Basin and Range Province
The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins; the physiography of the province is the result of tectonic extension that began around 17 million years ago in the early Miocene epoch. The numerous ranges within the province in the United States are collectively referred to as the "Great Basin Ranges", although many are not in the Great Basin. Major ranges include the Snake Range, the Panamint Range, the White Mountains, the Sandia Mountains, the Tetons; the highest point within the province is White Mountain Peak in California, while the lowest point is the Badwater Basin in Death Valley at −282 feet. The province's climate is arid, with numerous ecoregions. Most North American deserts are located within it. Clarence Dutton famously compared the many narrow parallel mountain ranges that distinguish the unique topography of the Basin and Range to an "army of caterpillars marching toward Mexico."
The Basin and Range Province should not be confused with The Great Basin, a sub-section of the greater Basin and Range physiographic region defined by its unique hydrological characteristics. The Basin and Range Province includes much of western North America. In the United States, it is bordered on the west by the eastern fault scarp of the Sierra Nevada and spans over 500 miles to its eastern border marked by the Wasatch Fault, the Colorado Plateau and the Rio Grande Rift; the province extends north to the Columbia Plateau and south as far as the Trans-Mexican Volcanic Belt in Mexico, though the southern boundaries of the Basin and Range are debated. In Mexico, the Basin and Range Province is dominated by and synonymous with the Mexican Plateau. Evidence suggests that the less-recognized southern portion of the province is bounded on the east by the Laramide Thrust Front of the Sierra Madre Oriental and on the west by the Gulf of California and Baja Peninsula with notably less faulting apparent in the Sierra Madre Occidental in the center of the southernmost Basin and Range Province.
Common geographic features include numerous endorheic basins, ephemeral lakes and valleys alternating with mountains. The area is arid and sparsely populated, although there are several major metropolitan areas, such as Las Vegas and Tucson, it is accepted that basin and range topography is the result of extension and thinning of the lithosphere, composed of crust and upper mantle. Extensional environments like the Basin and Range are characterized by listric normal faulting, or faults that level out with depth. Opposing normal faults link at depth producing a horst and graben geometry, where horst refers to the upthrown fault block and graben to the down dropped fault block; the average crustal thickness of the Basin and Range Province is 30 – 35 km and is comparable to extended continental crust around the world. The crust in conjunction with the upper mantle comprises the lithosphere; the base of the lithosphere beneath the Basin and Range is estimated to be about 60 – 70 km. Opinions vary regarding the total extension of the region.
Total lateral displacement in the Basin and Range varies from 60 – 300 km since the onset of extension in the Early Miocene with the southern portion of the province representing a greater degree of displacement than the north. Evidence exists to suggest that extension began in the southern Basin and Range and propagated north over time; the tectonic mechanisms responsible for lithospheric extension in the Basin and Range province are controversial, several competing hypotheses attempt to explain it. Key events preceding Basin and Range extension in the western United States include a long period of compression due to the subduction of the Farallon Plate under the west coast of the North American continental plate which stimulated the thickening of the crust. Most of the pertinent tectonic plate movement associated with the province occurred in Neogene time and continues to the present. By Early Miocene time, much of the Farallon Plate had been consumed, the seafloor spreading ridge that separated the Farallon Plate from the Pacific Plate approached North America.
In the Middle Miocene, the East Pacific Rise was subducted beneath North America ending subduction along this part of the Pacific margin. The movement at this boundary divided the East Pacific Rise and spawned the San Andreas transform fault, generating an oblique strike-slip component. Today, the Pacific Plate moves north-westward relative to North America, a configuration which has given rise to increased shearing along the continental margin; the tectonic activity responsible for the extension in the Basin and Range is a complex and controversial issue among the geoscience community. The most accepted hypothesis suggests that crustal shearing associated with the San Andreas Fault caused spontaneous extensional faulting similar to that seen in the Great Basin. However, plate movement alone does not account for the high elevation of the Range region; the western United States is a region of high heat flow which lowers the density of the lithosphere and stimulates isostatic uplift as a consequence.
Lithospheric regions characterized by elevated heat flow are weak and extensional deformation can occur over a broad region. Basin and Range extension is therefore thought to be unrelated to the kind of extension produced by mantle upw
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, the natural hazards that threaten it; the organization has four major science disciplines, concerning biology, geography and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility; the USGS is a bureau of the United States Department of the Interior. The USGS employs 8,670 people and is headquartered in Reston, Virginia; the USGS has major offices near Lakewood, Colorado, at the Denver Federal Center, Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world." The agency's previous slogan, adopted on the occasion of its hundredth anniversary, was "Earth Science in the Public Service." Since 2012, the USGS science focus is directed at six topical "Mission Areas", namely Climate and Land Use Change, Core Science Systems, Ecosystems and Minerals and Environmental Health, Natural Hazards, Water.
In December 2012, the USGS split the Energy and Minerals and Environmental Health Mission Area resulting in seven topical Mission Areas, with the two new areas being: Energy and Minerals and Environmental Health. Administratively, it is divided into six Regional Units. Other specific programs include: Earthquake Hazards Program monitors earthquake activity worldwide; the National Earthquake Information Center in Golden, Colorado on the campus of the Colorado School of Mines detects the location and magnitude of global earthquakes. The USGS runs or supports several regional monitoring networks in the United States under the umbrella of the Advanced National Seismic System; the USGS informs authorities, emergency responders, the media, the public, both domestic and worldwide, about significant earthquakes. It maintains long-term archives of earthquake data for scientific and engineering research, it conducts and supports research on long-term seismic hazards. USGS has released the UCERF California earthquake forecast.
As of 2005, the agency is working to create a National Volcano Early Warning System by improving the instrumentation monitoring the 169 volcanoes in U. S. territory and by establishing methods for measuring the relative threats posed at each site. The USGS National Geomagnetism Program monitors the magnetic field at magnetic observatories and distributes magnetometer data in real time; the USGS collaborates with Canadian and Mexican government scientists, along with the Commission for Environmental Cooperation, to produce the North American Environmental Atlas, used to depict and track environmental issues for a continental perspective. The USGS operates the streamgaging network for the United States, with over 7400 streamgages. Real-time streamflow data are available online. National Climate Change and Wildlife Science Center implements partner-driven science to improve understanding of past and present land use change, develops relevant climate and land use forecasts, identifies lands and communities that are most vulnerable to adverse impacts of change from the local to global scale.
Since 1962, the Astrogeology Research Program has been involved in global and planetary exploration and mapping. In collaboration with Stanford University, the USGS operates the USGS-Stanford Ion Microprobe Laboratory, a world-class analytical facility for U--Pb geochronology and trace element analyses of minerals and other earth materials. USGS operates a number of water related programs, notably the National Streamflow Information Program and National Water-Quality Assessment Program. USGS Water data is publicly available from their National Water Information System database; the USGS operates the National Wildlife Health Center, whose mission is "to serve the nation and its natural resources by providing sound science and technical support, to disseminate information to promote science-based decisions affecting wildlife and ecosystem health. The NWHC provides information, technical assistance, research and leadership on national and international wildlife health issues." It is the agency responsible for surveillance of H5N1 avian influenza outbreaks in the United States.
The USGS runs 17 biological research centers in the United States, including the Patuxent Wildlife Research Center. The USGS is investigating collaboration with the social networking site Twitter to allow for more rapid construction of ShakeMaps; the USGS produces several national series of topographic maps which vary in scale and extent, with some wide gaps in coverage, notably the complete absence of 1:50,000 scale topographic maps or their equivalent. The largest and best-known topographic series is the 7.5-minute, 1:24,000 scale, quadrangle, a non-metric scale unique to the United States. Each of these maps covers an area bounded by two lines of latitude and two lines of longitude spaced 7.5 minutes apart. Nearly 57,000 individual maps in this series cover the 48 contiguous states, Hawaii, U. S. territories, areas of Alaska near Anchorage and Prudhoe Bay. The area covered by each map varies with the latitude of its represented location due to convergence of the meridians. At lower latitudes, near 30° north, a 7.5-minute quadrangle contains an area of about 64 square miles.
At 49° north latitude, 49 square miles are contained within a quadrangle of that size. As a unique non-metric map scale, the 1:24,000 scale requires a separate and specialized romer scale for pl
Trimble Inc. is a Sunnyvale, California-based developer of Global Navigation Satellite System receivers, laser rangefinders, unmanned aerial vehicles, inertial navigation systems and software processing tools. The company was founded in November 1978. Trimble Navigation was founded in November 1978 by Charles Trimble and two partners from Hewlett Packard operating from Los Altos, California. By the end of 2016, the company had 8,388 employees, with more than half of employees in locations outside the United States; the company's acquisitions include Pocket Mobile AB, @Road, Cengea Solutions Inc. Datacom Software Research, Spectra Precision Group, Tripod Data Systems, Advanced Public Safety, Inc. ALK Technologies, Apache Technologies, Acutest Engineering Solutions Ltd, Applanix, Géo-3D, INPHO, Gehry Technologies, Meridian Systems, NTech Industries, Pacific Crest, Accubid Systems, SketchUp, QuickPen International, SECO Mfg. Co. Inc. Visual Statement, Stabiplan, XYZ Solutions, Tekla, ThingMagic, Spime Inc.
Punch Telematix NV, TMW Systems and TopoSys Gmbh. Their role in building information modeling and construction has been growing. Most publicised was their 2012 acquisition of the 3D modeling software package SketchUp from Google; as of 2014 they own Tekla, Vico Office and Gehry Technologies' GTeam. In 2016, Trimble acquired Sefaira. On April 23, 2018, Trimble entered into an agreement to acquire held Viewpoint from investment firm Bain Capital in an all-cash transaction of US$1.2bn, with an expected completion in Q3 of 2018. On February 12, 2019, a new division called Trimble MAPS was launched, bringing together Trimble’s former ALK Technologies and TMW Appian Final Mile businesses; the company changed its name from Trimble Navigation Limited to Trimble Inc.. Trimble Inc. continued to operate without material impacts to stakeholders. The corporate headquarters remained in California. Trimble sells products and services into the following industries: land survey, agriculture, telecommunications, asset tracking, utilities, mobile resource management, government.
Utah State Route 21
State Route 21 is a state highway in western Utah, running for 107.575 miles in Millard and Beaver Counties from the Nevada state line near Garrison to Beaver. SR-21 begins at the Nevada state line as a continuation of Nevada State Route 487 and heads southeast through Garrison, it continues through Mormon Gap and Halfway Summit. It turns east around Lime Point over Wah Wah Summit, it heads southeast between Grampian Hill and Squaw Peak into Squaw Gulch, where it turns northeast over Frisco Summit and east through the ghost town of Frisco. It turns southeast and continues to Milford. SR-21 leaves Milford heading southeast across an agricultural area to Minersville. In Minersville, it turns east past Yellow Mountain turns northeast past Minersville Lake State Park, it continues through Adamsville turns east around Little Bald Hill through Greenville into Beaver. In Beaver, it crosses I-15 without an interchange, the continues to end at an intersection with Business Loop I-15; the road from SR-1 in Beaver west to Milford was added to the state highway system in 1910, it was extended west to Newhouse in 1916.
The state legislature assigned the SR-21 designation to the route in 1927, continued it northwest from Newhouse to the Nevada state line, where it became SR 73 towards Ely. In 1941, SR-21 was extended east from Beaver to US-89 at Junction, but this became SR-153 in 1945. Media related to Utah State Route 21 at Wikimedia Commons
The Sevier Desert is a large arid section of central-west Utah, United States, is located in the southeast of the Great Basin. It is bordered by deserts north and south, its eastern border is the East Tintic and Canyon Mountains. The Sevier Desert contains the course of the Sevier River in a circuitous manner, it flows to Sevier Lake in the extreme southwest Sevier Desert. The Sevier River enters the east desert flowing west turning southwest west, to enter the north of Sevier Lake, south-southwest trending; the southeast section of the desert contains the Black Rock Desert volcanic field, with the notable Pavant Butte, a formation from the time of Lake Bonneville. The volcanic field region is west of an agricultural four-city region from McCornick to Fillmore; the Little Sahara National Recreation Area is located in the northeast of the desert. The desert is about 105-mi long north-south, about 60-mi wide; the desert covers a large section of the central-north Sevier River drainage, much of the east half of Millard County.
The Sevier Desert is named for the river, derived from "Rio Severo", a local name given by early Spanish explorers. In the north and northwest, the desert is composed of small mountain ranges, a few valleys and borders the south-southeast of the Great Salt Lake Desert; the Dugway Range and Dugway Valley on the Great Salt Lake Desert's perimeter, borders the Thomas Range, southeast. The Thomas Range and Drum Mountains lie due west of the Little Sahara Recreation Site. A large dissected flatland lies between drained southwesterly by Cherry Creek Wash; the region contains intermittent reservoirs, Crater Bench, Desert Mountain Reservoir. Various springs, or wells, it is the site of Fumarole Butte, 5,278 feet, about 10 miles east of the Drum Mountains. The west perimeter of the Sevier Desert has a north-south border because of the House Range; the south desert perimeter is east-west because the mountains on the south separate the Sevier from the Escalante Desert, an approximate triangle-shaped desert enclosed amongst mountain ranges, the Escalante and Cedar Valleys.
The east of the Sevier Desert contains the communities lying at the foothills of the mountain ranges. The Black Rock Desert volcanic field is located west of the cities. Pavant Valley lies at the west of the Pavant Range, west of the Canyon Mountains lies the Oak Creek Sinks adjacent east of the Sevier River, west of Oak City; the northeast perimeter of the desert lies at the southwest foothills of the East Tintic Mountains, noted for its mining. Tintic Valley, a small valley between the West Tintic Mountains feeds southwesterly into the Sevier Desert. Adjacent west of the West Tintics, lie two additional bordering mountain ranges, the southwest flank of the Sheeprock Mountains and the small, circular Simpson Mountains west. In the west and southwest, west of the House Range, is the Ferguson Desert; the following is a list of communities or landforms associated with the north, south and west desert perimeters. Interstate 15 transits the southeast perimeter of the desert along mountain foothills.
Utah State Route 257 transits north northeast through the center-east desert, from Black Rock, Utah to Oasis. U. S. 6 continues northeast from Oasis to Jericho and McIntyre, at the northeast perimeter of the desert. U. S. 6 is the access route to the Little Sahara Recreation Area in the northeast. Utah Atlas & Gazetteer, DeLorme, 7th Ed, c. 2010, 64 pages
Sevier Lake is an intermittent and endorheic lake which lies in the lowest part of the Sevier Desert, Millard County, Utah. Like Great Salt Lake and Utah Lake, it is a remnant of Pleistocene Lake Bonneville. Sevier Lake is fed by the Beaver and Sevier rivers, the additional inflow is from the lake's watershed, part of the Escalante–Sevier hydrologic subregion; the lake has been dry throughout recorded history and is a source of wind-blown dust. The first recorded observation was in 1872, which stated that the lake's surface area was 188 square miles, salinity was measured at 86 parts per thousand, two and a half times that of the ocean, maximum depth was 15 feet. In January 1880 the lake was nearly dry, had been so for the past one or two years; the Sevier River which once flowed to the lake is now diverted for irrigation. In 1987 however, the lake was again similar to the recorded description of 1872; the Dominguez–Escalante Expedition named it "Laguna de Miera" after Bernardo de Miera y Pacheco, a cartographer on their 1776 expedition.
In 1825, trappers working for William Henry Ashley trapped the region, Jedediah Smith named it after him, the Ashley Lake. On some maps, it was named after Joseph Nicollet in the mid-19th century; the lake is named for the river, derived from "Rio Severo", a local name given by early Spanish explorers. During late 2011, due to an unusually wet year, many man-made reservoirs in Millard County began dumping excess water through the Sevier River onto the Sevier Lake bed. Standing water existed on the playa for the first time since 1984 and extended down past Needle Point, the feature seen on the west edge of the lake. In the deepest points water levels were over three feet deep. Due to high salinity content, of over 20% TDS, the water never froze from the winter temperatures, which were well below 32 °F, except near the inlet of the Sevier River. A development-stage potassium sulfate project is being developed on Sevier Dry Lake headed up by Crystal Peak Minerals. Extensive exploration drilling and other test work has been completed over the entire playa.
In 2018, CPM published an NI 43-101 feasibility study for the production of potassium sulfate. The FS forecasts average annual SOP production over the 30-year life of the Project of 298,000 metric tonnes of potassium sulfate. Terminal Lake Systems - Sevier Lake. Utah Water Research Laboratory, Utah State University Utah History Encyclopedia. Sevier River Flooding 1983-1984. WaterHistory.org
A dry lake is either a basin or depression that contained a standing surface water body, which disappeared when evaporation processes exceeded recharge. If the floor of a dry lake is covered by deposits of alkaline compounds, it is known as an alkali flat. If covered with salt, it is known as a salt flat. If its basin is salt a dry lake is called a salt pan, pan, or salt flat. Hardpan is the dry terminus of an internally drained basin in a dry climate, a designation used in the Great Basin of the western United States. Another term for dry lake is playa; the Spanish word playa means "beach". Dry lakes are known by this name in some parts of the western United States; this term is used on the Llano Estacado and other parts of the Southern High Plains. In South America, the usual term for a dry lake is Spanish for salt pan. Pan is the term used in most of South Africa; these may include the small round highveld pans, typical of the Chrissiesmeer area, to the extensive pans of the Northern Cape province.
Terms used in Australia include salt pans and clay pans. In Arabic, an alkali flat is called a shott. In Central Asia, a similar "cracked mud" salt flat is known as a takyr. In Iran salt flats are called kavir. A dry lake is formed when water from rain or other sources, like intersection with a water table, flows into a dry depression in the landscape, creating a pond or lake. If the total annual evaporation rate exceeds the total annual inflow, the depression will become dry again, forming a dry lake. Salts dissolved in the water precipitate out and are left behind building up over time. A dry lake appears as a flat bed of clay encrusted with precipitated salts; these evaporite minerals are a concentration of weathering products such as sodium carbonate and other salts. In deserts, a dry lake may be found in an area ringed by bajadas. Dry lakes are formed in semi-arid to arid regions of the world; the largest concentration of dry lakes is in the southern High Plains of Texas and eastern New Mexico.
Most dry lakes are small. However, Salar de Uyuni in Bolivia, near Potosí, the largest salt flat in the world, comprises 4,085 square miles. Many dry lakes contain shallow water during the rainy season during wet years. If the layer of water is thin and is moved around the dry lake by wind, an exceedingly hard and smooth surface may develop. Thicker layers of water may result in a "cracked-mud" surface and "teepee" structure desiccation features. If there is little water, dunes can form; the Racetrack Playa, located in Death Valley, features a geological phenomenon known as "sailing stones" that leave linear "racetrack" imprints as they move across the surface without human or animal intervention. These rocks have been filmed in motion by the Scripps Institution of Oceanography at UC San Diego and are due to a perfect coincidence of events. First, the playa has to fill with water, which must be deep enough to form floating ice during winter, but still shallow enough that the rocks are exposed.
When the temperature drops at night, this pond freezes into thin sheets of "windowpane" ice, which must be thick enough to maintain strength, but thin enough to move freely. When the sun comes out, the ice melts and cracks into floating panels; the stones only move once most tracks last for three or four years. While a dry lake is itself devoid of vegetation, they are ringed by shadscale and other salt-tolerant plants that provide critical winter fodder for livestock and other herbivores. In southwest Idaho and parts of Nevada and Utah there are a number of rare species that occur nowhere else but in the inhospitable environment of seasonally flooded playas. A new species of giant fairy shrimp was found in 2006. Although a large predatory species, it evaded detection because of the murkiness of the playa's water caused by winds and a fine clay load; this shrimp species is able to regenerate using tiny undetectable cysts that can remain in a dry lake bed for years until conditions are optimum for hatching.
Lepidium davisii is another rare species, a perennial plant whose habitat is restricted to playas in southern Idaho and northern Nevada. Far from major rivers or lakes, playas are the only water available to wildlife in the desert. Antelope and other wildlife gather there. Threats to dry lakes include pollution from concentrated animal feeding operations such as cattle feedlots and dairies. Results are erosion. A non-native shrub, used for rangeland restoration in the west, Kochia prostrata poses a significant threat to playas and their associated rare species, as it capable of crowding out native vegetation and draining a playa's standing water because of its root growth; the flat and hard surfaces of dry lakes make them ideal for motor vehicles and bicycles. Furthermore, large-sized dry lakes are excellent spots for pursuing land speed records, as the smoothness of the surface allows low-clearance vehicles to travel fast without any risk of disruption by surface irregularities, the path traveled has no obstacles to avoid.
The dry lakes at Bonneville Salt Flats in Utah and Black Rock Desert in Nevada have both been used for setting land speed records. Lake Eyre and Lake Gairdner in South Australia have been used for variou