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Santa Fe Group (geology)
The Santa Fe Group is a group of geologic formations in New Mexico and Colorado. It contains fossils characteristic of the Oligocene through Pleistocene epochs. The group consists of basin-filling sedimentary and volcanic rocks of the Rio Grande rift, and contains important regional aquifers. Description The Santa Fe Group is widely defined as basin-filling sedimentary and volcanic rocks of the Rio Grande rift. These range in age from late Oligocene to Pleistocene. The oldest formations in the group correspond to the earliest structural deformation associated with rifting. Geologic uplift of the region around the rift has ended deposition, and erosion in the Rio Grande river system has exposed many of the beds deposited earlier, often spectacularly, as in the badlands north of Santa Fe. The formations in the group are divided into lower and upper sections. The lower Santa Fe Group was deposited in bolsons (closed arid basins) where streams drained into intermittent play ... [...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] |
Sedimentary Rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles to settle in place. The particles that form a sedimentary rock are called sediment, and may be composed of geological detritus (minerals) or biological detritus (organic matter). The geological detritus originated from weathering and erosion of existing rocks, or from the solidification of molten lava blobs erupted by volcanoes. The geological detritus is transported to the place of deposition by water, wind, ice or mass movement, which are called agents of denudation. Biological detritus was formed by bodies and parts (mainly shells) of dead aquatic organisms, as well as their fecal mass, suspended in water and slowly piling up on the floor of water bodies (marine snow). Sedimentation may also occur as dissolved minerals precipitate from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alamosa Formation
The Alamosa Formation is a geologic formation in Colorado. It preserves fossils. The formation was deposited by Lake Alamosa, a paleolake that existed from the Pliocene to the middle Pleistocene. See also * List of fossiliferous stratigraphic units in Colorado * Paleontology in Colorado The location of the state of Colorado Paleontology in Colorado refers to paleontological research occurring within or conducted by people from the U.S. state of Colorado. The geologic column of Colorado spans about one third of Earth's history. ... References Geologic formations of Colorado {{Colorado-geologic-formation-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Integrated Drainage
In geomorphology, drainage systems, also known as river systems, are the patterns formed by the streams, rivers, and lakes in a particular drainage basin. They are governed by the topography of land, whether a particular region is dominated by hard or soft rocks, and the gradient of the land. Geomorphologists and hydrologists often view streams as part of drainage basins (and sub-basins). This is the topographic region from which a stream receives runoff, throughflow, and its saturated equivalent, groundwater flow. The number, size, and shape of the drainage basins varies and the larger and more detailed the topographic map, the more information is available. Drainage patterns Per the lie of channels, drainage systems can fall into one of several categories, known as drainage patterns. These depend on the topography and geology of the land. All forms of transitions can occur between parallel, dendritic, and trellis patterns. Accordant versus discordant drainage patterns A drai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foothills
Foothills or piedmont are geographically defined as gradual increases in elevation at the base of a mountain range, higher hill range or an upland area. They are a transition zone between plains and low relief hills and the adjacent topographically higher mountains, hills, and uplands. Frequently foothills consist of alluvial fans, coalesced alluvial fans, and dissected plateaus. Description Foothills primarily border mountains, especially those which are reached through low ridges that increase in size closer and closer to the mountain, but can also border uplands and higher hills. Examples Areas where foothills exist, or areas commonly referred to as the foothills, include the: *Sierra Nevada foothills of California, USA *Foothills of the San Gabriel Valley in Los Angeles County, California, USA *Rocky Mountain Foothills in British Columbia and Alberta, Canada *Silesian Foothills in Silesia, Poland *Sivalik Hills along the Himalayas in the Indian subcontinent * Catalin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Playa Lake
Playa (plural playas) may refer to: Landforms * Endorheic basin, also known as a sink, alkali flat or sabkha, a desert basin with no outlet which periodically fills with water to form a temporary lake * Dry lake, often called a ''playa'' in the southwestern United States Populated places United States * Playas, New Mexico, an unincorporated community in New Mexico * Playa, Añasco, Puerto Rico, a barrio in the municipality of Añasco, Puerto Rico * Playa, Guayanilla, Puerto Rico, a barrio in the municipality of Guayanilla, Puerto Rico * Playa, Ponce, Puerto Rico, a barrio of Ponce, Puerto Rico * Playa, Santa Isabel, Puerto Rico, a barrio in the municipality of Santa Isabel, Puerto Rico * Playa, Yabucoa, Puerto Rico, a barrio in the municipality of Yabucoa, Puerto Rico Cuba * Playa, Havana, one of the 15 municipalities of the City of Havana, Cuba Ecuador * Playas Canton, Ecuador ** Playas, Ecuador, the administrative center of the Playas Canton Other * The Playa, Black Rock Des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolson
A bolson is a desert valley or Depression (geology), depression, usually draining into a Sink (geography), playa or salt pan, and entirely surrounded by recently Geologic uplift, uplifted hills or mountains. Bolsons are sites of active deposition of sediments (aggradation).* They are a type of endorheic basin characteristic of basin and range topography. The term was an American English, Americanism originating in the 1830s and 1840s during the explorations of the far west of North America, particularly of what became the Southwestern United States and northern Mexico. It was derived from the Spanish language, Spanish ''bolsón'', (large purse). bolson from www.britannica.com accessed July 29, 2018 Examples of this type of formation would be the Hueco Bolson in the western Trans-Pecos of Texas, and the Mesilla Bolson in southern New Mexico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Badlands
Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in ''Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, minimal vegetation, lack of a substantial regolith, and high drainage density.A.J. Parsons and A.D. Abrahams, Editors (2009) ''Geomorphology of Desert Environments'' (2nd ed.) Springer Science & Business Media Ravines, gullies, buttes, hoodoos and other such geologic forms are common in badlands. Badlands are found on every continent except Antarctica, being most common where there are unconsolidated sediments. They are often difficult to navigate by foot, and are unsuitable for agriculture. Most are a result of natural processes, but destruction of vegetation by overgrazing or pollution can produce anthropogenic badlands. Badlands topography Badlands are characterized by a distinctive badlands topography. This is terrain in which w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio Grande
The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio Grande is . It originates in south-central Colorado, in the United States, and flows to the Gulf of Mexico. The Rio Grande drainage basin (watershed) has an area of ; however, the endorheic basins that are adjacent to and within the greater drainage basin of the Rio Grande increase the total drainage-basin area to . The Rio Grande with Rio Grande Valley (landform), its fertile valley, along with its tributaries, is a vital watersource for seven US and Mexican states, and flows primarily through arid and semi-arid lands. After traversing the length of New Mexico, the Rio Grande becomes the Mexico–United States border, between the U.S. state of Texas and the northern Mexican states of Chihuahua (state), Chihuahua and Coahuila, Nuevo León a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distinct from weathering which involves no movement. Removal of rock or soil as clastic sediment is referred to as ''physical'' or ''mechanical'' erosion; this contrasts with ''chemical'' erosion, where soil or rock material is removed from an area by dissolution. Eroded sediment or solutes may be transported just a few millimetres, or for thousands of kilometres. Agents of erosion include rainfall; bedrock wear in rivers; coastal erosion by the sea and waves; glacial plucking, abrasion, and scour; areal flooding; wind abrasion; groundwater processes; and mass movement processes in steep landscapes like landslides and debris flows. The rates at which such processes act control how fast a surface is eroded. Typically, physical erosion procee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geologic Uplift
Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted to form one or more mountain ranges. This involves a series of geological processes collectively called orogenesis. These include both structural deformation of existing continental crust and the creation of new continental crust through volcanism. Magma rising in the orogen carries less dense material upwards while leaving more dense material behind, resulting in compositional differentiation of Earth's lithosphere ( crust and uppermost mantle). A synorogenic process or event is one that occurs during an orogeny. The word "orogeny" () comes from Ancient Greek (, , + , , ). Although it was used before him, the term was employed by the American geologist G. K. Gilbert in 1890 to describe the process of mountain-building as distinguished f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rifting
In geology, a rift is a linear zone where the lithosphere is being pulled apart and is an example of extensional tectonics. Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts mainly on one side. Where rifts remain above sea level they form a rift valley, which may be filled by water forming a rift lake. The axis of the rift area may contain volcanic rocks, and active volcanism is a part of many, but not all, active rift systems. Major rifts occur along the central axis of most mid-ocean ridges, where new oceanic crust and lithosphere is created along a divergent boundary between two tectonic plates. ''Failed rifts'' are the result of continental rifting that failed to continue to the point of break-up. Typically the transition from rifting to spreading develops at a triple junction where three converging rifts meet over a hotspot. Two of these evolve to the poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
