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Adel Mountains Volcanic Field
The Adel Mountains Volcanic Field (also known as the Adel Mountains, Adel Volcanics, and Adel Mountain Volcanics) is an ancient volcanic field of heavily eroded 75-million-year-oldGunderson, Jay A. and Sheriff, Steven D. "A New Late Cretaceous Paleomagnetic Pole from the Adel Mountains, West Central Montana." ''Journal of Geophysical Research.'' 96:B1 (January 10, 1991).Harlan, Stephen S.; Geissman, John W.; Snee, Lawrence W.; and Reynolds, Richard L. "Late Cretaceous Remagnetization of Proterozoic Mafic Dikes, Southern Highland Mountains, Southwestern Montana: A Paleomagnetic and 40Ar/39Ar Study." ''Geological Society of America Bulletin.'' 108:6 (June 1996). igneous rocks about 40 miles long and 20 miles wide (800 square miles, or 2,071 square kilometers)Merrill-Maker, Andrea. ''Montana Almanac.'' 2d ed. Guilford, Conn.: Globe Pequot, 2005. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adel Volcanics
Adel may refer to: Places United States * Adel, Georgia * Adel, Indiana * Adel, Iowa * Adel Township, Dallas County, Iowa * Adel, Oklahoma * Adel, Oregon * Adel Mountains Volcanic Field, West-central Montana Elsewhere * Adelaide, Australia * Adel, Leeds, England * Adilabad, Telangana, India * Adilabad district, Telangana, India * Al-Adel, Baghdad, Iraq * Adel, Republic of Bashkortostan, Russia * Adel Sultanate People *Adel (name), a unisex first name of northern-European origin, or a last name * Adil, an Arabic first name (male) and last name Other uses *Adel (official), a public official in Morocco *Adel, German nobility *Adel, Dutch nobility *Adel, Danish nobility *Adel, Swedish nobility *Adel, Norwegian nobility *Adel, Finnish nobility *Adel, Icelandic nobility *''Adel'', an Egyptian ferry that capsized and sank in May 1963 *Adel, a game character of ''Final Fantasy VIII'' *Adel, a weevil/beetle genus of the Pentarthrini tribe See also *Adelaide (disambiguat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglomerate (geology)
Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fills the interstices between the clasts. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form by the consolidation and lithification of gravel. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. In terms of origin and depositional mechanisms, they are closely related to sandstones and exhibit many of the same types of sedimentary structures, e.g., tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and sedimentary rocks.'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highwood Mountains
The Highwood Mountains are an island range (sub-range of the Rockies entirely surrounded by prairie) which cover approximately 4,659 km² (1,799 sq mi) of the Central Montana Alkalic Province in north central Montana in the U.S. They are in Chouteau, Judith Basin and Cascade counties and lie east of Great Falls and Benton Lake National Wildlife Refuge, at the northern end of the Lewis and Clark National Forest. The mountains were included in Highwood Mountains National Forest until 1908, when the unit became part of Lewis and Clark National Forest. Nearby are Highwood, Montana and the Missouri River above the mouth of the Marias River. The highest point in the Highwood Mountains is Highwood Baldy at 2338 meters (7670 ft). The area has volcanic origins and is rich in potash. Many of the extrusive rocks and some of the dike rocks contain abundant phenocrysts of a clear analcime that appears to be primary. Pseudoleucite is an abundant constituent of many of the igne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horse (geology)
A horse, in geology, is any block of rock completely separated from the surrounding rock either by mineral veins or fault planes. In mining, a horse is a block of country rock entirely encased within a mineral lode. In structural geology the term was first used to describe the thrust-bounded imbricates found within a thrust duplex. In later literature it has become a general term for any block entirely bounded by faults, whether the overall deformation type is contractional, extensional or strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ... in nature. References External links * Tectonics Rock formations Structural geology {{tectonics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Fault
A thrust fault is a break in the Earth's crust, across which older rocks are pushed above younger rocks. Thrust geometry and nomenclature Reverse faults A thrust fault is a type of reverse fault that has a dip of 45 degrees or less. If the angle of the fault plane is lower (often less than 15 degrees from the horizontal) and the displacement of the overlying block is large (often in the kilometer range) the fault is called an ''overthrust'' or ''overthrust fault''. Erosion can remove part of the overlying block, creating a ''fenster'' (or ''window'') – when the underlying block is exposed only in a relatively small area. When erosion removes most of the overlying block, leaving island-like remnants resting on the lower block, the remnants are called ''klippen'' (singular ''klippe''). Blind thrust faults If the fault plane terminates before it reaches the Earth's surface, it is referred to as a ''blind thrust'' fault. Because of the lack of surface evidence, blind thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laramide Orogeny
The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute. The Laramide orogeny occurred in a series of pulses, with quiescent phases intervening. The major feature that was created by this orogeny was deep-seated, thick-skinned deformation, with evidence of this orogeny found from Canada to northern Mexico, with the easternmost extent of the mountain-building represented by the Black Hills of South Dakota. The phenomenon is named for the Laramie Mountains of eastern Wyoming. The Laramide orogeny is sometimes confused with the Sevier orogeny, which partially overlapped in time and space. The orogeny is commonly attributed to events off the west coast of North America, where the Kula and Farallon Plates were sliding under the North American plate. Most hypotheses propos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cascade, Montana
Cascade is a town in Cascade County, Montana, United States. The population was 600 at the 2020 census. It is part of the Great Falls, Montana Metropolitan Statistical Area, which in 2020 had a population of 84,414. Cascade was incorporated in 1911. History The founder of the town was Mr. Thomas Graham. Originally named Dodge, the town changed its name in 1887. This was an appeal to become the county seat of the newly formed county. Geography Cascade is located at (47.271954, -111.702675). Interstate 15 passes through the community, with access from Exits 254 and 256. The town is situated along the Missouri River. According to the United States Census Bureau, the town has a total area of , all land. Climate According to the Köppen Climate Classification system, Cascade has a semi-arid climate, abbreviated "BSk" on climate maps. Demographics 2010 census As of the census of 2010, there were 685 people, 287 households, and 188 families living in the town. The population de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fort Shaw, Montana
Fort Shaw is a census-designated place (CDP) in Cascade County, Montana, United States. The population was 280 at the 2010 census. Named for a former United States military outpost, it is part of the Great Falls, Montana Metropolitan Statistical Area. First called Camp Reynolds, Fort Shaw is named for Col. Robert G. Shaw of Boston, the first white officer to lead a unit of the United States Colored Troops in the American Civil War. The U.S. government established this fort on the Mullan Road in 1867. A community developed around it. Geography Fort Shaw is located at (47.504313, -111.811348). It is situated on Montana Highway 200. The Sun River flows north of town. According to the United States Census Bureau, the CDP has a total area of , all land. Demographics As of the census of 2000, there were 274 people, 101 households, and 73 families residing in the CDP. The population density was 48.6 people per square mile (18.8/km2). There were 115 housing units at an average de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laccolith
A laccolith is a body of intrusive rock with a dome-shaped upper surface and a level base, fed by a conduit from below. A laccolith forms when magma (molten rock) rising through the Earth's crust begins to spread out horizontally, prying apart the host rock strata. The pressure of the magma is high enough that the overlying strata are forced upward, giving the laccolith its dome-like form. Over time, erosion can expose the solidified laccolith, which is typically more resistant to weathering than the host rock. The exposed laccolith then forms a hill or mountain. The Henry Mountains of Utah, US, are an example of a mountain range composed of exposed laccoliths. It was here that geologist Grove Karl Gilbert carried out pioneering field work on this type of intrusion. Laccolith mountains have since been identified in many other parts of the world. Description A laccolith is a type of igneous intrusion, formed when magma forces its way upwards through the Earth's crust but co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interstate Highway System
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. The system extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico. The U.S. federal government first funded roadways through the Federal Aid Road Act of 1916, and began an effort to construct a national road grid with the passage of the Federal Aid Highway Act of 1921. In 1926, the United States Numbered Highway System was established, creating the first national road numbering system for cross-country travel. The roads were still state-funded and maintained, however, and there was little in the way of national standards for road design. U.S. Highways could be anything from a two-lane country road to a major multi-lane freeway. After Dwight D. Eisenhower became president in 1953, his administr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Plug
A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged magma is trapped beneath it, and this can sometimes lead to an explosive eruption. In a plinian eruption the plug is destroyed and ash is ejected. Glacial erosion can lead to exposure of the plug on one side, while a long slope of material remains on the opposite side. Such landforms are called crag and tail. If a plug is preserved, erosion may remove the surrounding rock while the erosion-resistant plug remains, producing a distinctive upstanding landform. Examples of volcanic plugs Africa Near the village of Rhumsiki in the Far North Province of Cameroon, Kapsiki Peak is an example of a volcanic plug and is one of the most photographed parts of the Mandara Mountains. Spectacular volcanic plugs are present in the center of La ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
