, and these are known as half-graben. The polarity of the bounding faults typically alternates along the length of the rift. The asymmetry of a half-graben strongly affects syntectonic deposition, comparatively little sediment enters the half-graben across the main bounding fault because of footwall uplift on the drainage systems. The exception is at any offset in the bounding fault. Most of the sediment will enter the half-graben down the hanging wall side. S. Central Graben, North Sea Viking Graben, North Sea Fossa
26.
Half-graben
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A half-graben is a geological structure bounded by a fault along one side of its boundaries, unlike a full graben where a depressed block of land is bordered by parallel faults. A rift is a region where the lithosphere extends as two parts of the Earths crust pull apart, often a rift will form in an area of the crust that is already weakened by earlier geological activity. Extensional faults form parallel to the axis of the rift, an extensional fault may be seen as a crack in the crust that extends down at an angle to the vertical. As the two sides pull apart, the wall will move downward relative to the footwall. The crust thins and sinks, forming a rift basin, warm mantle material wells up, melting the crust and often causing volcanoes to emerge in the rift basin. Extensional basins may appear to be caused by a graben, or depressed block of land, in fact, they are usually made of linked asymmetrical half-grabens. Faults with antithetic slope directions linked in to a fault, or periodic changes of dip in the controlling faults. As the rift expands, the rift flanks lift up due to compensation of the lithosphere. This creates the asymmetric topographic profile that is typical of half grabens, the half grabens may have alternating polarities along the rift axis, dividing the rift valley into segments. Often the extensional fault systems are segmented in these rifts, rift border faults with lengths over 10 kilometres are separated by relay ramp structures. The relay ramps may provide pathways for sediment to be carried into the basin, typically the rift is broken along its axis into segments about 50 to 150 kilometres long. Four zones of sedimentation can be defined in a half-graben, the first is escarpment margin sedimentation, found along the major border faults bounding the half graben, where the deepest part of the basin meets the highest rift-shoulder mountains. Comparatively little sediment enters the half-graben across the major bounding fault, rivers on that side therefore carry sediment away from the rift valley. But as the lowest part of the basin with the greatest rate of subsidence, the escarpment margin experiences the highest rates of sedimentation and this sedimentation often includes very coarse debris such as huge blocks from rock falls, as well as fans of sediment from the basin wall. Other material is transported across or along the basin to the deep parts of a rift lake along the escarpment margin. Most of the sediment will enter the half-graben down the hanging wall side. On the side of the basin opposite the main fault, sedimentation occurs along the hinged margin. In this part of the basin, slopes are gentle and large river systems may carry sediment into the basin
27.
Rift
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In geology, a rift is a linear zone where the Earths crust and lithosphere are being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting, where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the area may contain volcanic rocks, and active volcanism is a part of many. Major rifts occur along the axis of most mid-ocean ridges. Failed rifts are the result of rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a junction where three converging rifts meet over a hotspot. Two of these evolve to the point of spreading, while the third ultimately fails. Most rifts consist of a series of segments that together form the linear zone characteristic of rifts. The individual rift segments have a dominantly half-graben geometry, controlled by a single basin-bounding fault, segment lengths vary between rifts, depending on the elastic thickness of the lithosphere. Areas of thick colder lithosphere, such as the Baikal Rift have segment lengths in excess of 80 km, while in areas of warmer thin lithosphere, segment lengths may be less than 30 km. Along the axis of the rift the position, and in cases the polarity. Segment boundaries often have a complex structure and generally cross the rift axis at a high angle. These segment boundary zones accommodate the differences in fault displacement between the segments and are known as accommodation zones. Accommodation zones may be located where older crustal structures intersect the rift axis, in the Gulf of Suez rift, the Zaafarana accommodation zone is located where a shear zone in the Arabian-Nubian Shield meets the rift. At the onset of rifting, the part of the lithosphere starts to extend on a series of initially unconnected normal faults. In subaerial rifts, drainage at this stage is generally internal, as the rift evolves, some of the individual fault segments grow, eventually becoming linked together to form the larger bounding faults. Subsequent extension becomes concentrated on these faults, the longer faults and wider fault spacing leads to more continuous areas of fault-related subsidence along the rift axis. Significant uplift of the rift shoulders develops at this stage, strongly influencing drainage, during rifting, as the crust is thinned, the Earths surface subsides and the Moho becomes correspondingly raised
28.
Danakil Depression
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The Danakil Depression lies at the triple junction of three tectonic plates and has a complex geological history. It has developed as a result of Africa and Asia moving apart, causing rifting, erosion, inundation by the sea, the rising and falling of the ground have all played their part in the formation of this depression. Sedimentary rocks such as sandstone and limestone are unconformably overlain by basalt which resulted from extensive lava flows, the Danakil Depression is a plain, some 200 by 50 km, lying in the north of the Afar Region of Ethiopia, near the border with Eritrea. It is about 125 m below sea level and is bordered to the west by the Ethiopian Plateau and to the east by the Danakil Alps, beyond which is the Red Sea. This area is referred to as the cradle of hominids after Donald Johanson and his colleagues in 1974 found the famous Lucy Australopithecus fossil, the Danakil Depression is the hottest place on Earth in terms of year-round average temperatures. It is also one of the lowest places on the planet, here, the Awash River dries up in a chain of salt lakes such as Lake Afrera, never reaching the Indian Ocean. Mount Ayalu is the westernmost and older of the two volcanoes at the end of the Danakil Depression. The other active volcano, Erta Ale, is one of several lakes of lava bubbling from the Earths mantle. Additionally, the contains the Dallol sulfur springs, or hot springs. These wet environments at the Danakil Depression are being investigated to help understand how life might arise on other planets, any microorganisms living here will be extremophilic microbes of a major interest to astrobiologists
29.
Death Valley
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Death Valley is a desert valley located in Eastern California. It is one of the hottest places in the world at the height of summertime along with deserts in Africa, Death Valleys Badwater Basin is the point of the lowest elevation in North America, at 282 feet below sea level. This point is 84.6 miles east-southeast of Mount Whitney, Death Valleys Furnace Creek holds the record for the highest reliably recorded air temperature in the world,134 °F on July 10,1913. This has been contested by other weather experts and it is located mostly in Inyo County, California. It has an area of about 3,000 sq mi, the highest point in Death Valley itself is Telescope Peak in the Panamint Range, which has an elevation of 11,043 feet. Death Valley is one of the best geological examples of a basin and it lies at the southern end of a geological trough known as Walker Lane, which runs north into Oregon. The valley is bisected by a right lateral slip fault system, represented by the Death Valley Fault. The eastern end of the left lateral Garlock Fault intersects the Death Valley Fault, Furnace Creek and the Amargosa River flow through the valley but eventually disappear into the sands of the valley floor. Death Valley also contains salt pans, according to current geological consensus, at various times during the middle of the Pleistocene era, inland lakes formed in Death Valley. Lake Manly received water overflowing from a chain of other Pleistocene lakes, Death Valley has a subtropical, hot desert climate, with long, extremely hot summers and short, warm or mild winters, as well as little rainfall. As a general rule, lower altitudes tend to have higher temperatures, when the sun heats the ground, that heat is then radiated upward, but the dense below-sea-level air absorbs some of this radiation and radiates some of it back towards the ground. In addition, the valley walls trap rising hot air and recycle it back down to the valley floor. This process is important in Death Valley, as it provides its specific climate. The valley is surrounded by mountains, while its surface is flat and devoid of plants, so much of the suns heat can reach the ground, absorbed by soil. When air at ground level is heated, it begins to rise, moving up past steep, high mountain ranges, which then cools slightly, sinking back down towards the valley more compressed. This air is reheated by the sun to a higher temperature, moving up the mountain again, whereby the air moves up and down in a circular motion in cycles. This heated air increases ground temperature markedly, forming the hot wind currents that are trapped by atmospheric pressure and mountains, Death Valley holds temperature records because it has an unusually high number of factors that lead to high atmospheric temperatures. The depth and shape of Death Valley influence its summer temperatures, the valley is a long, narrow basin 282 feet below sea level, yet is walled by high, steep mountain ranges
30.
California
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California is the most populous state in the United States and the third most extensive by area. Located on the western coast of the U. S, California is bordered by the other U. S. states of Oregon, Nevada, and Arizona and shares an international border with the Mexican state of Baja California. Los Angeles is Californias most populous city, and the second largest after New York City. The Los Angeles Area and the San Francisco Bay Area are the nations second- and fifth-most populous urban regions, California also has the nations most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The Central Valley, an agricultural area, dominates the states center. What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries, the Spanish Empire then claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its war for independence. The western portion of Alta California then was organized as the State of California, the California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom. If it were a country, California would be the 6th largest economy in the world, fifty-eight percent of the states economy is centered on finance, government, real estate services, technology, and professional, scientific and technical business services. Although it accounts for only 1.5 percent of the states economy, the story of Calafia is recorded in a 1510 work The Adventures of Esplandián, written as a sequel to Amadis de Gaula by Spanish adventure writer Garci Rodríguez de Montalvo. The kingdom of Queen Calafia, according to Montalvo, was said to be a land inhabited by griffins and other strange beasts. This conventional wisdom that California was an island, with maps drawn to reflect this belief, shortened forms of the states name include CA, Cal. Calif. and US-CA. Settled by successive waves of arrivals during the last 10,000 years, various estimates of the native population range from 100,000 to 300,000. The Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups also were diverse in their organization with bands, tribes, villages. Trade, intermarriage and military alliances fostered many social and economic relationships among the diverse groups, the first European effort to explore the coast as far north as the Russian River was a Spanish sailing expedition, led by Portuguese captain Juan Rodríguez Cabrillo, in 1542. Some 37 years later English explorer Francis Drake also explored and claimed a portion of the California coast in 1579. Spanish traders made unintended visits with the Manila galleons on their trips from the Philippines beginning in 1565
31.
Simpson Desert
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The Simpson Desert is a large area of dry, red sandy plain and dunes in Northern Territory, South Australia and Queensland in central Australia. It is the fourth largest Australian desert, with an area of 176,500 km2 and is the worlds largest sand dune desert, the desert is underlain by the Great Artesian Basin, one of the largest inland drainage areas in the world. Water from the basin rises to the surface at numerous springs, including Dalhousie Springs. As a result of exploitation by such bores, the flow of water to springs has been decreasing in recent years. It is also part of the Lake Eyre basin, the Simpson Desert is an erg which contains the worlds longest parallel sand dunes. These north-south oriented dunes are static, held in position by vegetation and they vary in height from 3 metres in the west to around 30 metres on the eastern side. The largest dune, Nappanerica, is 40 metres in height, the explorer Charles Sturt, who visited the region from 1844–1846, was the first European to see the desert. After he returned to Adelaide, it was discovered that the links in his surveyors chain had stretched, poeppel’s border post was too far west by 300 metres. In 1884, surveyor Larry Wells moved the post to its position on the eastern bank of Lake Poeppel. The tri-state border is now known as Poeppel Corner, in 1936 Ted Colson became the first non-indigenous person to cross the desert in its entirety, riding camels. Mr Simpson was the owner of the Simpson washing machine company, in 1984, Dennis Bartel was the first white man to successfully walk solo and unsupported west-to-east across the Simpson,390 km in 24 days, relying on old Aboriginal wells for water. In 2006 Lucas Trihey was the first non-indigenous person to walk across the desert through the centre away from vehicle tracks. He carried all his equipment in a cart and crossed from East Bore on the western edge of the desert to Birdsville in the east. In 2008, Michael Giacometti completed the first, and only, starting at Bedourie in Queensland, he walked solo and unsupported, towing all his equipment, food and water in a two-wheeled cart to Old Andado homestead. Also in 2008, Belgian Louis-Philippe Loncke became the first non-indigenous person to complete a crossing of the desert on foot and unsupported. In 1967, the Queensland Government established the Simpson Desert National Park, no maintained roads cross the desert. The Donohue Highway is an outback track passing from near Boulia towards the Northern Territory border in the north of the desert. There are tracks that were created during seismic surveys in the search for gas and these include the French Line, the Rig Road, and the QAA Line
32.
Western Australia
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Western Australia is a state occupying the entire western third of Australia. It is bounded by the Indian Ocean to the north and west, the Great Australian Bight and Southern Ocean to the south, the state has about 2.6 million inhabitants, around 11% of the national total. 92% of the lives in the south-west corner of the state. The first European visitor to Western Australia was the Dutch explorer Dirk Hartog, the first European settlement of Western Australia occurred following the landing by Major Edmund Lockyer on 26 December 1826 of an expedition on behalf of the New South Wales colonial government. This was followed by the establishment of the Swan River Colony in 1829, including the site of the present-day capital, york was the first inland settlement in Western Australia. Situated 97 kilometres east of Perth, it was settled on 16 September 1831, Western Australia achieved responsible government in 1890, and federated with the other British colonies in Australia in 1901. Today its economy relies on mining, agriculture and tourism. The state produces 46% of Australias exports, Western Australia is the second-largest iron ore producer in the world. The International Hydrographic Organization designates the body of water south of the continent as part of the Indian Ocean, the total length of the states eastern border is 1,862 km. There are 20,781 km of coastline, including 7,892 km of island coastline, the total land area occupied by the state is 2.5 million km2. Most of the state is a low plateau with an elevation of about 400 metres, very low relief. This descends relatively sharply to the plains, in some cases forming a sharp escarpment. The extreme age of the landscape has meant that the soils are remarkably infertile, even soils derived from granitic bedrock contain an order of magnitude less available phosphorus and only half as much nitrogen as soils in comparable climates in other continents. Soils derived from extensive sandplains or ironstone are even less fertile, nearly devoid of soluble phosphate and also deficient in zinc, copper, molybdenum, the infertility of most of the soils has required heavy application by farmers of chemical fertilisers, particularly superphosphate, insecticides and herbicides. These have resulted in damage to invertebrate and bacterial populations, the grazing and use of hoofed mammals and, later, heavy machinery through the years have resulted in compaction of soils and great damage to the fragile soils. Large-scale land clearing for agriculture has damaged habitats for native flora, large areas of the states wheatbelt region have problems with dryland salinity and the loss of fresh water. The southwest coastal area has a Mediterranean climate and it was originally heavily forested, including large stands of karri, one of the tallest trees in the world. This agricultural region is one of the nine most bio-diverse terrestrial habitats, thanks to the offshore Leeuwin Current, the area is one of the top six regions for marine biodiversity and contains the most southerly coral reefs in the world
33.
Utah
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Utah is a state in the western United States. It became the 45th state admitted to the U. S. on January 4,1896, Utah is the 13th-largest by area, 31st-most-populous, and 10th-least-densely populated of the 50 United States. Utah has a population of more than 3 million, approximately 80% of whom live along the Wasatch Front, Utah is bordered by Colorado to the east, Wyoming to the northeast, Idaho to the north, Arizona to the south, and Nevada to the west. It also touches a corner of New Mexico in the southeast, approximately 62% of Utahns are reported to be members of The Church of Jesus Christ of Latter-day Saints or LDS, which greatly influences Utahn culture and daily life. The LDS Churchs world headquarters is located in Salt Lake City, Utah is the only state with a majority population belonging to a single church. The state is a center of transportation, education, information technology and research, government services, mining, in 2013, the U. S. Census Bureau estimated that Utah had the second fastest-growing population of any state. St. George was the metropolitan area in the United States from 2000 to 2005. Utah also has the 14th highest median income and the least income inequality of any U. S. state. A2012 Gallup national survey found Utah overall to be the best state to live in based on 13 forward-looking measurements including various economic, lifestyle, the name Utah is derived from the name of the Ute tribe. It means people of the mountains in the Ute language, according to other sources Utah is derived from the Apache name Yudah which means Tall. These Native American tribes are subgroups of the Ute-Aztec Native American ethnicity and were sedentary, the Ancestral Pueblo people built their homes through excavations in mountains, and the Fremont people built houses of straw before disappearing from the region around the 15th century. Another group of Native Americans, the Navajo, settled in the region around the 18th century, in the mid-18th century, other Uto-Aztecan tribes, including the Goshute, the Paiute, the Shoshone, and the Ute people, also settled in the region. These five groups were present when the first European explorers arrived, the southern Utah region was explored by the Spanish in 1540, led by Francisco Vásquez de Coronado, while looking for the legendary Cíbola. A group led by two Catholic priests—sometimes called the Dominguez-Escalante Expedition—left Santa Fe in 1776, hoping to find a route to the coast of California, the expedition traveled as far north as Utah Lake and encountered the native residents. The Spanish made further explorations in the region, but were not interested in colonizing the area because of its desert nature, in 1821, the year Mexico achieved its independence from Spain, the region became known as part of its territory of Alta California. European trappers and fur traders explored some areas of Utah in the early 19th century from Canada, the city of Provo, Utah was named for one, Étienne Provost, who visited the area in 1825. The city of Ogden, Utah was named after Peter Skene Ogden, in late 1824, Jim Bridger became the first known English-speaking person to sight the Great Salt Lake. Due to the salinity of its waters, Bridger thought he had found the Pacific Ocean
34.
Great Artesian Basin
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The Great Artesian Basin, located in Australia, is the largest and deepest artesian basin in the world, stretching over 1,700,000 square kilometres, with measured temperatures ranging from 30–100 °C. The basin provides the source of fresh water through much of inland Australia. The Basin underlies 23% of the continent, including the states and territories of Queensland, the Northern Territory, South Australia, the basin is 3,000 metres deep in places and is estimated to contain 64,900 cubic kilometres of groundwater. The Great Artesian Basin Coordinating Committee coordinates activity between the levels of government and community organisations. This area is one of the physiographic provinces of the larger East Australian Basins division. The water of the GAB is held in a sandstone laid down by continental erosion of higher ground during the Triassic, Jurassic. The eastern edge of the basin was uplifted when the Great Dividing Range formed, the other side was created from the landforms of the Central Eastern Lowlands and the Great Western Plateau to the west. Most recharge water enters the rock formations from relatively high ground near the edge of the basin and very gradually flows toward the south. A much smaller amount enters along the margin in arid central Australia, flowing to the south. Because the sandstones are permeable, water makes its way through the pores between the sand grains, flowing at a rate of one to five metres per year. Discharge water eventually exits through a number of springs and seeps, prior to European occupation, waters of the GAB discharged through mound springs, many in arid South Australia. These springs supported a variety of invertebrates, and supported extensive Aboriginal communities. After the arrival of Europeans, they enabled early exploration and faster communications between southeastern Australia and Europe via the Australian Overland Telegraph Line. The Great Artesian Basin became an important water supply for cattle stations, irrigation, and livestock and domestic usage, to tap it, water wells are drilled down to a suitable rock layer, where the pressure of the water forces it up, mostly without pumping. European discovery of the dates from 1878 when a shallow bore near Bourke produced flowing water. There were similar discoveries in 1886 at Back Creek east of Barcaldine, in essence, water extraction from the GAB is a mining operation, with recharge much less than current extraction rates. In 1915, there were 1,500 bores providing 2,000 megalitres of water per day and this included just under 2000 freely flowing bores and more than 9000 that required mechanical power to bring water to the surface. Many bores are unregulated or abandoned, resulting in considerable water wastage and these problems have existed for many decades, and in January 2007 the Australian Commonwealth Government announced additional funding in an attempt to bring them under control
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Sabkha
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Sabkha is a phonetic translation of the Arabic word for a salt flat. Sabkhas are supratidal, forming along coastlines and are characterized by evaporite-carbonate deposits with some siliciclastics. Sabkhas form subaerial, prograding and shoaling-upward sequences that have a thickness of a meter or less. The accepted type locality is along the coast of the Persian Gulf in the United Arab Emirates, the origin and progression of sabkha development in the Persian Gulf is discussed by Al-Farraj. In the khor-lagoon-sabkha model, a rise in sea-level floods coastal areas. If the features silt up, or the land rises, or the sea level falls, then the water evaporates, leaving a flat salt pan. If the coastal region has irregular topography, then the flooding creates large independent creeks, a khor is a shallow, subtidal flat or tidal inlet. The inlet may host grey mangroves, depending on whether less saline water is available from wadis or groundwater, as sediment begins to accumulate, the khors become more shallow and form a lagoon, or intertidal flat. The lagoons continue to fill until the floor is exposed at low tide. An immature sabkha will be inundated during higher than normal spring tides, after rainstorms, mature sabkhas are only flooded after heavy rainstorms and may eventually coalesce to form a sabkha coastal plain. These coastal plains are flat, with reliefs between 10–50 cm, and their seaward slope can be as little as 1,1,000. The flatness of a sabkha is enhanced by aeolian siliciclastic dust being deposited in the topographic lows with most of the caused by evaporites. These environments can be found laterally contemporaneous in parallel belts to the coast as well, coral reefs, barrier islands, and oolite shoals form the barrier with the open shelf. Inland of this are the supratidal sabkhas, the sabkhas can be as wide as 15 km when seaward of dune fields supplying large amounts of sediment. Sabkhas seaward of low outcrops of Miocene carbonate-evaporites or alluvial fans off the Oman fold, if the coast has dune fields, then flooding creates many smaller pools between the crests of the dunes. In some parts of the world, these lakes can form in inland deserts. For example, large parts of the Empty Quarter in Saudi Arabia, in some places, the sabkha connect to form long accessible corridors into the desert. The third picture shows the south of the crescent-shaped Liwa Oasis in the southern UAE
36.
Caspian Sea
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The Caspian Sea is the largest enclosed inland body of water on Earth by area, variously classed as the worlds largest lake or a full-fledged sea. It is in a basin located between Europe and Asia. It is bounded by Kazakhstan to the northeast, Russia to the northwest, Azerbaijan to the west, Iran to the south, the Caspian Sea lies to the east of the Caucasus Mountains and to the west of the vast steppe of Central Asia. In its northern part, the Caspian Depression lies 28 to 130 m below sea level, the sea bed in the southern part reaches as low as 1023 m below sea level, which is the second lowest natural depression on earth after Lake Baikal. The ancient inhabitants of its coast perceived the Caspian Sea as an ocean, probably because of its saltiness, the sea has a surface area of 371,000 km2 and a volume of 78,200 km3. It has a salinity of approximately 1. 2%, about a third of the salinity of most seawater, the word Caspian is derived from the name of the Caspi, an ancient people who lived to the southwest of the sea in Transcaucasia. Strabo wrote that to the country of the Albanians belongs also the territory called Caspiane, which was named after the Caspian tribe, as was also the sea, but the tribe has now disappeared. Moreover, the Caspian Gates, which is the name of a region in Irans Tehran province, the Iranian city of Qazvin shares the root of its name with that of the sea. In fact, the traditional Arabic name for the sea itself is Bahr al-Qazwin, in classical antiquity among Greeks and Persians it was called the Hyrcanian Ocean. In Persian antiquity, as well as in modern Iran, it is known as the دریای خزر, Daryā-e Khazar, ancient Arabic sources refer to it as Baḥr Gīlān meaning the Gilan Sea. Turkic languages refer to the lake as Khazar Sea, in Turkmen, the name is Hazar deňizi, in Azeri, it is Xəzər dənizi, and in modern Turkish, it is Hazar denizi. An exception is Kazakh, where it is called Каспий теңізі, old Russian sources call it the Khvalyn or Khvalis Sea after the name of Khwarezmia. In modern Russian, it is called Каспи́йское мо́ре, Kaspiyskoye more, the Caspian Sea, like the Black Sea, Namak Lake, and Lake Urmia, is a remnant of the ancient Paratethys Sea. It became landlocked about 5.5 million years ago due to tectonic uplift and a fall in sea level. Due to the current inflow of water, the Caspian Sea is a freshwater lake in its northern portions, and is most saline on the Iranian shore. Currently, the salinity of the Caspian is one third that of Earths oceans. The Caspian Sea is the largest inland body of water in the world, the coastlines of the Caspian are shared by Azerbaijan, Iran, Kazakhstan, Russia, and Turkmenistan. The Caspian is divided into three distinct regions, the Northern, Middle, and Southern Caspian
37.
Sahara
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The Sahara is the largest hot desert and the third largest desert in the world after Antarctica and the Arctic. Its area of 9,200,000 square kilometres is comparable to the area of the United States. The desert comprises much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and Sudan. It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south, it is bounded by the Sahel, a belt of tropical savanna around the Niger River valley. The Sahara can be divided into several regions including, the western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains, the Ténéré desert, the name Sahara is derived from ṣaḥārā, the plural of the Arabic word for desert. The Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Morocco, Niger, Western Sahara, Sudan and it covers 9 million square kilometres, amounting to 31% of Africa. If all areas with an annual precipitation of less than 250 mm were included. It is one of three physiographic provinces of the African massive physiographic division. The Sahara is mainly rocky hamada, Ergs form only a minor part, wind or rare rainfall shape the desert features, sand dunes, dune fields, sand seas, stone plateaus, gravel plains, dry valleys, dry lakes, and salt flats. Unusual landforms include the Richat Structure in Mauritania, several deeply dissected mountains, many volcanic, rise from the desert, including the Aïr Mountains, Ahaggar Mountains, Saharan Atlas, Tibesti Mountains, Adrar des Iforas, and the Red Sea hills. The highest peak in the Sahara is Emi Koussi, a volcano in the Tibesti range of northern Chad. The central Sahara is hyperarid, with sparse vegetation, the northern and southern reaches of the desert, along with the highlands, have areas of sparse grassland and desert shrub, with trees and taller shrubs in wadis, where moisture collects. In the central, hyperarid region, there are subdivisions of the great desert, Tanezrouft, the Ténéré, the Libyan Desert, the Eastern Desert. These extremely arid areas often receive no rain for years, the northern limit also corresponds to the 100 mm isohyet of annual precipitation. To the south, the Sahara is bounded by the Sahel, the southern limit of the Sahara is indicated botanically by the southern limit of Cornulaca monacantha, or northern limit of Cenchrus biflorus, a grass typical of the Sahel. According to climatic criteria, the limit of the Sahara corresponds to the 150 mm isohyet of annual precipitation. The Sahara is the worlds largest low-latitude hot desert and this steady descending airflow causes a warming and a drying effect in the upper troposphere
38.
Namib
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The Namib is a coastal desert in southern Africa. The name Namib is of Nama origin and means vast place, the Namibs northernmost portion, which extends 450 kilometres from the Angola-Namibia border, is known as Moçâmedes Desert, while its southern portion approaches the neighboring Kalahari Desert. From the Atlantic coast eastward, the Namib gradually ascends in elevation, annual precipitation ranges from 2 millimetres in the most arid regions to 200 millimetres at the escarpment, making the Namib the only true desert in southern Africa. Having endured arid or semi-arid conditions for roughly 55–80 million years, the desert geology consists of sand seas near the coast, while gravel plains and scattered mountain outcrops occur further inland. The sand dunes, some of which are 300 metres high, fogs that originate offshore from the collision of the cold Benguela Current and warm air from the Hadley Cell create a fog belt that frequently envelops parts of the desert. Coastal regions can experience more than 180 days of fog a year. While this has proved a hazard to ships—more than a thousand wrecks litter the Skeleton Coast—it is a vital source of moisture for desert life. Owing to its antiquity, the Namib may be home to endemic species than any other desert in the world. Most of the wildlife is arthropods and other small animals that live on little water. Near the coast, the ocean water is rich in fishery resources and supports populations of brown fur seals and shorebirds. Further inland, the Namib-Naukluft National Park, the largest game park in Africa, supports populations of African Bush Elephants, Mountain Zebras, and other large mammals. Although the outer Namib is largely barren of vegetation, lichens and succulents are found in areas, while grasses, shrubs. A few types of trees are able to survive the extremely arid climate. The Namib Desert is one of the 500 distinct physiographic provinces of the South African Platform physiographic division and it occupies an area of around 80,950 km², stretching from the[Usiab River to the town of Lüderitz and from the Atlantic Ocean to the Namib Escarpment. It is about 1,000 miles long north to south. To the south, the Namib borders on the South African Karoo semi-desert, southern Namib comprises a vast dune sea with some of the tallest and most spectacular dunes of the world, ranging in color from pink to vivid orange. In the Sossusvlei area, several dunes exceed 300 meters in height, the complexity and regularity of dune patterns in its dune sea have attracted the attention of geologists for decades, but it remains poorly understood. Moving north from Sossusvlei, the sand gradually gives way to a desert that extends all the way from Sossusvlei to the Swakop river
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Messinian salinity crisis
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It ended with the Zanclean flood, when the Atlantic reclaimed the basin. Around 5.33 Ma with the Zanclean flood, even now, the Mediterranean is saltier than the North Atlantic because of its near isolation by the Strait of Gibraltar and its high rate of evaporation. If the Strait of Gibraltar closes again, which is likely to happen in the near geological future, after that, continued northward movement of Africa may obliterate the Mediterranean, see Mediterranean Ridge. In 1867, he named the period the Messinian, for the region of Messina, since then, salt-bearing and gypsum-bearing evaporite layers in many Mediterranean countries have been dated to that period. In 1961, seismic surveying of the Mediterranean basin revealed a geological feature some 100–200 m below the seafloor. This feature, dubbed the M reflector, closely followed the contours of the present seafloor, the origin of this layer was largely interpreted as related to salt deposition. However, different interpretations were proposed for the age of salt, earlier suggestions from Denizot in 1957 and Ruggieri in 1967 proposed that this layer was Late Miocene in age, and the same Ruggieri coined the term Messinian Salinity Crisis. New and high-quality seismic data on the M-reflector were acquired in the Mediterranean Basin in 1970 and these deposits were dated and interpreted for the first time as deep-basin products of the Messinian Salinity Crisis. These layers alternated with layers containing marine fossils, indicating a succession of drying and flooding periods, the massive presence of salt does not require a desiccation of the sea. For example, the Nile cut its bed down to several hundred feet below sea level at Aswan, in many places in the Mediterranean, fossilized cracks have been found where muddy sediment had dried and cracked in the sunlight and drought. This episode comprises the part of what is called the Messinian Epoch. The Epoch was characterised by stages of tectonic activity and sea level fluctuations, as well as erosional and depositional events. The Mediterranean-Atlantic strait closed tight time and time again, and the Mediterranean Sea, for the first time and then repeatedly, partially desiccated. The basin was finally isolated from the Atlantic Ocean for a longer period, during the initial, very dry stages, there was extensive erosion, creating several huge canyon systems. Later stages are marked by cyclic evaporite deposition into a large lake-sea basin, the basin has not desiccated since. The last refilling was at the Miocene/Pliocene boundary, when the Strait of Gibraltar broke wide open permanently. Upon closely examining the Hole 124 core, Kenneth J. Hsu found that, the fine sediments deposited on a quiet or deep bottom had perfectly even lamination. As the basin was drying up and the depth decreased
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Mediterranean Sea
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The sea is sometimes considered a part of the Atlantic Ocean, although it is usually identified as a separate body of water. The name Mediterranean is derived from the Latin mediterraneus, meaning inland or in the middle of land and it covers an approximate area of 2.5 million km2, but its connection to the Atlantic is only 14 km wide. The Strait of Gibraltar is a strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Gibraltar. In oceanography, it is called the Eurafrican Mediterranean Sea or the European Mediterranean Sea to distinguish it from mediterranean seas elsewhere. The Mediterranean Sea has a depth of 1,500 m. The sea is bordered on the north by Europe, the east by Asia and it is located between latitudes 30° and 46° N and longitudes 6° W and 36° E. Its west-east length, from the Strait of Gibraltar to the Gulf of Iskenderun, the seas average north-south length, from Croatia’s southern shore to Libya, is approximately 800 km. The Mediterranean Sea, including the Sea of Marmara, has an area of approximately 2,510,000 square km. The sea was an important route for merchants and travelers of ancient times that allowed for trade, the history of the Mediterranean region is crucial to understanding the origins and development of many modern societies. In addition, the Gaza Strip and the British Overseas Territories of Gibraltar and Akrotiri, the term Mediterranean derives from the Latin word mediterraneus, meaning amid the earth or between land, as it is between the continents of Africa, Asia and Europe. The Ancient Greek name Mesogeios, is similarly from μέσο, between + γη, land, earth) and it can be compared with the Ancient Greek name Mesopotamia, meaning between rivers. The Mediterranean Sea has historically had several names, for example, the Carthaginians called it the Syrian Sea and latter Romans commonly called it Mare Nostrum, and occasionally Mare Internum. Another name was the Sea of the Philistines, from the people inhabiting a large portion of its shores near the Israelites, the sea is also called the Great Sea in the General Prologue by Geoffrey Chaucer. In Ottoman Turkish, it has also been called Bahr-i Sefid, in Modern Hebrew, it has been called HaYam HaTikhon, the Middle Sea, reflecting the Seas name in ancient Greek, Latin, and modern languages in both Europe and the Middle East. Similarly, in Modern Arabic, it is known as al-Baḥr al-Mutawassiṭ, in Turkish, it is known as Akdeniz, the White Sea since among Turks the white colour represents the west. Several ancient civilisations were located around the Mediterranean shores, and were influenced by their proximity to the sea. It provided routes for trade, colonisation, and war, as well as food for numerous communities throughout the ages, due to the shared climate, geology, and access to the sea, cultures centered on the Mediterranean tended to have some extent of intertwined culture and history. Two of the most notable Mediterranean civilisations in classical antiquity were the Greek city states, later, when Augustus founded the Roman Empire, the Romans referred to the Mediterranean as Mare Nostrum
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Jurassic
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The Jurassic is a geologic period and system that spans 56.3 million years from the end of the Triassic Period 201.3 million years ago to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles, the start of the period is marked by the major Triassic–Jurassic extinction event. The Jurassic is named after the Jura Mountains within the European Alps, by the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses, Laurasia to the north and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, on land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs, other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to a mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, the chronostratigraphic term Jurassic is directly linked to the Jura Mountains. The name Jura is derived from the Celtic root jor, which was Latinised into juria, the Jurassic period is divided into the Early Jurassic, Middle, and Late Jurassic epochs. The Jurassic System, in stratigraphy, is divided into the Lower Jurassic, Middle, the separation of the term Jurassic into three sections goes back to Leopold von Buch. The Jurassic North Atlantic Ocean was relatively narrow, while the South Atlantic did not open until the following Cretaceous period, the Tethys Sea closed, and the Neotethys basin appeared. Climates were warm, with no evidence of glaciation, as in the Triassic, there was apparently no land over either pole, and no extensive ice caps existed. In contrast, the North American Jurassic record is the poorest of the Mesozoic, the Jurassic was a time of calcite sea geochemistry in which low-magnesium calcite was the primary inorganic marine precipitate of calcium carbonate. Carbonate hardgrounds were thus very common, along with calcitic ooids, calcitic cements, the first of several massive batholiths were emplaced in the northern American cordillera beginning in the mid-Jurassic, marking the Nevadan orogeny. Important Jurassic exposures are found in Russia, India, South America, Japan, Australasia. As the Jurassic proceeded, larger and more groups of dinosaurs like sauropods and ornithopods proliferated in Africa. Middle Jurassic strata are well represented nor well studied in Africa. Late Jurassic strata are also poorly represented apart from the spectacular Tendaguru fauna in Tanzania, the Late Jurassic life of Tendaguru is very similar to that found in western North Americas Morrison Formation. During the Jurassic period, the primary living in the sea were fish
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Clastic
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Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus, chunks and smaller grains of rock broken off other rocks by physical weathering. Geologists use the term clastic with reference to sedimentary rocks as well as to particles in sediment transport whether in suspension or as bed load, clastic sedimentary rocks are rocks composed predominantly of broken pieces or clasts of older weathered and eroded rocks. Clastic sediments or sedimentary rocks are classified based on size, clast and cementing material composition. The classification factors are often useful in determining a samples environment of deposition, an example clastic environment would be a river system in which the full range of grains being transported by the moving water consist of pieces eroded from solid rock upstream. Grain size varies from clay in shales and claystones, through silt in siltstones, sand in sandstones, the Krumbein phi scale numerically orders these terms in a logarithmic size scale. Siliciclastic rocks are clastic rocks that are composed almost exclusively of silicon. The composition of sedimentary rocks includes the chemical and mineralogical components of the framework as well as the cementing material that make up these rocks. Boggs divides them into four categories, major minerals, accessory minerals, rock fragments, major minerals can be categorized into subdivisions based on their resistance to chemical decomposition. Those that possess a great resistance to decomposition are categorized as stable, while those that do not are considered less stable, the most common stable mineral in siliciclastic sedimentary rocks is quartz. Quartz makes up approximately 65 percent of framework grains present in sandstones, less stable minerals present in this type of rocks are feldspars, including both potassium and plagioclase feldspars. Feldspars comprise a considerably lesser portion of framework grains and minerals and they only make up about 15 percent of framework grains in sandstones and 5% of minerals in shales. Clay mineral groups are present in mudrocks but can be found in other siliciclastic sedimentary rocks at considerably lower levels. Accessory minerals are associated with those whose presence in the rock are not directly important to the classification of the specimen and these generally occur in smaller amounts in comparison to the quartz, and feldspars. Furthermore, those that do occur are generally heavy minerals or coarse grained micas, rock fragments also occur in the composition of siliciclastic sedimentary rocks and are responsible for about 10 -15 percent of the composition of sandstone. They generally make up most of the gravel size particles in conglomerates, though they sometimes are, rock fragments are not always sedimentary in origin. They can also be metamorphic or igneous, chemical cements vary in abundance but are predominantly found in sandstones. The two major types, are based and carbonate based
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Pseudomorph
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The name literally means false form. Terminology for pseudomorphs is replacer after original, as in brookite after rutile, an infiltration pseudomorph, or substitution pseudomorph is a pseudomorph in which one mineral or other material is replaced by another. The original shape of the mineral remains unchanged, but color, hardness, an example of this process is the replacement of wood by silica to form petrified wood in which the substitution may be so perfect as to retain the original cellular structure of the wood. An example of substitution is replacement of aragonite twin crystals by native copper, as occurs at the Corocoro United Copper Mines of Coro Coro. A variety of infiltration or substitution pseudomorphism is called alteration, in only partial replacement occurs. This happens typically when a mineral of one composition changes by chemical reaction to another of similar composition, an example is a change from galena to anglesite. The resulting pseudomorph may contain a core of galena surrounded by anglesite that has the cubic crystal shape of galena. A paramorph is a mineral changed on the level only. It has the chemical composition, but with a different structure. The mineral looks identical to the original unaltered form and this occurs, as an example, in the aragonite to calcite change. An incrustation pseudomorph, also called perimorph, results from a process by which a mineral is coated by another, the encasing mineral remains intact, and retains the shape of the original mineral or material. Alternatively, another mineral may fill the previously occupied by some other mineral or material. Pseudomorphs are also common in paleontology, fossils are often formed by pseudomorphic replacement of the remains by mineral matter. Examples include petrified wood and pyritized gastropod shells, in biology, a pseudomorph is a cloud of mucus-rich ink released by many species of cephalopod. The name refers to the similarity in appearance between the cephalopod that released it and the cloud itself, in context meaning literally false body. This behaviour often allows the cephalopod to escape from predation unharmed, danas Manual of Mineralogy by Cornelis S. Hurlbut, Eighteenth Edition, ISBN 0-471-42225-8 Polymorphism
44.
Fertilizer
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A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soils or to plant tissues to supply one or more plant nutrients essential to the growth of plants. Fertilizers enhance the growth of plants and this goal is met in two ways, the traditional one being additives that provide nutrients. The second mode by which some fertilizers act is to enhance the effectiveness of the soil by modifying its water retention and aeration and this article, like many on fertilizers, emphasises the nutritional aspect. The nutrients required for plant life are classified according to the elements. Instead compounds containing these elements are the basis of fertilizers, the macronutrients are consumed in larger quantities and are present in plant tissue in quantities from 0. 15% to 6. 0% on a dry matter basis. Plants are made up of four elements, hydrogen, oxygen, carbon. Carbon, hydrogen and oxygen are widely available as water and carbon dioxide, although nitrogen makes up most of the atmosphere, it is in a form that is unavailable to plants. Nitrogen is the most important fertilizer since nitrogen is present in proteins, DNA, to be nutritious to plants, nitrogen must be made available in a fixed form. Only some bacteria and their host plants can fix atmospheric nitrogen by converting it to ammonia, phosphate is required for the production of DNA and ATP, the main energy carrier in cells, as well as certain lipids. Micronutrients are consumed in quantities and are present in plant tissue on the order of parts-per-million, ranging from 0.15 to 400 ppm DM. These elements are present at the active sites of enzymes that carry out the plants metabolism. Because these elements enable catalysts their impact far exceeds their weight percentage, Fertilizers are classified in several ways. They are classified according to whether they provide a single nutrient, multinutrient fertilizers provide two or more nutrients, for example N and P. Fertilizers are also sometimes classified as inorganic versus organic. Inorganic fertilizers exclude carbon-containing materials except ureas, organic fertilizers are usually plant- or animal-derived matter. Inorganic are sometimes called synthetic fertilizers since various chemical treatments are required for their manufacture, the main nitrogen-based straight fertilizer is ammonia or its solutions. Ammonium nitrate is widely used. Urea is another source of nitrogen, having the advantage that it is solid and non-explosive, unlike ammonia and ammonium nitrate. A few percent of the fertilizer market has been met by calcium ammonium nitrate
