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McRae Group
The McRae Group is a geological Group (stratigraphy), group exposed in southern New Mexico whose strata, including layers of the Hall Lake Formation and Jose Creek Formation, date to the Late Cretaceous. Dinosaur remains are among the fossils that have been recovered from this unit. Description The group consists of a basal conglomerate (geology), conglomerate interbedded with shale and siltstone and a sequence of alternating sandstone and shale. The lower conglomerates contain volcanic debris, while the upper beds contain sparse nonvolcanic rock fragments. The shales are reddish brown to purplish while the sandstones are light gray. The sandstones are medium bedded to massive and sometimes form Hogback (geology), hogbacks. The total thickness is in excess of . The group is present around Elephant Butte Reservoir, in the Caballo Mountains, and under much of the Jornada del Muerto. It overlies the Mesaverde Group, from which it Provenance (geology), derives much of its sediments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geological Formation
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] |
Siltstone
Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility. Although its permeability and porosity is relatively low, siltstone is sometimes a tight gas reservoir rock, an unconventional reservoir for natural gas that requires hydraulic fracturing for economic gas production. Siltstone was prized in ancient Egypt for manufacturing statuary and cosmetic palettes. The siltstone quarried at Wadi Hammamat was a hard, fine-grained siltstone that resisted flaking and was almost ideal for such uses. Description There is not complete agreement on the definition of siltstone. One definition is that siltstone is mudrock (clastic sedimentary rock containing at least 50% clay and silt) in which at least 2/3 of the clay and silt fraction is composed of silt-sized particles. Silt is defined as grains 2–62 μm in diam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canna (plant)
''Canna'' or canna lily is a genus of flowering plants consisting of 10 species. It is the only genus in the family Cannaceae.The Cannaceae of the World, Hiltje Maas-van de Kamer, H. Maas-van der Kamer & Paulus Johannes Maria Maas, P.J.M. Maas, BLUMEA 53: 247–318 All of the genus's species are native to the Neotropical realm, American tropicsLamarck, Jean-Baptiste. ''Botanical Encyclelopédie''. and were naturalized in Europe, India and Africa in the 1860s.Chaté, E. (1867).'' Le Canna, son histoire, sa culture. ''Libraire Centrale d'Agriculture et de Jardinage Although they grow native to the tropics, most cultivars have been developed in temperateness, temperate climates and are easy to grow in most countries of the world, as long as they receive at least 6–8 hours average sunlight during the summer, and are moved to a warm location for the winter. See the Canna (Plant) Gallery, ''Canna'' cultivar gallery for photographs of ''Canna'' cultivars. Cannas are not true lili ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geinitzia (plant)
''Geinitzia'' is an extinct genus of conifers, with an uncertain position within the group. Species belonging to the genus lived in the late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ... and have been found in ArgentinaC. Álvarez-Ramis, M. Prámparo, and O. H. Papú. 2004. Estudio preliminar de paleofloras cretácicas procedentes de la base de la Formación Loncoche (Mendoza, Argentina). ''Coloquios de Paleontología'' 54:7-14 and Europe. Species A number of species have been described in ''Geinitzia''. :''Geinitzia cretacea'' :''Geinitzia formosa'' :''Geinitzia reichenbachii'' :''Geinitzia schlotheimii'' References Cretaceous plants Pinales Prehistoric gymnosperm genera {{cretaceous-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
The Paleocene ( ), or Palaeocene, is a geological epoch (geology), epoch that lasted from about 66 to 56 mya (unit), million years ago (mya). It is the first epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism (Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breccia
Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, fault (geology), fault or tectonics, tectonic breccia, igneous breccia, Impact event, impact breccia, and Hydrothermal circulation, hydrothermal breccia. A megabreccia is a breccia composed of very large rock fragments, sometimes kilometers across, which can be formed by landslides, impact events, or caldera collapse. Types Breccia is composed of coarse rock fragments held together by cement or a fine-grained matrix. Like Conglomerate (geology), conglomerate, breccia contains at least 30 percent of gravel-sized particles (particles over 2mm in size), but it is distinguished from Conglomerate (geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alluvial Fan
An alluvial fan is an accumulation of sediments that fans outwards from a concentrated source of sediments, such as a narrow canyon emerging from an escarpment. They are characteristic of mountainous terrain in arid to Semi-arid climate, semiarid climates, but are also found in more humid environments subject to intense rainfall and in areas of modern glaciation. They range in area from less than to almost . Alluvial fans typically form where a flow of sediment or rocks emerge from a confined channel and are suddenly free to spread out in many directions. For example, many alluvial fans form when steep mountain valleys meet a flat plain. The transition from a narrow channel to a wide open area reduces the carrying capacity of flow and results in Deposition (geology), deposition of sediments. The flow can take the form of infrequent debris flows like in a landslide, or can be carried by an intermittent stream or creek. The reduction of flow is key to the formation of alluvial ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mudflow
A mudflow, also known as mudslide or mud flow, is a form of mass wasting involving fast-moving flow of debris and dirt that has become liquified by the addition of water. Such flows can move at speeds ranging from 3 meters/minute to 5 meters/second. Mudflows contain a significant proportion of clay, which makes them more fluid than debris flows, allowing them to travel farther and across lower slope angles. Both types of flow are generally mixtures of particles with a wide range of sizes, which typically become sorted by size upon deposition. Mudflows are often called mudslips, a term applied indiscriminately by the mass media to a variety of mass wasting events. Mudflows often start as slides, becoming flows as water is entrained along the flow path; such events are often called mud failures. Other types of mudflows include lahars (involving fine-grained pyroclastic deposits on the flanks of volcanoes) and jökulhlaups (outbursts from under glaciers or icecaps). A statutory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Provenance (geology)
Provenance, also known as geographic attribution, in geology refers to the origins or sources of particles within sediment and Sedimentary rock, sedimentary rocks. Metamorphic rock, Metamorphic and igneous rock, igneous rocks are broken down via weathering and erosion into sediment as part of the rock cycle. These sediments are transported by wind, water, ice, or gravity, before being deposited in horizontal layers. As more sediment is deposited over time, earlier layers are covered and compacted. Finally, they are cemented to form a new rock. Modern geological provenance research specifically refers to the application of compositional analyses to determine sedimental origins. This is often used in conjunction with the study of exhumation histories, forward-modeling of paleo-earth systems, and interpretation of drainage networks and their evolution. In combination, these help to characterize the "source to sink" journey of Clastic rock, clastic sediments from the hinterland to a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jornada Del Muerto
Jornada del Muerto was the name given by the Spanish conquistadors to the Jornada del Muerto desert Endorheic basin, basin, and the almost waterless trail across the Jornada beginning north of Las Cruces, New Mexico, Las Cruces and ending south of Socorro, New Mexico. The name translates from Spanish language, Spanish as "Dead Man's Journey" or "Route of the Dead Man". The trail was part of the Camino Real de Tierra Adentro which led northward from central colonial New Spain, present-day Mexico, to the farthest reaches of the viceroyalty in northern Santa Fe de Nuevo México, Nuevo México Province (the area around the upper valley of the Rio Grande). Spaceport America is located in the middle portion of the Jornada del Muerto at an elevation of . The Trinity (nuclear test), Trinity nuclear test site, the location of the first test of an atomic bomb in 1945 is in the northern portion of the Jornada. Natural history The Jornada del Muerto basin is wide east to west and from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caballo Mountains
The Caballo Mountains, (Spanish: "horse") are a mountain range located in Sierra and Doña Ana Counties, New Mexico, United States. The range is located east of the Rio Grande and Caballo Lake, and west of the Jornada del Muerto; the south of the range extends into northwest Doña Ana County. The nearest towns are Truth or Consequences and Hatch. Most of the Caballo Mountains are located on land owned by the Bureau of Land Management. The mountains are unusual, and perhaps unique in New Mexico, for the relatively complete geologic history revealed by their rocks. Vehicular access to the range is by Interstate 25 from the west, by New Mexico State Road 51 from the north, and by several dirt roads from the east. Geography The Caballo Mountains trend north and south, with a length of approximately 32 miles (50 km). The width of the range varies from 3–6 miles (5–10 km). The highest point on the range, Timber Mountain (7,565 feet), has a topographic prominen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
