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Ritito Conglomerate
The Ritito Conglomerate is a Formation (geology), geologic formation in northern New Mexico dating to the Oligocene Epoch (geology), epoch. Description The formation is composed of orange-pink to reddish-brown arkosic Conglomerate (geology), conglomerate, sandstone, and siltstone with muscovite. The Matrix (geology), matrix is gray to tan except near Abiquiu, where it has a distinct red-brown color. Clasts are angular to well-rounded and are mostly of pebble size, but range from granules to boulders. The clasts are 44% Proterozoic quartzite, with 25% granite, 13% metavolcanic rock, 10% quartz, 5% schist, and 3% gneiss, with traces of chert and Phanerozoic sandstone. Some of the clasts have been identified as reddish-brown quartzite from the Cerro Colorado area or quartzite of the Ortega Formation. Imbrication (sedimentology), Imbrication indicates deposition in a meandering southward-flowing river system. The formation crops out in a broad area between the northern Jemez Mounta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also borders the state of Texas to the east and southeast, Oklahoma to the northeast, and shares Mexico-United States border, an international border with the Mexican states of Chihuahua (state), Chihuahua and Sonora to the south. New Mexico's largest city is Albuquerque, and its List of capitals in the United States, state capital is Santa Fe, New Mexico, Santa Fe, the oldest state capital in the U.S., founded in 1610 as the government seat of Santa Fe de Nuevo México, Nuevo México in New Spain. It also has the highest elevation of any state capital, at . New Mexico is the List of U.S. states and territories by area, fifth-largest of the fifty states by area, but with just over 2.1 million residents, ranks List of U.S. states and terri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clasts
Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks by physical weathering.Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-5 Geologists use the term clastic to refer to sedimentary rocks and particles in sediment transport, whether in suspension or as bed load, and in sediment deposits. Sedimentary clastic rocks Clastic sedimentary rocks are rocks composed predominantly of broken pieces or ''clasts'' of older weathered and eroded rocks. Clastic sediments or sedimentary rocks are classified based on grain size, clast and cementing material (matrix) composition, and texture. The classification factors are often useful in determining a sample's environment of deposition. An example of clastic environment would be a river system in which the full range of grains being transported by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tusas Mountains
The Tusas Mountains are a mountain range in northern New Mexico, extending slightly into southern Colorado. They are considered the southeasternmost part of the San Juan Mountains. Grouse Mesa, , is the highest peak in the range. The mountains are located to the west of Taos and northwest of Santa Fe. The Tusas Mountains are a wide region of upland mesas and gently sloping mountains, dissected in places by deep canyons. Geography The eastern part of the range is primarily located in the Carson National Forest, bordered by the Taos Plateau volcanic field and Rio Grande del Norte National Monument to the east. It provides the headwaters for the Rio San Antonio, a tributary of the Conejos River (which flows into the Rio Grande in Colorado), and further south the Rio Tusas and Rio Vallecito, which form the Rio Ojo Caliente, a tributary of the Rio Chama (also a Rio Grande tributary). Numerous volcanic features are located along the eastern edge of the range bordering the Taos platea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jemez Mountains
The Jemez Mountains (, Tewa: ''Tsąmpiye'ip'įn'', Navajo: ''Dził Łizhinii'') 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 for centuries before the Spanish arrived in New Mexico. The Pueblo Nations of this region are the Towa-speaking Jemez people, after whom the mountain range is named, and the Keres-speaking Zia People. Pueblos in the Jemez Mountains of New Mexico consisted of compact multistoried buildings which enclosed small plazas. Most of their several hundred rooms were probably occupied by single families, but some were storerooms. The Jemez Mountains include climates varying from desert at the lowest elevations to sub-arctic conditions at the highest elevations. A significant diversity of climate and vegetation is linked to gradients in elevation and the region's topographical features. The highest point in the range is Chicoma Moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imbrication (sedimentology)
In sedimentology, imbrication is a primary depositional Fabric (geology), fabric consisting of a preferred orientation of clasts such that they overlap one another in a consistent fashion, rather like a run of toppled dominoes. Imbrication is observed in Conglomerate (geology), conglomerates and in some volcaniclastic deposits. Types : In conglomerates the shape of many clasts can be approximated to an ellipsoid, with a long axis (A), an intermediate axis (B) and a short axis (C). * ''A-axis imbrication'' where the long axes of the clasts are oriented parallel to the flow direction. This fabric is characteristic of clasts carried in suspension and this is only preserved in the case of a fast-waning flow in which the clasts are deposited without any significant rolling. This fabric is typical of conglomerates at the base of turbidite beds but is also occasionally observed in alluvial fan deposits reworked by flash floods * ''AB-plane imbrication'' where the long axes of the clast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ortega Formation
The Ortega Formation is a geologic formation that crops out in most of the mountain ranges of northern New Mexico. Detrital zircon geochronology establishes a maximum age for the formation of 1690-1670 million years ( Mya), in the Statherian period of the Precambrian.Jones ''et al.'' 2011 Description The Ortega Formation consists of a very clean (98% modal quartzBauer 2004, p.198), typically bluish-white, quartzite, with some beds near the base of the formation composed of metaconglomerate. Crossbedding is found throughout the formation, and aluminosilicate minerals are abundant within the formation. These show that its lower beds were buried deeply enough to be metamorphosed to the sillimanite facies, at temperatures of over . The Ortega Formation is the principal ridge-forming formation of the Picuris Mountains and is a uniform thick. The contact between the Ortega Formation and the underlying Vadito Group is fairly easy to trace using a regional manganese-rich marker bed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phanerozoic
The Phanerozoic is the current and the latest of the four eon (geology), geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. It is the eon during which abundant animal and plant life has population growth, proliferated, evolutionary radiation, diversified and colonization (biology), colonized various ecological niche, niches on the Earth's surface, beginning with the Cambrian period when animals first developed hard shells that can be clearly preserved in the fossil record. The time before the Phanerozoic, collectively called the ''Precambrian'', is now divided into the Hadean, Archean, Archaean and Proterozoic eons. The time span of the Phanerozoic starts with the Cambrian Explosion, sudden appearance of fossilised evidence of a number of animal phylum (biology), phyla; the evolution of those phyla into diverse forms; the evolutionary history of plants, evolution of plants; the evolution of fish, arthropods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a precipitation (chemistry), chemical precipitate or a diagenesis, diagenetic replacement, as in petrified wood. Chert is typically composed of the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, Dictyochales, silicoflagellates, and radiolarians. Precambrian cherts are notable for the presence of fossil cyanobacteria. In addition to Micropaleontology, microfossils, chert occasionally contains macrofossils. However, some chert is devoid of any fossils. Chert varies greatly in color, from white to black, but is most often found as gray, brown, grayish brown and light green to rusty redW.L. Roberts, T.J. Campbell, G.R. Rapp Jr., ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gneiss
Gneiss (pronounced ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under pressures ranging from 2 to 15 kbar, sometimes even more, and temperatures over 300 °C (572 °F). Gneiss nearly always shows a banded texture characterized by alternating darker and lighter colored bands and without a distinct Cleavage (geology), cleavage. Gneisses are common in the ancient crust of Continental Shield, continental shields. Some of the oldest rocks on Earth are gneisses, such as the Acasta Gneiss. Description image:Orthogneiss Geopark.jpg, Orthogneiss from the Czech Republic In traditional English and North American usage, a gneiss is a coarse-grained metamorphic rock showing compositional banding (gneissic banding) but poorly developed schistosity and indistinct Cleavage (geology), cleavage. In other words, it i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Schist
Schist ( ) is a medium-grained metamorphic rock generally derived from fine-grained sedimentary rock, like shale. It shows pronounced ''schistosity'' (named for the rock). This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes or plates. This texture (geology), texture reflects a high content of platy minerals, such as mica, talc, chlorite group, chlorite, or graphite. These are often interleaved with more granular minerals, such as feldspar or quartz. Schist typically forms during regional metamorphism accompanying the process of mountain building (orogeny) and usually reflects a medium Metamorphism#Metamorphic grades, grade of metamorphism. Schist can form from many different kinds of rocks, including sedimentary rocks such as mudstones and igneous rocks such as tuffs. Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a ''mica schis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of Silicon dioxide, SiO2. Quartz is, therefore, classified structurally as a Silicate mineral#Tectosilicates, framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classifi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metavolcanic Rock
Metavolcanic rock is volcanic rock that shows signs of having experienced metamorphism. In other words, the rock was originally produced by a volcano, either as lava or tephra. The rock was then subjected to high pressure, high temperature or both, for example by burial under younger rocks, causing the original volcanic rock to recrystallize. Metavolcanic rocks are sometimes described informally as ''metavolcanics''. When it is possible to determine the original volcanic rock type from the properties of the metavolcanic rock (particularly if the degree of metamorphism is slight), the rock is more precisely named by appylying the prefix ''meta-'' to the original rock type. For example, a weakly metamorphosed basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ... would be describe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
