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Abo Formation
The Abo Formation is a geologic formation in New Mexico. It contains fossils characteristic of the Cisuralian epoch of the Permian period. Description The Abo Formation consists of fluvial redbed mudstones and sandstones, including river channel deposits in its lower beds (Scholle Member) and distinctive sandstone sheets in its upper beds (Cañon de Espinoso Member.) Its depositional environment was typical of the "wet red beds" of tropical Pangaea. It is extensively exposed in the mountains and other uplifts bordering the Rio Grande Rift, with a thickness of at the type section. It is also present in the subsurface in the Raton Basin. The base of the Abo is gradational with the Madera Group, and is usually placed at the first massive marine limestone bed below the fluvial sediments of the Abo. It is overlain by the Yeso Formation, with the base of the Yeso placed at the first massive sandstone bed showing frosted grains and other eolian features. The transition zone between th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formation (stratigraphy)
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness (geology), thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Beds
Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain thin beds of conglomerate, marl, limestone, or some combination of these sedimentary rocks. The ferric oxides, which are responsible for the red color of red beds, typically occur as a coating on the grains of sediments comprising red beds. Classic examples of red beds are the Permian and Triassic strata of the western United States and the Devonian Old Red Sandstone facies of Europe. Primary red beds Primary red beds may be formed by the erosion and redeposition of red soils or older red beds, but a fundamental problem with this hypothesis is the relative scarcity of red-colored source sediments of suitable age close to an area of red-bed sediments in Cheshire, England. Primary red beds may also form by in situ (early diagenetic) redd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basin (geology)
In geology, a depression is a landform sunken or depressed below the surrounding area. Depressions form by various mechanisms. Types Erosion-related: * Blowout: a depression created by wind erosion typically in either a partially vegetated sand dune ecosystem or dry soils (such as a post-glacial loess environment). * Glacial valley: a depression carved by erosion by a glacier. * River valley: a depression carved by fluvial erosion by a river. * Area of subsidence caused by the collapse of an underlying structure, such as sinkholes in karst terrain. * Sink: an endorheic depression generally containing a persistent or intermittent (seasonal) lake, a salt flat (playa) or dry lake, or an ephemeral lake. * Panhole: a shallow depression or basin eroded into flat or gently sloping, cohesive rock.Twidale, C.R., and Bourne, J.A., 2018Rock basins (gnammas) revisited.''Géomorphologie: Relief, Processus, Environnement,'' Vol. 24, No. 2. January 2018. Retrieved 9 June 2020. Collapse- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evaporite
An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments. Formation of evaporite rocks Although all water bodies on the surface and in aquifers contain dissolved salts, the water must evaporate into the atmosphere for the minerals to precipitate. For this to happen, the water body must enter a restricted environment where water input into this environment remains below the net rate of evaporation. This is usually an arid environment with a small basin fed by a limited input of water. When evaporation occurs, the remaining water is enriched in salts, and they precipitate when the water becomes supersaturated. Evaporite depositi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albitization
Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical composition. The minerals which compose the rocks are dissolved and new mineral formations are deposited in their place. Dissolution and deposition occur simultaneously and the rock remains solid. Synonyms to the word metasomatism are metasomatose and metasomatic process. The word metasomatose can also be used as a name for specific varieties of metasomatism (for example '' Mg-metasomatose'' and '' Na-metasomatose''). Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact metamorphic aureole adjacent to an intrusive rock mass. In the metamorphic environment, metasomatism is created by mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcline
Microcline (KAlSi3O8) is an important igneous rock-forming tectosilicate mineral. It is a potassium-rich alkali feldspar. Microcline typically contains minor amounts of sodium. It is common in granite and pegmatites. Microcline forms during slow cooling of orthoclase; it is more stable at lower temperatures than orthoclase. Sanidine is a polymorph of alkali feldspar stable at yet higher temperature. Microcline may be clear, white, pale-yellow, brick-red, or green; it is generally characterized by cross-hatch twinning that forms as a result of the transformation of monoclinic orthoclase into triclinic microcline. The chemical compound name is potassium aluminium silicate, and it is known as E number reference E555. Geology Microcline may be chemically the same as monoclinic orthoclase, but because it belongs to the triclinic crystal system, the prism angle is slightly less than right angles; hence the name "microcline" from the Greek "small slope." It is a fully ordered triclin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Feldspar
Feldspars are a group of rock-forming aluminium tectosilicate minerals, also containing other cations such as sodium, calcium, potassium, or barium. The most common members of the feldspar group are the ''plagioclase'' (sodium-calcium) feldspars and the ''alkali'' (potassium-sodium) feldspars. Feldspars make up about 60% of the Earth's crust, and 41% of the Earth's continental crust by weight. Feldspars crystalize from magma as both intrusive and extrusive igneous rocks and are also present in many types of metamorphic rock. Rock formed almost entirely of calcic plagioclase feldspar is known as anorthosite. Feldspars are also found in many types of sedimentary rocks. Compositions The feldspar group of minerals consists of tectosilicates, silicate minerals in which silicon ions are linked by shared oxygen ions to form a three-dimensional network. Compositions of major elements in common feldspars can be expressed in terms of three endmembers: * potassium feldspar (K-spar) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkosic
Arkose () or arkosic sandstone is a detrital sedimentary rock, specifically a type of sandstone containing at least 25% feldspar. Arkosic sand is sand that is similarly rich in feldspar, and thus the potential precursor of arkose. Quartz is commonly the dominant mineral component, and some mica is often present. Apart from the mineral content, rock fragments may also be a significant component. Arkose usually contains small amounts of calcite cement, which causes it to effervesce (fizz) slightly in dilute hydrochloric acid; sometimes the cement also contains iron oxide. Arkose is typically grey to reddish in colour. The sand grains making up an arkose may range from fine to very coarse, but tend toward the coarser end of the scale. Fossils are rare in arkose, due to the depositional processes that form it, although bedding is frequently visible. Arkose is generally formed from the weathering of feldspar-rich igneous or metamorphic, most commonly granitic, rocks, which are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aeolian Processes
Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials and are effective agents in regions with sparse vegetation, a lack of soil moisture and a large supply of unconsolidated sediments. Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts. The term is derived from the name of the Greek god Aeolus, the keeper of the winds. Definition and setting ''Aeolian processes'' are those processes of erosion, transport, and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as ''aeolian''. Aeolian processes are most important in areas where there is little or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeso Formation
The Yeso Group is a group of geologic formations in New Mexico. It contains fossils characteristic of the Kungurian Age of the early Permian Period. Description The Yeso Group is lithologically complex, ranging from marine shelf carbonate rock to the south through shoreline and sabkha beds to eolian dune and sheet sand deposits to the north. It is exposed in the mountains and other uplifts bordering the Rio Grande Rift and in the Pecos River valley. It is present in the subsurface in the Raton Basin. The group records a major marine transgression from the south during the early Leonardian (Kungurian). In the Jemez Mountains, the group consists of massive cross-bedded lower beds (De Chelly Sandstone) and thinner upper beds (San Ysidro Formation) suggesting a more fluvial depositional environment. The Yeso Group is exposed extensively in the Jemez Mountains, but pinches out in the northern Jemez, delineating the northern limit of the dune field from which it arose. Fart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Raton Basin
Raton or Ratón (Spanish for "mouse") may refer to: Places: * Raton Basin, a geologic structural basin in southern Colorado and northern New Mexico * Raton, New Mexico, the county seat of Colfax County, New Mexico ** Raton Downtown Historic District, a Registered Historic District in Raton, New Mexico * Raton Pass, a mountain pass that is a National Historic Landmark * Ráton, the Hungarian name for Ratin village, Crasna, Sălaj, Romania Other uses: * Ratón (2001-2013), a Spanish fighting bull * , a submarine * ''Raton'', the French name of a character in Fontaine's fable The Monkey and the Cat The Monkey and the Cat is best known as a fable adapted by Jean de La Fontaine under the title ''Le Singe et le Chat'' that appeared in the second collection of his ''Fables'' in 1679 (IX.17). Although there is no evidence that the story existed ... See also * El Ratón (other) {{Disambig, geo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Grande Rift
The Rio Grande rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. The rift extends from central Colorado in the north to the state of Chihuahua, Mexico, in the south. The rift zone consists of four basins that have an average width of . The rift can be observed on location at Rio Grande National Forest, White Sands National Park, Santa Fe National Forest, and Cibola National Forest, among other locations. The Rio Grande rift has been an important site for humans for a long time, because it provides a north–south route that follows a major river. The Rio Grande follows the course of the rift from southern Colorado to El Paso, where it turns southeast and flows toward the Gulf of Mexico. Important cities, including Albuquerque, Santa Fe, Taos, Española, Las Cruces, El Paso, and Ciudad Juárez, lie within the rift. Geology The Rio Grande rift represents the easternmost ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
