|
Riverside Mountains
The Riverside Mountains are a mountain range in Riverside County, California. The town of Vidal, California is located in the West Riverside Mountains. Geography The Riverside Mountains are in the Colorado Desert, in the Lower Colorado River Valley region. They are southeast of the Turtle Mountains and north of the Big Maria Mountains, and the Colorado River borders its eastern perimeter. The high point of the range is . Riverside Mountains Wilderness The Riverside Mountains Wilderness was established in 1994 and is managed by the Bureau of Land Management. The Colorado River parallels this 24,004 acre wilderness on its eastern edge. The landscape varies from gently sloping bajadas to steep, rugged interiors. Washes emerging from canyons divide the bajadas below. Numerous peaks in the Riverside Mountains give this small range a rough, craggy appearance. Two sensitive plant species, the foxtail cactus and California barrel cactus; and a small herd of Burro deer (''Odocoileus h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Riverside Mountains
The West Riverside Mountains are a mountain range in Riverside County, California. References See also *Riverside Mountains *Parker Valley The Parker Valley is located along the Lower Colorado River within the Lower Colorado River Valley region, in southwestern Arizona and southeastern California. Its natural habitats are within the Sonoran Desert (Arizona) and Colorado Desert (C ... Mountain ranges of Southern California Mountain ranges of Riverside County, California {{RiversideCountyCA-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mule Deer
The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related white-tailed deer (''Odocoileus virginianus''), which is found throughout most of North America east of the Rocky Mountains and in the valleys of the Rocky Mountains from Idaho and Wyoming northward, mule deer are only found on the western Great Plains, in the Rocky Mountains, in the southwest United States, and on the west coast of North America. Mule deer have also been introduced to Argentina and Kauai, Kauai, Hawaii. Taxonomy Mule deer can be divided into two main groups: the mule deer (''sensu stricto'') and the black-tailed deer. The first group includes all subspecies, except ''O. h. columbianus'' and ''Sitka deer, O. h. sitkensis'', which are in the black-tailed deer group. The two main groups have been treated as separate species, but ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jurassic
The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Core Complex
Metamorphic core complexes are exposures of deep crust exhumed in association with largely amagmatic extension. They form, and are exhumed, through relatively fast transport of middle and lower continental crust to the Earth's surface. During this process, high-grade metamorphic rocks (eclogite-, granulite- to amphibolite- facies) are exposed below low-angle detachment faults (and mylonitic shear zones) that show ductile deformation on the lower side (footwall) with amphibolite- to greenschist-facies syndeformational metamorphism, and ductile-brittle to brittle deformation on the upper-side (hanging-wall) with tilted geometries. Descriptions * stated that they: are characterized by a generally heterogeneous, older metamorphic-plutonic basement terrane overprinted by low-dipping lineated and foliated mylonitic and gneissic fabrics. An unmetamorphosed cover terrane is typically attenuated and sliced by numerous subhorizontal younger-on-older faults. Between the basem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detachment Fault
A detachment fault is a gently dipping normal fault associated with large-scale extensional tectonics. Detachment faults often have very large displacements (tens of km) and juxtapose unmetamorphosed hanging walls against medium to high-grade metamorphic footwalls that are called metamorphic core complexes. They are thought to have formed as either initially low-angle structures or by the rotation of initially high-angle normal faults modified also by the isostatic effects of tectonic denudation. They may also be called denudation faults. Examples of detachment faulting include: *The Snake Range detachment system of the Basin and Range Province of western North America which was active during the Miocene *The Nordfjord-Sogn detachment of western Norway active during the Devonian Period *The Whipple detachment in southeastern California Detachment faults have been found on the sea floor close to divergent plate boundaries characterised by a limited supply of upwelling magma, su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of The Grand Canyon Area
The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock (geology), rock on Earth. The nearly 40 major sedimentary rock layers exposed in the Grand Canyon and in the Grand Canyon National Park area range in age from about 200 million to nearly 2 billion years old. Most were deposited in warm, shallow seas and near ancient, long-gone sea shores in western North America. Both marine and terrestrial sediments are represented, including lithified sand dunes from an extinct desert. There are at least 14 known Unconformity, unconformities in the geologic record found in the Grand Canyon. Uplift of the region started about 75 million years ago during the Laramide orogeny; a mountain-building event that is largely responsible for creating the Rocky Mountains to the east. In total, the Colorado Plateau was uplifted an estimated . The adjacent Basin and Range Province to the west started to form about 18 million years ago as th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Craton
North is one of the four compass points or cardinal directions. It is the opposite of south and is perpendicular to east and west. ''North'' is a noun, adjective, or adverb indicating direction or geography. Etymology The word ''north'' is related to the Old High German ''nord'', both descending from the Proto-Indo-European unit *''ner-'', meaning "left; below" as north is to left when facing the rising sun. Similarly, the other cardinal directions are also related to the sun's position. The Latin word ''borealis'' comes from the Greek '' boreas'' "north wind, north", which, according to Ovid, was personified as the wind-god Boreas, the father of Calais and Zetes. ''Septentrionalis'' is from ''septentriones'', "the seven plow oxen", a name of ''Ursa Major''. The Greek ἀρκτικός (''arktikós'') is named for the same constellation, and is the source of the English word ''Arctic''. Other languages have other derivations. For example, in Lezgian, ''kefer'' can mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Farallon Plate
The Farallon Plate was an ancient oceanic plate. It formed one of the three main plates of Panthalassa, alongside the Phoenix Plate and Izanagi Plate, which were connected by a triple junction. The Farallon Plate began subducting under the west coast of the North American Plate—then located in modern Utah—as Pangaea broke apart and after the formation of the Pacific Plate at the centre of the triple junction during the Early Jurassic. It is named for the Farallon Islands, which are located just west of San Francisco, California. Over time, the central part of the Farallon Plate was completely subducted under the southwestern part of the North American Plate. The remains of the Farallon Plate are the Juan de Fuca, Explorer and Gorda Plates, subducting under the northern part of the North American Plate; the Cocos Plate subducting under Central America; and the Nazca Plate subducting under the South American Plate. The Farallon Plate is also responsible for transporting old i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North American Cordillera
The North American Cordillera, sometimes also called the Western Cordillera of North America, the Western Cordillera or the Pacific Cordillera, is the North American portion of the American Cordillera, the mountain chain system (cordillera) along the western coast (Pacific coast) of the Americas. The North American Cordillera covers an extensive area of mountain ranges, intermontane basins and plateaus in Western/ Northwestern Canada, Western United States and Mexico, including much of the territory west of the Great Plains. The precise boundaries of this cordillera and its subregions, as well as the names of its various features, may differ depending on the definitions in each country or jurisdiction, and also depending on the scientific field; this cordillera is a particularly prominent subject in the scientific field of physical geography.Melanie Ostopowich (2005) The Cordillera', Weigl Educational Publishers Limited, , pp. 6, 12, and 20: "The Cordillera is one of the seven g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colorado River Extensional Corridor
Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is the eighth most extensive and 21st most populous U.S. state. The 2020 United States census enumerated the population of Colorado at 5,773,714, an increase of 14.80% since the 2010 United States census. The region has been inhabited by Native Americans and their ancestors for at least 13,500 years and possibly much longer. The eastern edge of the Rocky Mountains was a major migration route for early peoples who spread throughout the Americas. "''Colorado''" is the Spanish adjective meaning "ruddy", the color of the Fountain Formation outcroppings found up and down the Front Range of the Rocky Mountains. The Territory of Colorado was organized on February 28, 1861, and on August 1, 1876, U.S. President Ulysses S. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of the entire Phanerozoic. The name is derived from the Latin ''creta'', "chalk", which is abundant in the latter half of the period. It is usually abbreviated K, for its German translation ''Kreide''. The Cretaceous was a period with a relatively warm climate, resulting in high eustatic sea levels that created numerous shallow inland seas. These oceans and seas were populated with now- extinct marine reptiles, ammonites, and rudists, while dinosaurs continued to dominate on land. The world was ice free, and forests extended to the poles. During this time, new groups of mammals and birds appeared. During the Early Cretaceous, flowering plants appeared and began to rapidly diversify, becoming the dominant group of plants across the Earth b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
