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Cavern
Caves or caverns are natural voids under the Earth's surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance underground (such as rock shelters). Caves which extend further underground than the opening is wide are called endogene caves. Speleology is the science of exploration and study of all aspects of caves and the cave environment. Visiting or exploring caves for recreation may be called ''caving'', ''potholing'', or ''spelunking''. Formation types The formation and development of caves is known as ''speleogenesis''; it can occur over the course of millions of years. Caves can range widely in size, and are formed by various geological processes. These may involve a combination of chemical processes, erosion by water, tectonic forces, microorganisms, pressure, and atmospheric influences. Isotopic dating techniques can be applied to cave sediments, to determine the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinkhole
A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water enters into underground passages known as ''ponor'', swallow hole or swallet. A ''cenote'' is a type of sinkhole that exposes groundwater underneath. ''Sink'', and ''stream sink'' are more general terms for sites that drain surface water, possibly by infiltration into sediment or crumbled rock. Most sinkholes are caused by Karst topography, karst processes – the chemical dissolution of carbonate rocks, collapse or suffosion processes. Sinkholes are usually circular and vary in size from tens to hundreds of Metre, meters both in diameter and depth, and vary in form from soil-lined bowls to bedrock-edged chasms. Sinkholes may form gradually or suddenly, and are found worldwide. Formation Natural processes Sinkholes may capture surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karst
Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some evidence that karst may occur in more weathering-resistant rocks such as quartzite given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. In regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of ''paleokarst'' (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's Oil and gas reserves and resource quantification, hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems. Etymology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stalagmite
A stalagmite (, ; ; ) is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typically composed of calcium carbonate, but may consist of lava, mud, peat, pitch, sand, sinter, and amberat (crystallized urine of pack rats). The corresponding formation hanging down from the ceiling of a cave is a stalactite. Formation and type Limestone stalagmites The most common stalagmites are speleothems, which usually form in limestone caves. Stalagmite formation occurs only under certain pH conditions within the cavern. They form through deposition of calcium carbonate and other minerals, which is precipitated from mineralized water solutions. Limestone is the chief form of calcium carbonate rock, which is dissolved by water that contains carbon dioxide, forming a calcium bicarbonate solution in caverns. The partial pressure of carbon dioxide in the water must be great ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stalactite
A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension (chemistry), suspension, or is capable of being melting, melted, may form a stalactite. Stalactites may be composed of lava, minerals, mud, peat, pitch (resin), pitch, sand, Geyserite, sinter, and amberat (crystallized urine of pack rats). A stalactite is not necessarily a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves. The corresponding formation on the floor of the cave is known as a stalagmite. Formation and type Limestone stalactites The most common stalactites are speleothems, which occur in limestone caves. They form through Deposition (geology), deposition of calcium carbonate and other minerals, which is precipitated from mineralized water Solution (chemistry), solutio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speleothem
A speleothem (; ) is a geological formation made by mineral deposits that accumulate over time in natural caves. Speleothems most commonly form in calcareous caves due to carbonate dissolution reactions. They can take a variety of forms, depending on their depositional history and environment. Their chemical composition, gradual growth, and preservation in caves make them useful paleoclimatic proxies. Chemical and physical characteristics More than 300 variations of cave mineral deposits have been identified. The vast majority of speleothems are calcareous, composed of calcium carbonate (CaCO3) minerals (calcite or aragonite). Less commonly, speleothems are made of calcium sulfate ( gypsum or mirabilite) or opal. Speleothems of pure calcium carbonate or calcium sulfate are translucent and colorless. The presence of iron oxide or copper provides a reddish brown color. The presence of manganese oxide can create darker colors such as black or dark brown. Speleothems can also b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calcium Carbonate
Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skeletons and pearls. Materials containing much calcium carbonate or resembling it are described as calcareous. Calcium carbonate is the active ingredient in agricultural lime and is produced when calcium ions in hard water react with carbonate ions to form limescale. It has medical use as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause hypercalcemia and digestive issues. Chemistry Calcium carbonate shares the typical properties of other carbonates. Notably, it: *reacts with acids, releasing carbonic acid which quickly disintegrates into carbon dioxide and water: : *releases carbon dioxide upon heating, called a thermal decomposition reaction, or calcination (to above 840 °C in the case of ), t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science), crystal forms of calcium carbonate . Limestone forms when these minerals Precipitation (chemistry), precipitate out of water containing dissolved calcium. This can take place through both biological and nonbiological processes, though biological processes, such as the accumulation of corals and shells in the sea, have likely been more important for the last 540 million years. Limestone often contains fossils which provide scientists with information on ancient environments and on the evolution of life. About 20% to 25% of sedimentary rock is carbonate rock, and most of this is limestone. The remaining carbonate rock is mostly Dolomite (rock), dolomite, a closely related rock, which contains a high percentage of the mineral Dolomite (mine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caving
Caving, also known as spelunking (United States and Canada) and potholing (United Kingdom and Ireland), is the recreational pastime of exploring wild cave systems (as distinguished from show caves). In contrast, speleology is the scientific study of caves and the cave environment.Caving in New Zealand (from Te Ara: The Encyclopedia of New Zealand, Accessed 2012-11.) The challenges involved in caving vary according to the cave being visited; in addition to the total absence of light beyond the entrance, negotiating pitches, squeezes, and water hazards can be difficult. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speleology
Speleology () is the scientific study of caves and other karst features, as well as their chemical composition, composition, structure, physical property, physical properties, history, ecology, and the processes by which they form (speleogenesis) and change over time (speleomorphology). The term ''speleology'' is also sometimes applied to the recreational activity of exploration, exploring caves, but this is more properly known as ''caving'', ''potholing'' (British English), or ''spelunking'' (United States and Canadian English). Speleology and caving are often connected, as the physical skills required for ''in situ'' study are the same. Speleology is a cross-disciplinary field that combines the knowledge of chemistry, biology, geology, physics, meteorology, and cartography to develop portraits of caves as complex, evolving systems. History Before modern speleology developed, John Beaumont (geologist), John Beaumont wrote detailed descriptions of some Mendip Hills, Mendip c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weathering
Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Weathering processes are either physical or chemical. The former involves the breakdown of rocks and soils through such mechanical effects as heat, water, ice and wind. The latter covers reactions to water, atmospheric gases and biologically produced chemicals with rocks and soils. Water is the principal agent behind both kinds, though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important. Biological chemical weathering is also called biological weathering. The materials left after the rock breaks down combine with organic material to create so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedding Planes
In geology, a bed is a layer of sediment, sedimentary rock, or volcanic rock "bounded above and below by more or less well-defined bedding surfaces".Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds., 2005. ''Glossary of Geology'' (5th ed.). Alexandria, Virginia; American Geological Institute. p 61. A bedding surface or bedding plane is respectively a curved surface or plane that visibly separates each successive bed (of the same or different lithology) from the preceding or following bed. In cross sections, bedding surfaces or planes are often called bedding contacts. Within conformable successions, each bedding surface acted as the depositional surface for the accumulation of younger sediment. Definitions Specifically in sedimentology, a bed can be defined in one of two major ways.Davies, N.S., and Shillito, A.P. 2021, ''True substrates: the exceptional resolution and unexceptional preservation of deep time snapshots on bedding surfaces.'' ''Sedimentology.'' publish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helictite
A helictite is a speleothem (cave-formed mineral) found in a Solution cave, limestone cave that changes its axis from the vertical at one or more stages during its growth. Helictites have a curving or angular form that looks as if they were grown in zero gravity. They are most likely the result of Capillary action, capillary forces acting on tiny water droplets, a force often strong enough at this scale to defy gravity. Helictites are, perhaps, the most delicate of cave formations. They are usually made of needle-form calcite and aragonite. Helictite forms have been described in several types: ribbon helictites, saws, rods, butterflies, "hands", curly-fries, and "clumps of worms". They typically have symmetry (biology)#Radial symmetry, radial symmetry. They can be easily crushed or broken by the slightest touch. Because of this, helictites are rarely seen within arm's reach in Tourism, tourist caves. Timpanogos Cave National Monument in Utah has one of the largest collections o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
