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North Table Mountain
North Table Mountain is a mesa on the eastern flank of the Front Range of the Rocky Mountains of North America. The mesa summit is located in North Table Mountain Park, north by east ( bearing 9°) of downtown Golden, Colorado, United States, in Jefferson County. Mesa The most distinctive feature of the mesa is its nearly flat cap that was formed by ancient Paleocene lava flows. It is separated from companion South Table Mountain, which consists of the same geologic formation, by Clear Creek. North Table Mountain is a popular scenic and recreational destination in the Denver metro area, and it is preserved as public open space by Jefferson County and the Access Fund. Recent and ongoing projects by Jefferson County Open Space have resulted in the construction of several new trails and eliminated large numbers of unofficial trails. Geology North Table Mountain is underlain by sedimentary rocks of the Denver Formation, which spans the interval from latest Cretaceous t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lookout Mountain (Colorado)
Lookout Mountain is a foothill on the eastern flank of the Front Range of the Rocky Mountains of North America. The peak is located in Lookout Mountain Park, west-southwest ( bearing 245°) of downtown Golden in Jefferson County, Colorado, United States. Mountain Downtown Denver, 12 miles to the east, can be seen clearly from the mountain. It is known for its natural scenery and has played a major role in area recreation, transportation, water supply and telecommunications. The summit is famous as the gravesite of William Frederick "Buffalo Bill" Cody and has several sites listed on the National Register of Historic Places. Its earliest known inhabitants were the Ute tribe of American Indians, who used the mountain as a lookout point upon the surrounding region. In 1890, the ''Denver Resort Railway and Telegraph Company'' built a narrow-gauge railroad to the mountain from Denver, but failed to complete or open it despite being listed as an operating railroad by the In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Flows
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric Dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of Earth itself, and can also be used to date a wide range of natural and man-made materials. Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geologic time scale. Among the best-known techniques are radiocarbon dating, potassium–argon dating and uranium–lead dating. By al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
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. On Earth, volcanoes are most often found where tectonic plates are diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monzonite
Monzonite is an igneous intrusive rock, formed by slow cooling of underground magma that has a moderate silica content and is enriched in alkali metal oxides. Monzonite is composed mostly of plagioclase and alkali feldspar. Syenodiorite is an obsolescent term for monzonite or for monzodiorite.Le Maitre, R.W., ''Igneous Rocks: A Classification and Glossary of Terms'' Cambridge University Press, 2nd ed, pp. 113 Larvikite is a particular form of monzonite. Description Monzonite is a coarse-grained (phaneritic) igneous rock. Such rocks are classified by their relative percentages of quartz, plagioclase, alkali feldspar, and feldspathoid (the QAPF classification). Monzonite is defined as rock having less than 5% quartz in its QAPF fraction and in which alkali feldspar makes up between 35% and 65% of the total feldspar content. If quartz constitutes greater than 5% of the QAPF fraction, the rock is termed a quartz monzonite, while if feldspathoids are present as up to 10% of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Columnar Jointing
Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as Joint (geology), joints, result in the formation of a regular array of polygonal Prism (geometry), prisms, or columns. Columnar jointing occurs in many types of igneous rocks and forms as the rock cools and contracts. Columnar jointing can occur in cooling lava flows and ashflow tuffs (ignimbrites), as well as in some shallow intrusions. Columnar jointing also occurs rarely in sedimentary rocks if they have been heated by nearby hot magma. The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. They are typically parallel and straight, but can also be curved and vary in diameter. An array of regular, straight, and larger-diameter columns is called a colonnade; an irregular, less-straight, and smaller-diameter array is termed an entablature. The number of sides of the individual columns can vary from 3 to 8, with 6 sides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Australia and Ant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denver Formation
The Denver Formation is a geological formation that is present within the central part of the Denver Basin that underlies the Denver, Colorado, area. It ranges in age from latest Cretaceous (Maastrichtian) to early Paleocene, and includes sediments that were deposited before, during and after the Cretaceous-Paleogene boundary event.Tweto, O. 1979. Geologic map of Colorado. U.S. Geological Survey, Map G77115. The formation is known for its paleontological resources, including dinosaur remains that are found in the Late Cretaceous part of the formation, and it includes aquifers that are important sources of water for the area. Stratigraphy The Denver Formation rests on the Arapahoe Formation, and its base is marked by the first appearance of tuffaceous sediments. It is overlain by the Dawson Arkose. In 2002 the Denver Formation was included as part of a larger unconformity-bounded unit named the D1 sequence, in order to facilitate basin-wide studies and avoid confusion arising ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Paleocene Lava Flows Cap The Summit Of North Table Mountain
{{disambiguation, geo ...
Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early Branch, a stream in Missouri * Early County, Georgia Other uses * ''Early'' (Scritti Politti album), 2005 * ''Early'' (A Certain Ratio album), 2002 * Early (name) * Early effect, an effect in transistor physics * Early Records, a record label * the early part of the morning See also * Earley (other) Earley is a town in England. Earley may also refer to: * Earley (surname), a list of people with the surname Earley * Earley (given name), a variant of the given name Earlene * Earley Lake, a lake in Minnesota *Earley parser, an algorithm *Earley ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jefferson County Open Space
Jefferson may refer to: Names * Jefferson (surname) * Jefferson (given name) People * Thomas Jefferson (1743–1826), third president of the United States * Jefferson (footballer, born 1970), full name Jefferson Tomaz de Souza, Brazilian football midfielder * Jefferson (footballer, born 1978), full name Jefferson Fredo Rodrigues, Brazilian football midfielder * Jefferson (footballer, born 1981), full name Jefferson Vieira da Cruz, Brazilian football striker * Jefferson (footballer, born 1982), full name Jefferson Charles de Souza Pinto, Brazilian football midfielder * Jefferson (footballer, born 1983), full name Jefferson de Oliveira Galvão, Brazilian football goalkeeper * Jefferson (footballer, born January 1988), full name Jefferson Andrade Siqueira, Brazilian football striker * Jefferson (footballer, born July 1988), full name Jefferson Moreira Nascimento, Brazilian football left-back * Jefferson (footballer, born August 1988), full name Jefferson Lopes Faustino, Brazi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Fund
{{Infobox organization , name = The Access Fund , image = The Access Fund Logo.jpg , image_size = 200px , caption = , map = , map_size = , map_alt = , map_caption = , type = Advocacy group , founded_date = , tax_id = 94-3131165 {{Cite web , title = GuideStar Exchange Reports for Access Fund , work = GuideStar , accessdate = 2014-03-19 , url = http://www.guidestar.org/organizations/94-3131165/access-fund.aspx , location = Boulder, CO , coordinates = , key_people = , area_served = United States , products = , services = , focus = , mission = The Access Fund is the national organization that keeps climbing areas open and conserves the climbing environment. , revenue = $2,025,000 (2015){{Cite web, url=http://2015annualreport.accessfund.org/?_ga=1.205859283.1104754604.1462216143, title = 2015 Access Fund Annual Report , expense ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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