1.
Geology of the Grand Canyon area
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The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. The nearly 40 major sedimentary rock exposed in the Grand Canyon. Most were deposited in warm, shallow seas and near ancient, both marine and terrestrial sediments are represented, including fossilized sand dunes from an extinct desert. There are at least 14 known unconformities in the record found in the Grand Canyon. Uplift of the region started about 75 million years ago during the Laramide orogeny, in total, the Colorado Plateau was uplifted an estimated 2 miles. The adjacent Basin and Range Province to the west started to form about 18 million years ago as the result of crustal stretching, a drainage system that flowed through what is today the eastern Grand Canyon emptied into the now lower Basin and Range province. Opening of the Gulf of California around 6 million years ago enabled a large river to cut its way northeast from the gulf, the new river captured the older drainage to form the ancestral Colorado River, which in turn started to form the Grand Canyon. Wetter climates brought upon by ice ages starting 2 million years ago greatly increased excavation of the Grand Canyon, volcanic activity deposited lava over the area 1.8 million to 500,000 years ago. At least 13 lava dams blocked the Colorado River, forming lakes that were up to 2,000 feet deep, the end of the last ice age and subsequent human activity has greatly reduced the ability of the Colorado River to excavate the canyon. Dams in particular have upset patterns of sediment transport and deposition, controlled floods from Glen Canyon Dam upstream have been conducted to see if they have a restorative effect. Earthquakes and mass wasting erosive events still affect the region, at about 2.5 and 1.8 billion years ago in Precambrian time, sand, mud, silt, and ash were laid down in a marine basin adjacent to an orogenic belt. From 1.8 to 1.6 billion years ago at least two island arcs collided with the proto-North American continent and this process of plate tectonics compressed and grafted the marine sediments in the basin onto the mainland and uplifted them out of the sea. Later, these rocks were buried 12 miles under the surface and this is the resistant rock now exposed at the bottom of the canyon in the Inner Gorge. As the volcanic islands collided with the mainland around 1.7 billion years ago, blobs of magma rose from the subduction zone and these plutons slowly cooled to form the Zoroaster Granite, part of which would later be metamorphosed into gneiss. This rock unit can be seen as light-colored bands in the darker garnet-studded Vishnu Schist, the intrusion of the granite occurred in three phases, two during the initial Vishnu metamorphism period, and a third around 1.4 billion years ago. The third phase was accompanied by faulting, particularly along north—south faults. The collision expanded the continent from the Wyoming–Colorado border into Mexico, part of this thickening created the 5-to-6-mile high ancestral Mazatzal Mountains. Subsequent erosion lasting 300 million years stripped much of the exposed sediments and this reduced the very high mountains to small hills a few tens to hundreds of feet high
2.
Lithostratigraphy
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Lithostratigraphy is a sub-discipline of stratigraphy, the geological science associated with the study of strata or rock layers. Major focuses include geochronology, comparative geology, and petrology, in general a stratum will be primarily igneous or sedimentary relating to how the rock was formed. Sedimentary layers are laid down by deposition of sediment associated with weathering processes and these layers are distinguishable as having many fossils and are important for the study of biostratigraphy. Igneous layers are either plutonic or volcanic in character depending upon the rate of the rock. These layers are generally devoid of fossils and represent intrusions and volcanic activity occurred over the geologic history of the area. There are a number of principles that are used to explain the appearance of stratum, when an igneous rock cuts across a formation of sedimentary rock, then we can say that the igneous intrusion is younger than the sedimentary rock. The principle of states that a sedimentary rock layer in a tectonically undisturbed stratum is younger than the one beneath. The principle of original horizontality states that the deposition of sediments occurs as essentially horizontal beds, a lithostratigraphic unit conforms to the law of superposition, which state that in any succession of strata, not disturbed or overturned since deposition, younger rocks lies above older rocks. The principle of continuity states that a set of bed extends. Lithostratigraphic units are recognized and defined on the basis of observable rock characteristics, the descriptions of strata based on physical appearance define facies. Lithostratigraphic units are defined by lithic characteristics, and not by age. Stratotype, A designated type of unit consisting of rocks that contain clear-cut characteristics which are representative of a particular lithostratigraphic unit. Lithosome, Masses of rock of essentially uniform character and having interchanging relationships with adjacent masses of different lithology, the fundamental Lithostratigraphic unit is the formation. A formation is a lithologically distinctive stratigraphic unit that is enough to be mappable and traceable. Formations may be subdivided into members and beds and aggregated with other formations into groups and supergroups, two types of contact, conformable and unconformable. Conformable, unbroken deposition, no break or hiatus, the surface strata resulting is called a conformity. Two types of contact between conformable strata, abrupt contacts and gradational contact, the surface stratum resulting is called an unconformity. Four types of unconformity, Angular unconformity, younger sediment lies upon a surface of tilted or folded older rocks
3.
Geologist
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A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes that shape it. Geologists usually study geology, although backgrounds in physics, chemistry, biology, field work is an important component of geology, although many subdisciplines incorporate laboratory work. Some geologists work in the mining business searching for metals, oils and they are also in the forefront of natural hazards and disasters prevention and mitigation, studying natural hazards such as earthquakes, volcanic activity, tsunamis, weather storms. Their studies are used to warn the public of the occurrence of these events. Geologists are also important contributors to climate change discussions, james Hutton is often viewed as the first modern geologist. In 1785 he presented a paper entitled Theory of the Earth to the Royal Society of Edinburgh, Hutton published a two-volume version of his ideas in 1795. The first geological map of the U. S. was produced in 1809 by William Maclure, in 1807, Maclure commenced the self-imposed task of making a geological survey of the United States. Almost every state in the Union was traversed and mapped by him and this antedates William Smiths geological map of England by six years, although it was constructed using a different classification of rocks. Sir Charles Lyell first published his famous book, Principles of Geology and this book, which influenced the thought of Charles Darwin, successfully promoted the doctrine of uniformitarianism. This theory states that slow geological processes have occurred throughout the Earths history and are still occurring today, in contrast, catastrophism is the theory that Earths features formed in single, catastrophic events and remained unchanged thereafter. Though Hutton believed in uniformitarianism, the idea was not widely accepted at the time, most geologists also need skills in GIS and other mapping techniques. Geology students often spend portions of the year, especially the summer though sometimes during a January term, geologists may concentrate their studies or research in one or more of the following disciplines, Dendrochronology, the study of dating based on tree ring patterns. Economic geology, the study of ore genesis, and the mechanisms of ore creation, geochemistry, the applied branch deals with the study of the chemical makeup and behaviour of rocks, and the study of the behaviour of their minerals. Geochronology, the study of isotope geology specifically toward determining the date within the past of rock formation, metamorphism, mineralization and geological events. Geomorphology, the study of landforms and the processes that create them Hydrogeology, igneous petrology, the study of igneous processes such as igneous differentiation, fractional crystallization, intrusive and volcanological phenomena. Isotope geology, the case of the composition of rocks to determine the processes of rock. Metamorphic petrology, the study of the effects of metamorphism on minerals, marine geology, the study of the seafloor, involves geophysical, geochemical, sedimentological and paleontological investigations of the ocean floor and coastal margins. Marine geology has strong ties to physical oceanography and plate tectonics, palaeoclimatology, the application of geological science to determine the climatic conditions present in the Earths atmosphere within the Earths history
4.
Outcrop
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An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. However, in places where the cover is removed through erosion or tectonic uplift. In Finland, glacial erosion during the last glacial maximum, followed by scouring by sea waves, bedrock and superficial deposits may also be exposed at the Earths surface due to human excavations such as quarrying and building of transport routes. Outcrops allow direct observation and sampling of the bedrock in situ for geologic analysis, in situ measurements are critical for proper analysis of geological history and outcrops are therefore extremely important for understanding the geologic time scale of earth history. Outcrops are also important for understanding fossil assemblages, paleo-environment. An outcrop example in California is the Vasquez Rocks, familiar from location shooting use in many films, list of rock formations Geological formation Geologic time scale Media related to Outcrops at Wikimedia Commons
5.
Metamorphic rock
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Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means change in form. The original rock is subjected to heat and pressure, causing profound physical and/or chemical change, the protolith may be a sedimentary, an igneous, or even an existing type of metamorphic rock. Metamorphic rocks make up a part of the Earths crust. They are classified by texture and by chemical and mineral assemblage and they may be formed simply by being deep beneath the Earths surface, subjected to high temperatures and the great pressure of the rock layers above it. They can form from tectonic processes such as continental collisions, which cause horizontal pressure and they are also formed when rock is heated up by the intrusion of hot molten rock called magma from the Earths interior. The study of rocks provides information about the temperatures and pressures that occur at great depths within the Earths crust. Some examples of rocks are gneiss, slate, marble, schist. Metamorphic minerals are those that only at the high temperatures and pressures associated with the process of metamorphism. These minerals, known as index minerals, include sillimanite, kyanite, staurolite, andalusite, and some garnet. Other minerals, such as olivines, pyroxenes, amphiboles, micas, feldspars, and quartz, may be found in metamorphic rocks and these minerals formed during the crystallization of igneous rocks. They are stable at temperatures and pressures and may remain chemically unchanged during the metamorphic process. However, all minerals are only within certain limits. The change in the size of the rock during the process of metamorphism is called recrystallization. Both high temperatures and pressures contribute to recrystallization, high temperatures allow the atoms and ions in solid crystals to migrate, thus reorganizing the crystals, while high pressures cause solution of the crystals within the rock at their point of contact. The layering within metamorphic rocks is called foliation, and it occurs when a rock is being shortened along one axis during recrystallization. This causes the platy or elongated crystals of minerals, such as mica and chlorite and this results in a banded, or foliated rock, with the bands showing the colors of the minerals that formed them. Textures are separated into foliated and non-foliated categories, foliated rock is a product of differential stress that deforms the rock in one plane, sometimes creating a plane of cleavage. For example, slate is a metamorphic rock, originating from shale
6.
Volcano
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A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. Earths volcanoes occur because its crust is broken into 17 major, therefore, on Earth, volcanoes are generally found where tectonic plates are diverging or converging. This type of volcanism falls under the umbrella of plate hypothesis volcanism, Volcanism away from plate boundaries has also been explained as mantle plumes. These so-called hotspots, for example Hawaii, are postulated to arise from upwelling diapirs with magma from the boundary,3,000 km deep in the Earth. Volcanoes are usually not created where two plates slide past one another. Erupting volcanoes can pose hazards, not only in the immediate vicinity of the eruption. Historically, so-called volcanic winters have caused catastrophic famines, the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is called volcanology, sometimes spelled vulcanology, at the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock. Most divergent plate boundaries are at the bottom of the oceans, therefore, most volcanic activity is submarine, black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed, for example, subduction zones are places where two plates, usually an oceanic plate and a continental plate, collide. In this case, the plate subducts, or submerges under the continental plate forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the temperature of the overlying mantle wedge. This magma tends to be very viscous due to its high content, so it often does not reach the surface. When it does reach the surface, a volcano is formed, typical examples of this kind of volcano are Mount Etna and the volcanoes in the Pacific Ring of Fire. Because tectonic plates move across them, each volcano becomes dormant and is eventually re-formed as the plate advances over the postulated plume and this theory is currently under criticism, however. The most common perception of a volcano is of a mountain, spewing lava and poisonous gases from a crater at its summit, however. The features of volcanoes are more complicated and their structure. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have features such as massive plateaus
7.
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
8.
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
9.
Capitol Reef National Park
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Capitol Reef National Park is a United States National Park, in south-central Utah. The park is approximately 60 miles long on its north–south axis, the park was established in 1971 to preserve 241,904 acres of desert landscape and is open all year with May through September being the highest visitation months. Located partially in Wayne County, Utah, the area was originally named Wayne Wonderland in the 1920s by local boosters Ephraim P. Pectol, easy road access only came in 1962 with the construction of State Route 24 through the Fremont River Canyon. The majority of the nearly 100 mi long up-thrust formation called the Waterpocket Fold—a rocky spine extending from Thousand Lake Mountain to Lake Powell—is preserved within the park, Capitol Reef is the name of an especially rugged and spectacular segment of the Waterpocket Fold by the Fremont River. The local word reef refers to any rocky barrier to land travel, Capitol Reef encompasses the Waterpocket Fold, a warp in the earths crust that is 65 million years old. It is the largest exposed monocline in North America, in this fold, newer and older layers of earth folded over each other in an S-shape. This warp, probably caused by the same colliding continental plates that created the Rocky Mountains, has weathered and eroded over millennia to expose layers of rock, the park is filled with brilliantly colored sandstone cliffs, gleaming white domes, and contrasting layers of stone and earth. The fold forms a barrier that even today has barely been breached by roads. Early settlers referred to parallel, impassable ridges as reefs, from which the park gets the half of its name. The first paved road was constructed through the area in 1962, today, State Route 24 cuts through the park traveling east and west between Canyonlands National Park and Bryce Canyon National Park, but few other paved roads invade the rugged landscape. The park is filled with canyons, cliffs, towers, domes, the Fremont River has cut canyons through parts of the Waterpocket Fold, but most of the park is arid desert country. A scenic drive shows park visitors some of the highlights, hundreds of miles of trails and unpaved roads lead the more adventurous into the equally scenic backcountry. Fremont culture Native Americans lived near the perennial Fremont River in the part of the Capitol Reef Waterpocket Fold around the year 1000. They irrigated crops of lentils, maize, and squash and stored their grain in stone granaries, in the 13th century, all of the Native American cultures in this area underwent sudden change, likely due to a long drought. The Fremont settlements and fields were abandoned, many years after the Fremont left, Paiutes moved into the area. These Numic speaking people named the Fremont granaries moki huts and thought they were the homes of a race of people or moki. In 1872 Alan H. Thompson, an attached to United States Army Major John Wesley Powells expedition. Geologist Clarence Dutton later spent several summers studying the areas geology, none of these expeditions explored the Waterpocket Fold to any great extent, however
10.
Canyonlands National Park
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Canyonlands National Park is a U. S. National Park located in southeastern Utah near the town of Moab. It preserves a colorful landscape eroded into countless canyons, mesas, and buttes by the Colorado River, the Green River, legislation creating the park was signed into law by President Lyndon Johnson on September 12,1964. The park is divided into four districts, the Island in the Sky, the Needles, the Maze, while these areas share a primitive desert atmosphere, each retains its own character. Author Edward Abbey, a frequent visitor, described the Canyonlands as the most weird, wonderful, Canyonlands is a popular recreational destination. Since 2007, more than 400,000 people have visited the park each year with a record of 776,218 visitors in 2016, the geography of the park is well suited to a number of different recreational uses. Hikers, mountain bikers, backpackers, and four-wheelers all enjoy traveling the rugged, the White Rim Road traverses the White Rim Sandstone level of the park between the rivers and the Island in the Sky. Since 2015, day-use permits must be obtained before travelling on the White Rim Road due to the popularity of driving and bicycling along it. The park services intent is to provide a wilderness experience for all visitors while minimizing impacts on the natural surroundings. Rafters and kayakers float the calm stretches of the Green River, below the Confluence, Cataract Canyon contains powerful whitewater rapids, similar to those found in the Grand Canyon. However, since there is no large impoundment on the Colorado River above Canyonlands National Park, river flow through the Confluence is determined by snowmelt, not management. As a result, and in combination with Cataract Canyons unique graben geology, as of 2016, the Island in the Sky district, with its proximity to the Moab, Utah area, attracts 76.7 percent of total park visitors. The Needles district is the second most visited, drawing 20.7 percent of visitors, the remote Maze district accounts for only about 1.5 percent of visitors, while river rafters and other river users account for the remaining 1.1 percent of total park visitation. Political compromise at the time of the parks creation limited the area to an arbitrary portion of the Canyonlands basin. Conservationists hope to complete the park by bringing the boundaries up to the high sandstone rims that form the border of the Canyonlands landscape. The Colorado River and Green River combine within the park dividing it into three districts called the Island in the Sky, the Needles and the Maze, the Colorado River flows through Cataract Canyon below its confluence with the Green River. The area was home of the Ancestral Puebloans, of which many traces can be found. Although the items and tools used have been largely taken away by looters, some of their stone. The Ancestral Puebloans also left traces in the form of petroglyphs, the Maze district is located west of the Colorado and Green rivers, and is the least accessible section of the park, and one of the most remote and inaccessible areas of the United States
11.
Paleontology
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Paleontology or palaeontology is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene Epoch. It includes the study of fossils to determine organisms evolution and interactions with each other, paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuviers work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek παλαιός, palaios, i. e. old, ancient, ὄν, on, i. e. being, creature and λόγος, logos, i. e. speech, thought, study. Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of modern humans. It now uses techniques drawn from a range of sciences, including biochemistry, mathematics. The final quarter of the 20th century saw the development of molecular phylogenetics, molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend. The simplest definition is the study of ancient life, paleontology is one of the historical sciences, along with archaeology, geology, astronomy, cosmology, philology and history itself. This means that it aims to describe phenomena of the past, hence it has three main elements, description of the phenomena, developing a general theory about the causes of various types of change, and applying those theories to specific facts. Sometimes the smoking gun is discovered by an accident during other research. Paleontology lies on the boundary between biology and geology since paleontology focuses on the record of past life but its source of evidence is fossils. In addition paleontology often uses techniques derived from other sciences, including biology, osteology, ecology, chemistry, techniques developed in engineering have been used to analyse how ancient organisms might have worked, for example how fast Tyrannosaurus could move and how powerful its bite was. As knowledge has increased, paleontology has developed specialised subdivisions, vertebrate paleontology concentrates on fossils of vertebrates, from the earliest fish to the immediate ancestors of modern mammals. Invertebrate paleontology deals with fossils of such as molluscs, arthropods. Paleobotany focuses on the study of plants, but traditionally includes the study of fossil algae. Palynology, the study of pollen and spores produced by plants and protists. Micropaleontology deals with all microscopic fossil organisms, regardless of the group to which they belong, one example is the development of oxygenic photosynthesis by bacteria, which hugely increased the productivity and diversity of ecosystems. This also caused the oxygenation of the atmosphere, together, these were a prerequisite for the evolution of the most complex eukaryotic cells, from which all multicellular organisms are built
12.
Cave
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A cave is a hollow place in the ground, specifically a natural underground space large enough for a human to enter. Caves form naturally by the weathering of rock and often extend deep underground, the word cave can also refer to much smaller openings such as sea caves, rock shelters, and grottos. A cavern is a type of cave, naturally formed in soluble rock with the ability to grow speleothems. Speleology is the science of exploration and study of all aspects of caves, visiting or exploring caves for recreation may be called caving, potholing, or spelunking. The formation and development of caves is known as speleogenesis, which can occur over the course of millions of years, caves are formed by various geologic processes and can be variable sizes. These may involve a combination of processes, erosion from water, tectonic forces, microorganisms, pressure. Isotopic dating techniques can be applied to cave sediments, in order to determine the timescale when geologic events may have occurred to help form and it is estimated that the maximum depth of a cave cannot be more than 3,000 metres due to the pressure of overlying rocks. For karst caves the maximum depth is determined on the basis of the limit of karst forming processes. Most caves are formed in limestone by dissolution, solutional caves or karst caves are the most frequently occurring caves and such caves form in rock that is soluble. Most occur in limestone, but they can form in other rocks including chalk, dolomite, marble, salt. Rock is dissolved by acid in groundwater that seeps through bedding planes, faults, joints. Over geological epochs cracks expand to become caves and cave systems, the largest and most abundant solutional caves are located in limestone. Limestone dissolves under the action of rainwater and groundwater charged with H2CO3, the dissolution process produces a distinctive landform known as karst, characterized by sinkholes and underground drainage. Limestone caves are often adorned with calcium carbonate formations produced through slow precipitation and these include flowstones, stalactites, stalagmites, helictites, soda straws and columns. These secondary mineral deposits in caves are called speleothems, the portions of a solutional cave that are below the water table or the local level of the groundwater will be flooded. Lechuguilla Cave in New Mexico and nearby Carlsbad Cavern are now believed to be examples of type of solutional cave. They were formed by H2S gas rising from below, where reservoirs of oil give off sulfurous fumes and this gas mixes with ground water and forms H2SO4. The acid then dissolves the limestone from below, rather than from above, caves formed at the same time as the surrounding rock are called primary caves
