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San Ysidro Member
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] |
Group (stratigraphy)
In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into supergroups. Groups are useful for showing relationships between formations, and they are also useful for small-scale mapping or for studying the stratigraphy of large regions. Geologists exploring a new area have sometimes defined groups when they believe the strata within the groups can be divided into formations during subsequent investigations of the area. It is possible for only some of the strata making up a group to be divided into formations. An example of a group is the Glen Canyon Group, which includes (in ascending order) the Wingate Sandstone, the Moenave Formation, the Kayenta Formation, and the Navajo Sandstone. Each of the formations can be distinguished from its neighbor by its lithology, but all were deposited in the same vast ... [...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] |
Gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. Alabaster, a fine-grained white or lightly tinted variety of gypsum, has been used for sculpture by many cultures including Ancient Egypt, Mesopotamia, Ancient Rome, the Byzantine Empire, and the Nottingham alabasters of Medieval England. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison. Etymology and history The word ''gypsum'' is derived from the Greek word (), "plaster". Because the quarries of the Montmartre district of Paris have long furnished burnt gypsum (calcined gypsum) used for various purposes, this dehydrated gypsum became known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Vallos 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] |
Arroyo De Alamillo 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] |
San Ysidro 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] |
De Chelly Sandstone
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] |
Cross-bedding
In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original depositional layering is tilted, such tilting not being the result of post-depositional deformation. Cross-beds or "sets" are the groups of inclined layers, which are known as cross-strata. Cross-bedding forms during deposition on the inclined surfaces of bedforms such as ripples and dunes; it indicates that the depositional environment contained a flowing medium (typically water or wind). Examples of these bedforms are ripples, dunes, anti-dunes, sand waves, hummocks, bars, and delta slopes.Collinson, J.D., Thompson, D.B., 1989, Sedimentary Structures (2nd ed): Academic Division of Unwin Hyman Ltd, Winchester, MA, XXX p. Environments in which water movement is fast enough and deep enough to develop large-scale bed forms fall into thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jemez Mountains
The Jemez Mountains are a group of mountains in Rio Arriba, Sandoval, and Los Alamos counties, New Mexico, United States. Numerous Puebloan Indian tribes have lived in the Jemez Mountains region since before the Spanish arrived in New Mexico. The Pueblo Indians of this region are the Towa-speaking Jemez people for which this mountain range is named, the Keres-speaking Keresan Indians, and the Tewa-speaking Tewa Indians. Tsąmpiye'ip'įn is the Tewa language name for the Jemez Mountains. The highest point in the range is Chicoma Mountain (also spelled as Tschicoma or Tchicoma) at an elevation of . The town of Los Alamos and the Los Alamos National Laboratory adjoin the eastern side of the range while the town of Jemez Springs is to the west. Pajarito Mountain Ski Area is the only ski area in the Jemez. New Mexico State Highway 4 is the primary road that provides vehicular access to locations in the Jemez Mountains. Geology The Jemez Mountains lie to the north of the Alb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yeso Group
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] |
Leonardian
In the geologic timescale, the Kungurian is an age or stage of the Permian. It is the latest or upper of four subdivisions of the Cisuralian Epoch or Series. The Kungurian lasted between and million years ago (Ma). It was preceded by the Artinskian and followed by the Roadian. It corresponds roughly to the Leonardian Stage, covering the span from 280 to 270.6 ± 0.7 Ma in the North American system. Stratigraphy The Kungurian is named after the Russian city of Kungur in Perm Krai. The stage was introduced into scientific literature by Russian geologist Alexandr Antonovich Stukenberg (Alexander Stuckenberg) in 1890.; 2002: ''Progress report on the base of the Artinskian and base of the Kungurian by the Cisuralian Working Group'', Permophiles 41: pp 13–16. The base of the Kungurian Stage is defined as the place in the stratigraphic record where fossils of conodont species ''Neostreptognathodus pnevi'' and ''Neostreptognathodus exculptus'' first appear. As of 2009, ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transgression (geology)
A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground, which results in flooding. Transgressions can be caused by the land sinking or by the ocean basins filling with water or decreasing in capacity. Transgressions and regressions may be caused by tectonic events such as orogenies, severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load. During the Cretaceous, seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin. That reduced the world's ocean basin capacity and caused a rise in sea level worldwide. As a result of the sea level rise, the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean. The opposite of transgression is regression in which the sea level falls relative to the land and expo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
