clays

Relative density Relative density or specific gravity of the coal depends on the rank of the coal and degree of mineral impurity. Knowledge of the density of each coal ply is necessary to determine the properties of composites and blends. The density of the coal seam is necessary for conversion of resources into reserves. Relative density is normally determined by the loss of a sample's weight in water. This is best ach ...

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Coal assay, Coal assay - Chemical properties of coal, Coal assay - Physical and Mechanical Properties, Coal assay - Special Combustion Tests

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Specific Energy Aside from physical or chemical analyses to determine the handling and pollutant profile of a coal, the energy output of a coal is determined using a bomb calorimeter which measures the specific energy output of a coal during complete combustion. This is required particularly for coals used in steam-raising. Ash Fusion Test The behaviour of a coal's ash residue at high temperature is a critical factor in selecting coals for steam power generation. Most furnaces are designed to remove as ...

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Coal assay, Coal assay - Chemical properties of coal, Coal assay - Physical and Mechanical Properties, Coal assay - Special Combustion Tests

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Do not hammer at rock outcrops aimlessly, and never leave rock fragments scattered over fields or roads. The irresponsible destruction of an outcrop in search of one or two fossils is not welcomed. Fossils should be collected sparingly, and preferably without the use of a hammer. Often the best fossils are those which have been weathered out of the rock over a long period of time. They may be visible on the surface of the rock, or among the loose scree at the foot of an outcrop. Searching for fossils on the ...

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Collecting fossils, Collecting fossils - Finding fossils, Collecting fossils - Collecting ethics, Collecting fossils - Field collecting, Collecting fossils - Equipment, Collecting fossils - Preservation and documentation

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Always record field notes, such as the locality, types of rock, and fossils seen in a sturdy notebook using waterproof ink. A long tape measure is useful to record the levels of the beds in which you find fossils, and a camera may also be useful for taking photographs of fossils in situ. Detailed field notes are an essential part of your records, both from the point of view of keeping an accurate account of your collecting activities, and as an indispensable aid in the subsequent identification of your finds. Your field notes may in t ...

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Collecting fossils, Collecting fossils - Finding fossils, Collecting fossils - Collecting ethics, Collecting fossils - Field collecting, Collecting fossils - Equipment, Collecting fossils - Preservation and documentation

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Most classifications rely on some combination of the number of days of rainfall, the total amount of annual rainfall, temperature, humidity, or other factors. In 1953, Peveril Meigs divided desert regions on Earth into three categories according to the amount of precipitation they received. In this now widely accepted system, extremely arid lands have at least 12 consecutive months without rainfall, arid lands have less than 250 millimeters of annual rainfall, and semiarid lands have a mean annual precipitation of between 250 and 500 millimeters. Arid and extremely arid land are deserts, and semiarid grassl ...

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Desert, Desert - Types of desert, Desert - Montane deserts, Desert - Desert features, Desert - Soils, Desert - Vegetation, Desert - Water, Desert - Mineral resources, Desert - List of deserts, Desert - Americas, Desert - Africa, Desert - Asia-Pacific, Desert - Other

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Some mineral deposits are formed, improved, or preserved by geologic processes that occur in arid lands as a consequence of climate. Ground water leaches ore minerals and redeposits them in zones near the water table. This leaching process concentrates these minerals as ore that can be mined. Evaporation in arid lands enriches mineral accumulation in their lakes. Playas may be sources of mineral deposits formed by evaporation. Water evaporating in closed basins precipitates minerals such as gypsum, salts (including sodium nitrate and ...

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Desert, Desert - Types of desert, Desert - Montane deserts, Desert - Desert features, Desert - Soils, Desert - Vegetation, Desert - Water, Desert - Mineral resources, Desert - List of deserts, Desert - Americas, Desert - Africa, Desert - Asia-Pacific, Desert - Other

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Desert - Americas. Atacama desert in Chile Mojave, Great Basin, Sonoran, and Chihuahuan See also: List of North American deserts Desert - Africa. Libyan Kalahari Sahara Namib Desert - Asia-Pacific. Dasht-e Kavir, central Iran. Gobi desert of Mongolia; Taklamakan desert in China. Kara Kum deserts in Central Asia. Thar-Cholistan desert i ...

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Desert, Desert - Types of desert, Desert - Montane deserts, Desert - Desert features, Desert - Soils, Desert - Vegetation, Desert - Water, Desert - Mineral resources, Desert - List of deserts, Desert - Americas, Desert - Africa, Desert - Asia-Pacific, Desert - Other

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Flax, or L. usitatissimum, is grown both for seed and for fibre. The seeds produce linseed oil, which is one of the oldest commercial oils and which has been used for centuries as a drying oil in painting and varnishing. The use of flax seed and flax seed oil (which is high in omega-3 linolenic acid) as a nutritional supplement is increasing. Consuming one to two tablespoons of ground flax seeds (from a coffee or spice grinder) or one teaspoon of fresh flax seed oil daily is a possible alternative to oily fish or fish oil supplements ...

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Flax, Flax - Usage of Flax, Flax - Cultivating flax, Flax - Dressing flax, Flax - Trivia

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Coal is formed from plant remains that have been compacted, hardened, chemically altered, and metamorphosed by heat and pressure over geologic time. Coal was formed in swamp ecosystems which persisted in lowland sedimentary basins similar to the peat swamps of Borneo and Kalimantan today. These swamp environments were formed during slow subsidence of passive continental margins, and most seem to have formed adjacent to estuarine and marine sediments suggesting that they may have ...

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Coal, Coal - Etymology and folklore, Coal - Composition, Coal - Creation, Coal - Types of coal, Coal - Uses, Coal - Coal as fuel, Coal - Coking and use of coke, Coal - Harmful effects of coal burning, Coal - Coal fires, Coal - World coal reserves

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The presence of sulfuric acid in potash alum was known to the alchemists. J. H. Pott and A. S. Marggraf demonstrated that alumina was another constituent. Pott in his Lithogeognosia showed that the precipitate obtained when an alkali is poured into a solution of alum is quite different from lime and chalk, with which it had been confounded by G.E. Stahl. Marggraf showed that alumina is one of the constituents of alum, but that this earth possesses peculiar properties, and is one of the ingredients in common clay. He also showed that c ...

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Alum, Alum - Alchemical and later discoveries and uses, Alum - Pliny's writings, Alum - Alum from alunite, Alum - Alum from clays or bauxite, Alum - Types of alum, Alum - Potash alum, Alum - Soda alum, Alum - Chrome alum, Alum - Ammonium alum, Alum - Alum solubility, Alum - Uses

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Alum - Potash alum. Potash alum, K2SO4·Al2(SO4)3·24H2O, crystallizes in regular octahedra and is very soluble in water. The solution reddens litmus and is an astringent. When heated to nearly a red heat it gives a porous, friable mass which is known as "burnt alum." It fuses at 92 °C in its own water of crystallization. "Neutral alum" is obtained by the addition of as much sodium carbonate to a solution of alum as will begin to cause the separat ...

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Alum, Alum - Alchemical and later discoveries and uses, Alum - Pliny's writings, Alum - Alum from alunite, Alum - Alum from clays or bauxite, Alum - Types of alum, Alum - Potash alum, Alum - Soda alum, Alum - Chrome alum, Alum - Ammonium alum, Alum - Alum solubility, Alum - Uses

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Shaving alum is a powdered form of alum used as an astringent to prevent bleeding from small shaving cuts. The styptic pencils sold for this purpose contain aluminium sulfate or potassium aluminium sulfate. Similar products are also used on animals to prevent bleeding after nail-clipping. Crystal deodorant: Alum was used in the past as a natural underarm deodorant in Mexico, Thailand, and the Far East and in the Philippines where it is called Tawas. Man-Made Egg: Alum can be used in combination with several other chemicals to crea ...

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Alum, Alum - Alchemical and later discoveries and uses, Alum - Pliny's writings, Alum - Alum from alunite, Alum - Alum from clays or bauxite, Alum - Types of alum, Alum - Potash alum, Alum - Soda alum, Alum - Chrome alum, Alum - Ammonium alum, Alum - Alum solubility, Alum - Uses

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Weathering - Carbonation-solution. Carbonation occurs on rocks which contain calcium carbonate such as limestone and chalk. This takes place when rain combines with carbon dioxide or an organic acid to form a weak carbonic acid which reacts with calcium carbonate and forms calcium bicarbonate. The reactions as follows: CO2 + H2O ⇌ H2CO3 carbon dioxide + water ⇌ carbonic acid H2See also:

Weathering, Weathering - Mechanical Physical Weathering, Weathering - Exfoliation, Weathering - Freeze-thaw, Weathering - Pressure release, Weathering - Salt-crystal growth, Weathering - Organic Activity, Weathering - Abrasion, Weathering - Chemical Weathering, Weathering - Carbonation-solution, Weathering - Hydration, Weathering - Hydrolysis, Weathering - Oxidation, Weathering - Acids rain and plants

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Carbon is relatively safe. Inhalation of fine soot in large quantities can be dangerous. Carbon may catch fire at very high temperatures and burn vigorously (as in the Windscale fire). There are a tremendous number of carbon compounds; some are lethally poisonous (cyanide, CN-), and some are essential to life (dextrose). ...

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Carbon, Carbon - Notable characteristics, Carbon - Applications, Carbon - Other uses, Carbon - History and Etymology, Carbon - Allotropes, Carbon - Occurrence, Carbon - Organic compounds, Carbon - Carbon chains, Carbon - Carbon cycle, Carbon - Isotopes, Carbon - Precautions

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Originating from within the bactritoid nautiloids, Ammonites first appeared in the Late Silurian to Early Devonian (~400 million years ago) and became extinct at the close of the Cretaceous along with the dinosaurs (65 million years ago). The classification of ammonites is based in part on the ornamentation and structure of the septa comprising their shells' gas chambers; by these and other characteristics we can divide this subclass into three orders and eight known suborders. While nearly all nautiloids show gently curving sutures, the amm ...

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Ammonite, Ammonite - Classification, Ammonite - Life, Ammonite - Shell anatomy and diversity, Ammonite - Basic shell anatomy, Ammonite - Sexual dimorphism, Ammonite - Variations in shape, Ammonite - The aptychus, Ammonite - Size, Ammonite - Ammonite distribution, Ammonite - Trivia, Ammonite - References and further reading

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Because ammonites and their close relatives are extinct, little is known about their way of life. Their soft body parts are practically never preserved in any detail. Nonetheless, a lot has been worked out by examining ammonite shells and by using models of these shells in water tanks. Many ammonites probably lived in the open water of ancient seas, rather than at the sea bottom; this is suggested by the fact that their fossils are often found in rocks that were laid down under conditions where no benthic (bottom-dwelling) life is fou ...

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Ammonite, Ammonite - Classification, Ammonite - Life, Ammonite - Shell anatomy and diversity, Ammonite - Basic shell anatomy, Ammonite - Sexual dimorphism, Ammonite - Variations in shape, Ammonite - The aptychus, Ammonite - Size, Ammonite - Ammonite distribution, Ammonite - Trivia, Ammonite - References and further reading

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Starting from the late Silurian, ammonites were extremely abundant, especially in the Mesozoic seas. Many genera evolved and ran their course quickly, becoming extinct in a few million years. Due to their rapid evolution and widespread distribution, ammonites are useful for geologists and paleontologists for biostratigraphy. They are excellent index fossils, and it is often possible to link the rock layer in which t ...

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Ammonite, Ammonite - Classification, Ammonite - Life, Ammonite - Shell anatomy and diversity, Ammonite - Basic shell anatomy, Ammonite - Sexual dimorphism, Ammonite - Variations in shape, Ammonite - The aptychus, Ammonite - Size, Ammonite - Ammonite distribution, Ammonite - Trivia, Ammonite - References and further reading

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In medieval times, ammonites were believed to be petrified snakes. They were frequently fitted with carved snake-like heads and sold to pilgrims. A famous example of this links the ammonite fossils common in the Jurassic sediments around Whitby, North Yorkshire with the legend that St. Hilda turned a plague of snakes into stone. Even today, tourists can buy ammonite fossils with heads carved onto them to make them look more snake-like. It is said that the original discus used by the ancient Greeks in their Olympics was in fact a fossilized ammonite; a number of ammonite generic names include an explicit reference to the discus ...

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Ammonite, Ammonite - Classification, Ammonite - Life, Ammonite - Shell anatomy and diversity, Ammonite - Basic shell anatomy, Ammonite - Sexual dimorphism, Ammonite - Variations in shape, Ammonite - The aptychus, Ammonite - Size, Ammonite - Ammonite distribution, Ammonite - Trivia, Ammonite - References and further reading

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Boggs, J.R., 2000, Principles of sedimentology and stratigraphy, 3rd ed. Toronto: Merril Publishing Company. ISBN 0130996963 Folk, R.L., 1965, Petrology of sedimentary rocks PDF version. Austin: Hemphill’s Bookstore. 2nd ed. 1981, ISBN 0914696149 Pettijohn, F.J., P.E. Potter and R. Siever, 1987, Sand and sandstone, 2nd ed. Springer-Verlag. ISBN 0387963502 Scholle, P.A., 1978, A Color illustrated guide to constituents, textures, cements, and porosities of sandstones and associated rocks, American Association of Petro ...

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Sandstone, Sandstone - Origins, Sandstone - Types of sandstone, Sandstone - Basic References

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Once the geological characteristics of a sandstone have been established, it can then be assigned to one of three broad groups: arkosic sandstones, which have a high (>25%) feldspar content. quartzose sandstones which have a high (>90%) quartz content. Sometimes these sandstones are termed "orthoquartzites", e.g., the Tuscarora Quartzite of the Ridge-and-valley Appalachians. argillaceous sandstones, such as greywacke, which have a significant clay or silt content. Dholpur beige, rajpura pink,marson co ...

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Sandstone, Sandstone - Origins, Sandstone - Types of sandstone, Sandstone - Basic References

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The first known mention of the idea was in the writings of Anaxagoras, but panspermia theory was dormant until the nineteenth century when it was revived in modern form by several scientists, including Hermann von Helmholtz in 1879. Panspermia can be said to be either interstellar (between star systems) or interplanetary (between planets in the same solar system). There is as yet no compelling evidence to support or contradict it, although the majority view holds that panspermia — especially in its interstellar form — is unlikely give ...

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Panspermia, Panspermia - The panspermia theory, Panspermia - Evidence, Panspermia - Narrow time window for geogenesis, Panspermia - Extremophiles, Panspermia - Wider range of potential habitats for life, Panspermia - Evidence of extraterrestrial life, Panspermia - Objections to panspermia and exogenesis, Panspermia - Directed panspermia, Panspermia - Science fiction

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A second prominent proponent of panspermia is Nobel prize winner Professor Francis Crick, OM FRS, who along with Leslie Orgel proposed the theory of directed panspermia in 1973. This suggests that the seeds of life may have been purposely spread by an advanced extraterrestrial civilization. Crick argues that small grains containing DNA, or the building blocks of life, fired randomly in all directions is the best, most cost effective strategy for seeding life on a compatible planet at some time in the future. The strategy might have been pursued by a civilization facing catastrophic annihilation, or h ...

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Panspermia, Panspermia - The panspermia theory, Panspermia - Evidence, Panspermia - Narrow time window for geogenesis, Panspermia - Extremophiles, Panspermia - Wider range of potential habitats for life, Panspermia - Evidence of extraterrestrial life, Panspermia - Objections to panspermia and exogenesis, Panspermia - Directed panspermia, Panspermia - Science fiction

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