|
Muddy Creek Formation
The Muddy Creek Formation is a geologic formation in Arizona, California, Nevada, and Utah. It preserves fossils dating back to the Neogene period. Distribution and General Expression The following description is from USGS Bulletin 798 by C. R. Longwell in 1928: In all the large intermontane valleys adjacent to the Muddy Mountains and neighboring ranges there are thick clays or silts and associated deposits that have been relatively little disturbed by crustal deformation. As a rule they form belts from a fraction of a mile to several miles wide on each side of present stream valleys, above which the clay outcrops rise to a maximum height of approximately 600 feet. Adjacent to the high lands they feather out, lapping up on the older rocks. Between the Muddy and Virgin Mountains the area occupied by the clays is from 9 to 12 miles wide. South of St. Thomas this large area is divided into two nearly equal belts by Virgin River, and to the north the clays are cut by the convergin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of the Cenozoic and the eleventh period of the Phanerozoic. The Neogene is sub-divided into two epochs, the earlier Miocene and the later Pliocene. Some geologists assert that the Neogene cannot be clearly delineated from the modern geological period, the Quaternary. The term "Neogene" was coined in 1853 by the Austrian palaeontologist Moritz Hörnes (1815–1868). The earlier term Tertiary Period was used to define the span of time now covered by Paleogene and Neogene and, despite no longer being recognized as a formal stratigraphic term, "Tertiary" still sometimes remains in informal use. During this period, mammals and birds continued to evolve into modern forms, while other groups of life remained relatively unchanged. The first human ... [...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. kaolinite, ). 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. Clays develop plasticity (physics), plasticity when wet but can be hardened through Pottery#Firing, firing. Clay is the longest-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 radiocarbon dating, dated to around 14,000 BCE, and Clay tablet, clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtration, filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, often baked into brick, as an essenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology In Arizona
Paleontology in Arizona refers to paleontological research occurring within or conducted by people from the U.S. state of Arizona. The fossil record of Arizona dates to the Precambrian. During the Precambrian, Arizona was home to a shallow sea which was home to jellyfish and stromatolite-forming bacteria. This sea was still in place during the Cambrian period of the Paleozoic era and was home to brachiopods and trilobites, but it withdrew during the Ordovician and Silurian. The sea returned during the Devonian and was home to brachiopods, corals, and fishes. Sea levels began to rise and fall during the Carboniferous, leaving most of the state a richly vegetated coastal plain during the low spells. During the Permian, Arizona was richly vegetated but was submerged by seawater late in the period. During the Triassic, Arizona was home to a rich forest home to dinosaurs and early relatives of mammals. Jurassic Arizona had a drier climate and was covered by sand dunes where dinosaurs l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Fossiliferous Stratigraphic Units In Arizona
This article contains a list of fossil-bearing stratigraphic units in the state of Arizona, Arizona, U.S. Sites See also * Paleontology in Arizona References * {{DEFAULTSORT:Fossiliferous stratigraphic units in Arizona Fossiliferous stratigraphic units of the United States, Arizona Paleontology in Arizona, Stratigraphic units Stratigraphy of Arizona Arizona geography-related lists United States geology-related lists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconformity
An unconformity is a buried erosional or non-depositional surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger layer, but the term is used to describe any break in the sedimentary geologic record. The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at Siccar Point in Berwickshire in 1788, both in Scotland. The rocks above an unconformity are younger than the rocks beneath (unless the sequence has been overturned). An unconformity represents time during which no sediments were preserved in a region or were subsequently eroded before the next deposition. The local record for that time interval is missing and geologists must use other clues to discover that part of the geologic history of that area. The interval ... [...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 whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meadow Valley Wash
The Meadow Valley Wash is a southern List of Nevada rivers, Nevada stream draining the Meadow Watershed that is bordered on three sides by the Great Basin Divide. The wash's Lincoln County, Nevada, Lincoln County head point is in the Wilson Creek Range, and the wash includes two upper confluences (e.g., the Patterson Wash). Panaca, Nevada, Panaca is along the upper wash, and downstream of Caliente, Nevada, Caliente is the wash's confluence with its east fork. Just before the junction with the Muddy River (Nevada), Muddy River, the wash flows from Lincoln County into northeastern Clark County, Nevada, Clark County. It flows into the Muddy in the Moapa Valley just west of Glendale, Nevada, Glendale adjacent to Interstate 15 in Nevada, Interstate 15 approximately northeast of Las Vegas, Nevada, Las Vegas. In addition to the Wilson Creek Range, the watershed's drainage divide is in the Delamar Mountains (to the west) and the Meadow Valley Range (east). The northern tip of the wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mormon Mountains
The Mormon Mountains are located in Lincoln and Clark counties in Nevada, between 16 and northwest of Mesquite on I–15 in the Virgin Valley, east of the Meadow Valley Mountains and Meadow Valley and northeast of Moapa Valley.''Overton, Nevada–Arizona'', 30x60 Minute Topographic Quadrangle, USGS, 1987 The highest point in the range is Mormon Peak, at above sea level.''Moapa Peak NW, Nevada,'' 7.5 Minute Quadrangle, USGS, 1969 Another smaller mountain range lies to the east, called the East Mormon Mountains. The south fork of the Toquop Wash drains the east side of the range and continues on through the N–S linear ridge of the East Mormon Mountains. The mountains fall under the jurisdiction of the Bureau of Land Management (BLM) and cover approximately . The Mormon Mountains are home to several different species of lizards, and ground snakes, toads and bullfrogs can be found in the region. The lower elevations of the range are mostly shrublands, but at higher elevat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgin River
The Virgin River is a tributary of the Colorado River in the U.S. states of Utah, Nevada, and Arizona. The river is about long.Calculated with Google Maps and Google Earth It was designated Utah's first wild and scenic river in 2009, during the centennial celebration of Zion National Park. History The first known Euro-American party to encounter the Virgin was led by Jedediah Smith in 1826. Smith named it "Adams River", after then-president John Quincy Adams.Smith, Jedediah S., arrison G. Rogers and George R. Brooks (ed.). ''The Southwest Expedition of Jedediah S. Smith: His Personal Account of the Journey to California, 1826–1827'', p. 55. Lincoln and London, University of Nebraska Press, 9771989. Later explorer and mapmaker John C. Fremont reported that it was called "Rio Virgen" but did not state the origin of the name. Hiram Chittenden speculated that Smith had later renamed the river after Thomas Virgin, who was badly wounded in an 1827 attack by Mohave people durin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virgin Mountains
The Virgin Mountains are a mountain range of the northeastern Mojave Desert, located in Clark County, southeastern Nevada and Mohave County, northwestern Arizona. Geography Virgin Peak, at in elevation, is the highest point in the range. The range is northeast of Lake Mead, and around south of the Nevada town of Mesquite. Hydrologically, the range is located in the Lower Colorado—Lake Mead watershed. (USGS Huc 1501), 91.6% of the range is managed by the Bureau of Land Management, with a section of the Virgin Peak area designated within the BLM Virgin Mountain Natural Area. Natural history The range has many species of lizards, as well as the Panamint rattlesnake and glossy snake. Trees found in the range include Single-leaf pinyon pine (''Pinus monophylla''), Arizona cypress (''Cupressus arizonica''), White fir (''Abies concolor''), Douglas fir (''Pseudotsuga menziesii''), and Utah juniper (''Juniperus osteosperma''), and Rocky Mountain juniper (''Juniperus scopu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silt
Silt is granular material of a size between sand and clay and composed mostly of broken grains of quartz. Silt may occur as a soil (often mixed with sand or clay) or as sediment mixed in suspension (chemistry), suspension with water. Silt usually has a floury feel when dry, and lacks Plasticity (physics), plasticity when wet. Silt can also be felt by the tongue as granular when placed on the front teeth (even when mixed with clay particles). Silt is a common material, making up 45% of average modern mud. It is found in many river deltas and as wind-deposited accumulations, particularly in central Asia, north China, and North America. It is produced in both very hot climates (through such processes as collisions of quartz grains in dust storms) and very cold climates (through such processes as glacial grinding of quartz grains.) Loess is soil rich in silt which makes up some of the most fertile agricultural land on Earth. However, silt is very vulnerable to erosion, and it has poo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muddy Mountains
The Muddy Mountains are a large mountain range in Clark County, Nevada. The Muddy Mountains surround a north section of Bitter Spring Valley, which also lies at the northwest perimeter of the Black Mountains, lying on a north shore of an east-west section of Lake Mead. File:Cross bedding in Aztec Sandstone.jpg, Cross bedding in Aztec Sandstone, Muddy Mountains Wilderness Area File:Muddy Mountains, Nevada.jpg, Muddy Mountains seen from the Valley of Fire State Park, Nevada The Muddy Mountains Wilderness consists of 48,154 acres and was established by the U.S. Congress in 2002. The wilderness area is managed by the U.S. Bureau of Land Management and the National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government, within the US Department of the Interior. The service manages all List .... Elevations in the area range from 1,700 feet (518 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
