|
Molas Formation
The Molas Formation is a geologic formation that is found in the Four Corners region of the United States. Its age is poorly constrained but is thought to be Namurian (late Mississippian to middle Pennsylvanian). Description The Molas Formation is a sequence of continental red beds. It is divided into three members. The lowermost Coalbank Hill Member is up to of purplish-red to reddish-brown siltstone and conglomerate. This is overlain by an informal middle member, consisting of mudrock, sandstone, and conglomerate, that is typically around . The upper member is typically around that includes maroon to light gray sandstone. The upper member grades into the overlying Pinkerton Trail Formation. The Coalbank Hill Member may be a terra rossa (a residual soil formed by weathering of the underlying Leadville Limestone) and may correlate with the Log Springs Formation in the Jemez Mountains of New Mexico. It has also been interpreted as a loess trapped on the karst surface ... [...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] |
Terra Rossa
Terra rossa (Italian for "red soil") is a well-drained, reddish, clayey to silty soil with neutral pH conditions and is typical of the Mediterranean region. The reddish color of terra rossa is the result of the preferential formation of hematite over goethite. This soil type typically occurs as a discontinuous layer that ranges from a few centimeters to several meters in thickness that covers limestone and dolomite bedrock in karst regions. The high internal drainage and neutral pH conditions of terra rossa are a result of the karstic nature of the underlying limestone and dolomite.Torrent, J., 2005. ''Mediterranean soils.'' In: Hillel, D. (Ed.), ''Encyclopaedia of Soils in the Environment,'' vol. 2. Elsevier Academic Press, Oxford, pp. 418–427.Merino, E., Banerjee, A. and Dworkin, S., 2006. ''Dust, terra rossa, replacement, and karst: serendipitous geodynamics in the critical zone.'' ''Geochimica et Cosmochimica Acta,'' 70(18), p. A416.Vingiani, S., Di Iorio, E., Colombo, C. an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mosquito Range
The Mosquito Range (elevation approximately 14,000 ft) is a high mountain range in the Rocky Mountains of central Colorado in the United States. The peaks of the range form a ridge running north–south for roughly 40 mi (64 km) from southern Summit County on the north end, then along the boundary between Lake and Park Counties. The ranges forms a high barrier separating the headwaters of the Arkansas River near Leadville from South Park and the headwaters of the South Platte River near Fairplay. The highest peak in the range is Mount Lincoln at an elevation of 14,286 ft. Other fourteeners in the range are Quandary Peak (14,272 ft), Mount Bross (14,172 ft), Mount Democrat (14,148 ft), and Mount Sherman (14,036 ft). Geology The mountains are faulted anticlines formed as part of the Sawatch Uplift during the Laramide orogeny around 65 million years ago (Mya). The mountains were originally contiguous with the higher Sawatch Range to the we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sangre De Cristo Mountains
) , country= United States , subdivision1_type= States , subdivision1= , parent= Rocky Mountains , geology= , orogeny= , area_mi2= 17193 , range_coordinates= , length_mi= 242 , length_orientation= north-south , width_mi= 120 , width_orientation= east-west , highest= Blanca Peak , elevation_ft= 14351 , coordinates= , highest_location= East of Alamosa, Colorado , map= , map_size= , map_caption= The Sangre de Cristo Mountains (Spanish for "Blood of Christ") are the southernmost subrange of the Rocky Mountains. They are located in southern Colorado and northern New Mexico in the United States. The mountains run from Poncha Pass in South-Central Colorado, trending southeast and south, ending at Glorieta Pass, southeast of Santa Fe, New Mexico. The mountains contain a number of fourteen thousand foot peaks in the Colorado portion, as well as all the peaks in New Mexico which are over twelve thousand feet. The name of the mountains may refer to the occasion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Juan Mountains
The San Juan Mountains is a high and rugged mountain range in the Rocky Mountains in southwestern Colorado and northwestern New Mexico. The area is highly mineralized (the Colorado Mineral Belt) and figured in the gold and silver mining industry of early Colorado. Major towns, all old mining camps, include Creede, Lake City, Silverton, Ouray, and Telluride. Large scale mining has ended in the region, although independent prospectors still work claims throughout the range. The last large scale mines were the Sunnyside Mine near Silverton, which operated until late in the 20th century and the Idarado Mine on Red Mountain Pass that closed down in the 1970s. Famous old San Juan mines include the Camp Bird and Smuggler Union mines, both located between Telluride and Ouray. The Summitville mine was the scene of a major environmental disaster in the 1990s when the liner of a cyanide-laced tailing pond began leaking heavily. Summitville is in the Summitville caldera, one of m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illite
Illite is a group of closely related non-expanding clay minerals. Illite is a secondary mineral precipitate, and an example of a phyllosilicate, or layered alumino-silicate. Its structure is a 2:1 sandwich of silica tetrahedron (T) – alumina octahedron (O) – silica tetrahedron (T) layers. The space between this T-O-T sequence of layers is occupied by poorly hydrated potassium cations which are responsible for the absence of swelling. Structurally, illite is quite similar to muscovite with slightly more silicon, magnesium, iron, and water and slightly less tetrahedral aluminium and interlayer potassium. The chemical formula is given as , but there is considerable ion (isomorphic) substitution. It occurs as aggregates of small monoclinic grey to white crystals. Due to the small size, positive identification usually requires x-ray diffraction or SEM-EDS ( automated mineralogy) analysis. Illite occurs as an altered product of muscovite and feldspar in weathering and hydrothermal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaolinite
Kaolinite ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral sheet of alumina () octahedra. Rocks that are rich in kaolinite are known as kaolin () or china clay. Kaolin is occasionally referred to by the antiquated term lithomarge, from the Ancient Greek ''litho-'' and Latin ''marga'', meaning 'stone of marl'. Presently the name lithomarge can refer to a compacted, massive form of kaolin. The name ''kaolin'' is derived from Gaoling (), a Chinese village near Jingdezhen in southeastern China's Jiangxi Province. The name entered English in 1727 from the French version of the word: , following François Xavier d'Entrecolles's reports on the making of Jingdezhen porcelain. Kaolinite has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g). It is a soft, earthy, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karst
Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant rocks, such as quartzite, given the right conditions. Subterranean drainage may limit surface water, with few to no rivers or lakes. However, in regions where the dissolved bedrock is covered (perhaps by debris) or confined by one or more superimposed non-soluble rock strata, distinctive karst features may occur only at subsurface levels and can be totally missing above ground. The study of ''paleokarst'' (buried karst in the stratigraphic column) is important in petroleum geology because as much as 50% of the world's hydrocarbon reserves are hosted in carbonate rock, and much of this is found in porous karst systems. Etymology The English word ''karst'' was borrowed from German in the late 19th century, which entered German much earlier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loess
Loess (, ; from german: Löss ) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of Earth's land area is covered by loess or similar deposits. Loess is a periglacial or aeolian (windborne) sediment, defined as an accumulation of 20% or less of clay and a balance of roughly equal parts sand and silt (with a typical grain size from 20 to 50 micrometers), often loosely cemented by calcium carbonate. It is usually homogeneous and highly porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical bluffs. Properties Loess is homogeneous, porous, friable, pale yellow or buff, slightly coherent, typically non- stratified and often calcareous. Loess grains are angular, with little polishing or rounding, and composed of crystals of quartz, feldspar, mica and other minerals. Loess can be described as a rich, dust-like soil. Loess deposits may become very thick, more than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Mexico
) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Keres, Zuni , Governor = , Lieutenant Governor = , Legislature = New Mexico Legislature , Upperhouse = Senate , Lowerhouse = House of Representatives , Judiciary = New Mexico Supreme Court , Senators = * * , Representative = * * * , postal_code = NM , TradAbbreviation = N.M., N.Mex. , area_rank = 5th , area_total_sq_mi = 121,591 , area_total_km2 = 314,915 , area_land_sq_mi = 121,298 , area_land_km2 = 314,161 , area_water_sq_mi = 292 , area_water_km2 = 757 , area_water_percent = 0.24 , population_as_of = 2020 , population_rank = 36th , 2010Pop = 2,117,522 , population_density_rank = 45th , 2000DensityUS = 17.2 , 2000Density = 6.62 , MedianHouseholdIncome = $51,945 , IncomeRank = 45th , AdmittanceOrder = ... [...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] |
.jpg "Click for more on -> Karst")
