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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 I ... [...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 often also 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. Etymology The word ''lava'' comes from Italian and is probably derived from the Latin word ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiometric Dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to Chronological dating, date materials such as Rock (geology), rocks or carbon, in which trace radioactive impurity, impurities were selectively incorporated when they were formed. The method compares the abundance of a naturally occurring Radionuclide, radioactive isotope within the material to the abundance of its Radioactive decay, decay products, which form at a known constant rate of decay. Radiometric dating of minerals and rocks was pioneered by Ernest Rutherford (1906) and Bertram Boltwood (1907). Radiometric dating is now the principal source of information about the Absolute dating, absolute age of rocks and other Geology, geological features, including the age of Paleontology, fossilized life forms or the age of Earth itself, and can also be used to date a wide range of natural and Artifact (archaeology), man-made materials. Together with stratigraphy, stratigraphic principles, ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcano
A volcano is commonly defined as a vent or fissure 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 because most of Earth's plate boundaries are underwater, most volcanoes 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 resulting from divergent tectonic activity are usually non-explosive whereas those resulting from convergent tectonic activity cause violent eruptions."Mid-ocean ridge tectonics, volcanism and geomorphology." Geology 26, no. 455 (2001): 458. https://macdonald.faculty.geol.ucsb.edu/papers/Macdonald%20Mid-Ocean%20Ridge%20Tectonics.pdf Volcanoes can also form where there is str ... [...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 ... [...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 (e.g. basalt, andesite, rhyolite), 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, due to a combination of Solution_(chemistry), dissolution and Precipitation_(chemistry), reprecipitation of interstitial minerals (often quartz or cryptocrystalline silica) by hot, hydrothermal fluids and the expansion and contraction of the rock unit, both resulting from the presence of a nearby Igneous intrusion, magmatic intrusion. The columns can vary from 3 meters to a few centimeters in diameter, and can be as much as 30 meters tall. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent 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, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denver Formation
The Denver Formation is a geological Formation (geology), formation that is present within the central part of the Denver Basin that underlies the Denver, Colorado, area. It ranges in age from Late Cretaceous, 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 paleontology, 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 facilita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Paleocene Lava Flows Cap The Summit Of North Table Mountain
Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican dancehall and reggae deejay Earlando Arrington Neil (1957–1994) * Early James, stage name of American singer-songwriter Fredrick Mullis Jr. (born 1993) * ''Early'' (Scritti Politti album), 2005 * ''Early'' (A Certain Ratio album), 2002 * Early Records, a record label Other uses * Early (name), a list of people and fictional characters with the given name or surname * Early effect, an effect in transistor physics * Early, a synonym for ''hotter'' in stellar classification See also * * The Earlies, a 21st century band * Earley (other) * Earlie Earlie is a masculine given name which may refer to: * Earlie Fires (born 1947), American jockey * Earlie Thomas (1945–2022), American National Football League player * Earlie Endr ... [...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) * Jefferson (singer) or Geoff Turton (born 1944), British singer Places Canada *Jefferson, Alberta United States *Jefferson, Alabama *Jefferson, Columbia County, Arkansas *Jefferson, Jefferson County, Arkansas * Jefferson, Colorado *Jefferson, Camden County, Georgia *Jefferson, Georgia, the county seat of Jackson County *Jefferson, Indiana *Jefferson, Iowa * Jefferson, Kansas *Jeffersontown, Kentucky, originally known as Jefferson *Jefferson, Louisiana *Jefferson, Maine *Jefferson, Maryland *Jefferson, Massachusetts, a village in the town of Holden *Jefferson, Minnesota *Jefferson, New Hampshire *Jefferson, New York, a town **Jefferson (CDP), New York, main hamlet in the town *Jefferson, North Carolina *Jefferson, Ohio *Jefferson, Oklahoma *Jefferson, Oregon *Jefferson, Greene County, Pennsy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Access Fund
The Access Fund is a not-for-profit rock climbing advocacy group in the US. Their goals are twofold. First, keeping climbing areas open and gaining access to currently closed climbing areas. Second, they promote an ethic of responsible climbing and conservation of the climbing environment. The Access Fund was originally the access committee of the American Alpine Club and was created as the climbing community realized the need for an organization to represent climbing and climbers' rights in the US.Fields, Jenn. 20 years of the Access Fund: Climbing advocacy organization celebrates anniversary with Boulder events, ''Colorado Daily'' (October 21, 2011). The Access Fund became its own 501(c)3 organization in 1991. The organization is based out of Boulder, Colorado Boulder is a List of municipalities in Colorado#Home rule municipality, home rule city in Boulder County, Colorado, United States, and its county seat. With a population of 108,250 at the 2020 United States census, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
