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81-503: Nomenclature for this peak and its range varies. The highest peak is sometimes known as Sleeping Ute Mountain; the entire range is also identified as one large mountain, called Sleeping Ute Mountain, on some maps; and the range is sometimes called the Sleeping Ute Mountains. All of these forms of the mountain's name and of the range's name can be found on various USGS maps, databases and reports. The Ute Mountains, with

162-438: A central volcano or intrusion. Though they appear to originate in the central intrusion, the dikes often have a different age and composition from the intrusion. These radial swarms may have formed over the intrusion and were later cut by the rising body of magma, or the crust was already experiencing regional tension and the intrusion triggered formation of the fissures. In rock of the oceanic crust, pillow lava erupted onto

243-460: A curtain of fire where lava erupts along the entire length of a fissure several kilometers long. However, the length of erupting fissure diminishes over time, becoming focused on a short segment of less than half a kilometer. The minimum possible width of a dike is determined by the balance between magma movement and cooling. There may be more than one injection of magma along a given fissure. When multiple injections are all of similar composition,

324-497: A sill is a sheet intrusion that forms within and parallel to the bedding. Mafic magma (fluid magma low in silica) usually reaches the surface through fissures, forming dikes. At the shallowest depths, dikes form when magma rises into an existing fissure. In the young, shallow dikes of the Hawaiian Islands, there is no indication of forceful intrusion of magma. For example, there is little penetration of magma into

405-473: A collective profile commonly known as "The Sleeping Ute", are a dense cluster of peaks approximately 5 by 12 miles (8 by 19 km) in extent and stand in isolation from other mountains. Despite being much lower than Colorado's highest peaks , Ute Mountain is the eighth most topographically prominent peak in the state, due to this isolation. It is also notable for its large local relief in all directions, especially its rise of roughly 4,250 ft (1,295 m) over

486-425: A consequence of the direction of minimum principal stress changing as the magma ascends from deep to shallow levels in the crust. An en echelon dike set may evolve into single dike with bridges connecting the formerly separate segments and horns showing former segment overlaps. In ancient dikes in deformed rock, the bridges and horns are used by geologists to determine the direction of magma flow. Where there

567-581: A dike is much smaller than its other two dimensions, and the opposite walls are roughly parallel, so that a dike is more or less constant in thickness. The thickness of different dikes can range from a few millimeters to hundreds of meters, but is most typically from about a meter to a few tens of meters. The lateral extent can be tens of kilometers, and dikes with a thickness of a few tens of meters or more commonly extend for over 100 km. Most dikes are steeply dipping; in other words, they are oriented nearly vertically. Subsequent tectonic deformation may rotate

648-593: A federal survey agency, in part to inventory the vast lands added to the United States by the Louisiana Purchase in 1803 and the Mexican–American War in 1848. The USGS was authorized on March 3 in a last-minute amendment to an unrelated bill that charged the new agency with the "classification of the public lands, and examination of the geological structure, mineral resources, and products of

729-538: A great battle with "the Evil Ones". Various other forms of the legend can be found. Readily recognized from many spots up to 50 miles (80 km) east or west (e.g. the Four Corners Monument and parts of Mesa Verde National Park ), the profile is best seen from 15 to 25 miles (24 to 40 km) somewhat north of east of the mountains as in the accompanying photograph. Easily identified features of

810-449: A lack of accuracy and detail in comparison to older generation maps based on aerial photo surveys and field checks. As the digital databases were not designed for producing general-purpose maps, data integration can be a problem when retrieved from sources with different resolutions and collection dates. Human-made features once recorded by direct field observation are not in any public domain national database and are frequently omitted from

891-608: A line extending for 250 km. Individual segments overlap, with the overlapping portions thinner, so that the combined thickness of the two overlapped portions is about the same as the thickness of a single segment. Other examples of en echelon dikes are the Inyo dike of Long Valley, California , US; the Jagged Rocks complex, Arizona , US; and the dikes of oceanic spreading centers . Dikes range in composition from basaltic to rhyolitic , but most are basaltic. The texture

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972-677: A new way to view their entire digitized collection of over 178,000 maps from 1884 to 2006. The site is an interactive map of the United States that allows users to search or move around the map to find the USGS collection of maps for a specific area. Users may then view the maps in great detail and download them if desired. In 2008 the USGS abandoned traditional methods of surveying, revising, and updating topographic maps based on aerial photography and field checks. Today's U.S. Topo quadrangle (1:24,000) maps are mass-produced, using automated and semiautomated processes, with cartographic content supplied from

1053-410: A non-metric scale virtually 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 , and areas of Alaska near Anchorage , Fairbanks , and Prudhoe Bay . The area covered by each map varies with

1134-528: A number of specific science programs, facilities, and other organizational units: The Earthquake Hazards Program monitors earthquake activity worldwide. The National Earthquake Information Center (NEIC) in Golden, Colorado , on the campus of the Colorado School of Mines detects the location and magnitude of global earthquakes. The USGS also runs or supports several regional monitoring networks in

1215-846: 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 also operates the National Wildlife Health Center , whose mission is "to serve the nation and its natural resources by providing sound science and technical support, and to disseminate information to promote science-based decisions affecting wildlife and ecosystem health. The NWHC provides information, technical assistance, research, education, and leadership on national and international wildlife health issues." It

1296-684: A result, some have noted that the U.S. Topo maps currently fall short of traditional topographic map presentation standards achieved in maps drawn from 1945 to 1992. The Hydrologic Instrumentation Facility (HIF) has four sections within its organizational structure; the Field Services Section which includes the warehouse, repair shop, and Engineering Unit; the Testing Section which includes the Hydraulic Laboratory, testing chambers, and Water Quality Laboratory;

1377-543: A ring fracture. Magma rising into the ring fracture produces a ring dike. Good examples of ring dikes and cone sheets are found in the Ardnamurchan peninsula of Scotland. A feeder dike is a dike that acted as a conduit for magma moving from a magma chamber to a localized intrusion . For example, the Muskox intrusion in arctic Canada was fed by a large dike, with a thickness of 150 meters. A sole injection

1458-663: A roadside there. The igneous rocks intrude a sedimentary section of Jurassic and Cretaceous rocks and the youngest rocks intruded are in the Point Lookout Sandstone. The intrusions are similar in form and rock type to those in other Colorado Plateau mountain ranges, such as the La Plata Mountains to the northeast of here, and the Rico Mountains north of Dolores, Colorado in Colorado, and

1539-411: A shallow magma chamber. Cone sheets form when magma is injected into a shallow magma chamber, which lifts and fractures the rock beds above it. The fractures take the form of a set of concentric cones dipping at a relatively shallow angle into the magma chamber. When the caldera is subsequently emptied by explosive volcanic activity, the roof of the magma chamber collapses as a plug of rock surrounded by

1620-478: A towing tank, jet tank, pipe flow facility, and tilting flume. In addition, the HIF provides training and technical support for the equipment it stocks. The Engineering Group seeks out new technology and designs for instrumentation that can work more efficiently, be more accurate, and or be produced at a lower cost than existing instrumentation. HIF works directly with vendors to help them produce products that will meet

1701-644: A variety of USGS Report Series that include preliminary results, maps, data, and final results. A complete catalog of all USGS publications is available from the USGS Publications Warehouse. In the mid-1800s, various states set up geological survey institutions; e.g., the Kentucky Geological Survey , established in 1854. In 1879, a report from the National Academy of Sciences prompted Congress to set up

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1782-709: Is a fact-finding research organization with no regulatory responsibility. It is headquartered in Reston, Virginia , with major offices near Lakewood, Colorado ; at the Denver Federal Center ; and in NASA Ames Research Park in California. In 2009, it employed about 8,670 people. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on its hundredth anniversary,

1863-514: Is a partnership-driven program that teams scientific researchers with natural and cultural resource managers to help fish, wildlife, waters, and lands across the country adapt to climate change . The National CASC (NCASC), based at USGS headquarters in Reston, Virginia, serves as the national office for the CASC network, while eight regional CASCs made up of federal-university consortiums located across

1944-457: Is concentrated on the tip of the propagating fracture. In effect, the magma wedges apart the brittle rock in a process called hydraulic fracture . At greater depths, where the rock is hotter and less brittle, the magma forces the rock aside along brittle shear planes oriented 35 degrees to the sides of the dock. This bulldozer-like action produces a blunter dike tip. At the greatest depths, the shear planes become ductile faults, angled 45 degree from

2025-436: Is formed in a fracture of a pre-existing rock body. Dikes can be either magmatic or sedimentary in origin. Magmatic dikes form when magma flows into a crack then solidifies as a sheet intrusion , either cutting across layers of rock or through a contiguous mass of rock. Clastic dikes are formed when sediment fills a pre-existing crack. A magmatic dike is a sheet of igneous rock that cuts across older rock beds. It

2106-408: Is formed when magma fills a fracture in the older beds and then cools and solidifies. The dike rock is usually more resistant to weathering than the surrounding rock, so that erosion exposes the dike as a natural wall or ridge. It is from these natural walls that dikes get their name. Dikes preserve a record of the fissures through which most mafic magma (fluid magma low in silica) reaches

2187-483: Is mapped at this scale in quadrangles measuring 1° by 1°. USGS topographic quadrangle maps are marked with grid lines and tics around the map collar which make it possible to identify locations on the map by several methods, including the graticule measurements of longitude and latitude, the township and section method within the Public Land Survey System , and cartesian coordinates in both

2268-408: Is rapid flow of molten magma through a fissure, the magma tends to erode the walls, either by melting the wall rock or by tearing off fragments of wall rock. This widens the fissure and increases flow. Where flow is less rapid, the magma may solidify next to the wall, narrowing the fissure and decreasing flow. This causes flow to become concentrated at a few points. At Hawaii, eruptions often begin with

2349-569: Is the Mackenzie dike swarm in the Northwest Territories , Canada. Dike swarms (also called dike complexes ) are exposed in the eroded rift zones of Hawaiian volcanoes. As with most other magmatic dikes, these were fissures through which lava reached the surface. The swarms are typically 2.5 to 5 km in width, with individual dikes about a meter in width. The dike swarms extend radially out from volcano summits and parallel to

2430-695: Is the P-wave velocity of the host rock (essentially, the speed of sound in the rock). This formula predicts that dikes will be longer and narrower at greater depths below the surface. The ratio of thickness to length is around 0.01 to 0.001 near the surface, but at depth it ranges from 0.001 to 0.0001. A surface dike 10 meters in thickness will extend about 3 km, while a dike of similar thickness at depth will extend about 30 km. This tendency of intruding magma to form shorter fissures at shallower depths has been put forward as an explanation of en echelon dikes. However, en echelon dikes have also been explained as

2511-529: Is the agency primarily responsible for surveillance of H5N1 avian influenza outbreaks in the United States. The USGS also 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. ShakeMaps are an interactive tool allowing users to visually observe

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2592-415: Is the thickness of the dike; b {\displaystyle b} is its lateral extent; P e x {\displaystyle P_{ex}} is the excess pressure in the magma relative to the host rock; ρ h o s t {\displaystyle \rho _{host}} is the density of the host rock; and V P {\displaystyle V_{P}}

2673-483: Is typically slightly coarser than basalt erupted at the surface, forming a rock type called diabase . The grain size varies systematically across the dike, with the coarsest grains normally at the center of the dike. Dikes formed at shallow depth commonly have a glassy or fine-grained chilled margin 1 to 5 cm thick, formed where the magma was rapidly cooled by contact with the cold surrounding rock. Shallow dikes also typically show columnar jointing perpendicular to

2754-416: Is usually dense, with almost no vesicles (frozen bubbles), but vesicles may be seen in the shallowest part of a dike. When vesicles are present, they tend to form bands parallel to walls and are elongated in direction of flow. Likewise, phenocrysts (larger crystals) on the margins of the dike show an alignment in the direction of flow. In contrast to dikes, which cut across the bedding of layered rock,

2835-860: The Henry Mountains , the La Sal Mountains and the Abajo Mountains , all to the west in Utah. The intrusions at these three Utah occurrences are younger at about 20 to 30 million years in age. The Ute Mountains and the similar Carrizo Mountains , nearby in Arizona, lie within a southwest extension of the Colorado Mineral Belt , but no ore deposits are known to be associated with these igneous rocks. Sedimentary units are listed below, from youngest to oldest: In some areas

2916-673: The Montezuma Valley to the southeast. The Sleeping Ute is said to resemble a Ute chief lying on his back with arms folded across his chest. The mountains were valued as a sacred place by the Weeminuche Ute band. It is still a sacred place to their descendants, the Ute Mountain Ute Tribe , and still plays a role in their ceremonies as indicated by the "Sundance Ground" on some topographical maps nestled between The Knees and Horse Peak (ribcage). Originally,

2997-599: The State Plane Coordinate System and the Universal Transverse Mercator coordinate system . Other specialty maps have been produced by the USGS at a variety of scales. These include county maps, maps of special interest areas, such as the national parks , and areas of scientific interest. A number of Internet sites have made these maps available on the web for affordable commercial and professional use. Because works of

3078-634: 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 also operates five volcano observatories throughout the nation: the Alaska Volcano Observatory in Anchorage, Alaska (on

3159-570: 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 , which is used to depict and track environmental issues for a continental perspective. The USGS operates the streamgaging network for

3240-442: The 15-minute series, was once used to map the contiguous 48 states at a scale of 1:62,500 for maps covering the continental United States, but was discontinued during the last quarter of the twentieth century. Each map was bounded by two parallels and two meridians spaced 15 minutes apart—the same area covered by four maps in the 7.5-minute series. The 15-minute series, at a scale of 1:63,360 (one inch representing one mile), remains

3321-439: The 30 x 60-minute quadrangle series. Each of these quadrangles covers the area contained within 32 maps in the 7.5-minute series. The 1:100,000 scale series is unusual in that it primarily employs the metric system . One centimeter on the map represents one kilometer of distance on the ground. Contour intervals , spot elevations, and horizontal distances are also specified in meters. The final regular quadrangle series produced by

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3402-980: The Information Technology Section which includes computer support and the Drafting Unit; and the Administrative Section. The HIF was given national responsibility for the design, testing, evaluation, repair, calibration, warehousing, and distribution of hydrologic instrumentation. Distribution is accomplished by direct sales and through a rental program. The HIF supports data collection activities through centralized warehouse and laboratory facilities. The HIF warehouse provides hydrologic instruments, equipment, and supplies for USGS as well as Other Federal Agencies (OFA) and USGS Cooperators. The HIF also tests, evaluates, repairs, calibrates, and develops hydrologic equipment and instruments. The HIF Hydraulic Laboratory facilities include

3483-523: The National GIS Database. In the two years from June 2009 to May 2011, the USGS produced nearly 40,000 maps, more than 80 maps per work day. Only about two hours of interactive work are spent on each map, mostly on text placement and final inspection; there are essentially no field checks or field inspections to confirm map details. While much less expensive to compile and produce, the revised digital U.S. topo maps have been criticized for

3564-544: The Reservation, Towaoc, lies at the feet of the figure and is home to most of the Reservation's population. As the Reservation capital, Towaoc is the Ute Mountain Ute tribal headquarters. Cortez, the largest town in the area with a population of over 8000, lies outside the reservation 11.5 miles (18.5 km) east-northeast of Ute Peak. The elevation of Cortez is 6,200 feet (1,890 m) and can be considered

3645-439: The Reservation. The Ute Mountains were formed by intrusion of igneous rocks at about 72 million years (Late Cretaceous ), concurrent doming, and subsequent erosion. The most common type of igneous rock is porphyritic hornblende diorite , but rock types present range from gabbro to granite . Forms of intrusions include laccoliths , stocks, dikes , and sills . One dike extends north to McElmo Creek and can be examined at

3726-473: The U.S. government are in the public domain , it is also possible to find many of these maps for free at various locations on the Internet. Georeferenced map images are available from the USGS as digital raster graphics (DRGs) in addition to digital data sets based on USGS maps, notably digital line graphs (DLGs) and digital elevation models (DEMs). In 2015, the USGS unveiled the topoView website,

3807-726: The U.S., U.S. Pacific Islands, and U.S. Caribbean deliver science that addresses resource management priorities of the states within their footprints. Since 1962, the Astrogeology Research Program has been involved in global, lunar , and planetary exploration and mapping . In collaboration with Stanford University , the USGS also operates the USGS-Stanford Ion Microprobe Laboratory, a world-class analytical facility for U-(Th)-Pb geochronology and trace element analyses of minerals and other earth materials. USGS operates

3888-933: The USGS Center for Coastal Geology) has three sites, one for the Atlantic Ocean (located in Woods Hole, Massachusetts ), one for the Pacific Ocean (located in Santa Cruz, California ) and one for the Gulf of Mexico (located on the University of South Florida's St. Petersburg campus). The goal of this department is to conduct research in geology, mapping, hydrology, biology, and related sciences; evaluate hazards associated with floods, droughts, hurricanes, subsidence, human activity, and climate change; map

3969-474: The USGS is the 1:250,000 scale topographic series. Each of these quadrangles in the conterminous United States measures 1 degree of latitude by 2 degrees of longitude. This series was produced by the U.S.  Army Map Service in the 1950s, prior to the maps in the larger-scale series, and consists of 489 sheets, each covering an area ranging from 8,218 square miles (21,285 km ) at 30° north to 6,222 square miles (16,115 km ) at 49° north. Hawaii

4050-576: The USGS to rely on donations of time by civilian volunteers in an attempt to update its 7.5-minute topographic map series, and USGS stated outright in 2000 that the program was to be phased out in favor of The National Map (not to be confused with the National Atlas of the United States produced by the Department of the Interior , one of whose bureaus is USGS). An older series of maps,

4131-494: The United States under the umbrella of the Advanced National Seismic System (ANSS). The USGS informs authorities, emergency responders, the media, and the public, both domestic and worldwide, about significant earthquakes. It maintains long-term archives of earthquake data for scientific and engineering research. It also conducts and supports research on long-term seismic hazards . USGS has released

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4212-912: The United States, with over 7400 streamgages . Real-time streamflow data are available online. As part of the Water Resources Research Act of 1984, the State Water Resources Research Act Program created a Water Resources Research Institute (WRRI) in each state, along with Washington DC, Puerto Rico, the US Virgin Islands, and Guam. Together, these institutes make up the National Institutes for Water Resources (NIWR). The institutes focus on water-related issues through research, training and collaboration. The National and regional Climate Adaptation Science Centers (CASCs)

4293-609: The base elevation of the Ute Mountains. The Ute Mountain Ute Tribal Park adjoins Mesa Verde National Park to the east of the mountains. The western boundary of Mesa Verde National Park is 12 miles (19 km) east of Ute Peak. The Mesa and the Sleeping Ute share equal prominence as regional landmarks. McElmo Creek and Canyon Of The Ancients National Monument form the northern terminus of the Ute Mountains and

4374-1200: The campus of Alaska Pacific University ), the California Volcano Observatory in Menlo Park, California , the Cascades Volcano Observatory (covering volcanoes in Idaho , Oregon , and Washington ) in Vancouver, Washington , the Hawaiian Volcano Observatory in Hilo, Hawaii , and the Yellowstone Volcano Observatory (covering volcanoes in Arizona , Colorado , Montana , New Mexico , Utah , and Wyoming ) in Yellowstone National Park , Wyoming. The USGS Coastal and Marine Science Center (formerly

4455-691: The center of the dike. If the previous dike rock has cooled significantly, the subsequent injection can be characterized by fracturing of the old dike rock and the formation of chilled margins on the new injection. Sometimes dikes appear in swarms, consisting of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event. Dike swarms are almost always composed of diabase and most often are associated with flood basalts of large igneous provinces . They are characteristic of divergent plate boundaries . For example, Jurassic dike swarms in New England and Paleogene swarms in

4536-483: The center of the rift zone before abruptly dropping to very few dikes. It is likely that the number of dikes must increase with depth, reaching a typical value of 300 to 350 per kilometer at the level of the ocean floor. In some respects, these dike swarms resemble those of western Scotland associated with the flood eruptions that preceded the opening of the Atlantic Ocean. Dikes often form as radial swarms from

4617-422: The continental United States, though only for use by members of its defense forces). The next-smallest topographic series, in terms of scale, is the 1:100,000 series. These maps are bounded by two lines of longitude and two lines of latitude. However, in this series, the lines of latitude are spaced 30 minutes apart and the lines of longitude are spaced 60 minutes, which is the source of another name for these maps;

4698-438: The dike is described as a multiple dike . However, subsequent injections are sometimes quite different in composition, and then the dike is described as a composite dike . The range of compositions in a composite dike can go all the way from diabase to granite , as is observed in some dikes of Scotland and northern Ireland. After the initial formation of a dike, subsequent injections of magma are most likely to take place along

4779-406: The disciplines of biology , geography , geology , and hydrology . The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources , and the natural hazards that threaten it. The agency also makes maps of extraterrestrial planets and moons based on data from U.S. space probes . The sole scientific agency of the U.S. Department of the Interior, USGS

4860-420: The distribution and severity of Shaking resulting from Earthquakes. 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 (both in terms of scale and quantity) and best-known topographic series is the 7.5-minute, 1:24,000 scale, quadrangle ,

4941-488: 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 (166 km ). At 49° north latitude, 49 square miles (127 km ) are contained within a quadrangle of that size. As a unique non-metric map scale, the 1:24,000 scale naturally requires a separate and specialized romer scale for plotting map positions. In recent years, budget constraints have forced

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5022-415: The long axis of the volcanic shield. Sills and stocks are occasionally present in the complexes. They are abruptly truncated at the margins of summit calderas. Typically, there are about 50 to 100 dikes per kilometer at the center of the rift zone, though the density can be as high as 500 per kilometer and the dikes then make up half the volume of the rock. The density drops to 5 to 50 per kilometer away from

5103-688: The magma fractured and disintegrated the rock at its advancing tip rather than prying the rock apart. Other dikes may have formed by metasomatism , in which fluids moving along a narrow fissure changed the chemical composition of the rock closest to the fissure. There is an approximate relationship between the width of a dike and its maximum extent, expressed by the formula: 2 w 2 b = 2.25 P e x ρ h o s t V P 2 {\displaystyle {\frac {2w}{2b}}={\frac {2.25P_{ex}}{\rho _{host}V_{P}^{2}}}} Here w {\displaystyle w}

5184-401: The margins. Here the dike rock fractures into columns as it cools and contracts. These are usually 5- to 6-sided, but 3- to 4-sided columns are also common. These are fairly uniform in size within a single dike, but range from a few centimeters to over 0.3 meters across in different dikes, tending to be thicker in wider dikes. Larger columns are likely a consequence of slower cooling. Dike rock

5265-545: The mission needs of the USGS. For instrument needs not currently met by a vendor, the Engineering Group designs, tests, and issues contracts to have HIF-designed equipment made. Sometimes HIF will patent a new design in the hope that instrument vendors will buy the rights and mass-produce the instrument at a lower cost to everyone. USGS researchers publish the results of their science in a variety of ways, including peer-reviewed scientific journals as well as in one of

5346-455: The national domain". The legislation also provided that the Hayden , Powell , and Wheeler surveys be discontinued as of June 30, 1879. Clarence King , the first director of USGS, assembled the new organization from disparate regional survey agencies. After two years, King was succeeded by John Wesley Powell . Dike (geology) In geology , a dike or dyke is a sheet of rock that

5427-465: The newest generation digital topo maps, including windmills, mines and mineshafts, water tanks, fence lines, survey marks, parks, recreational trails, buildings, boundaries, pipelines, telephone lines, power transmission lines, and even railroads. Additionally, the digital map's use of existing software may not properly integrate different feature classes or prioritize and organize text in areas of crowded features, obscuring important geographic details. As

5508-514: The northern part of the mountains were outside the reservation boundaries as reduced following a series of treaties in the late 19th century, but a trade of land now in Mesa Verde National Park, approximately 15 miles (24 km) east, for federal land on the mountain, allowed the reservation boundary to be extended north to McElmo Creek and encompass the entire mountain range. In particular, this means that recreational access to

5589-469: The onshore and offshore geologic framework; assess mineral resources and develop techniques for their discovery; assess water resources and develop an understanding of the impact of human activities and natural phenomena on hydrologic systems; assess links between biodiversity, habitat condition, ecosystem processes and health; and develop new technologies for collection and interpretation of earth science data. The USGS National Geomagnetism Program monitors

5670-428: The primary topographic quadrangle for the state of Alaska (and only for that particular state). Nearly 3,000 maps cover 97% of the state. The United States remains virtually the only developed country in the world without a standardized civilian topographic map series in the standard 1:25,000 or 1:50,000 metric scales, making coordination difficult in border regions (the U.S. military does issue 1:50,000 scale topo maps of

5751-523: The profile include the following (north to south): The illusion of a reclining figure is further reinforced by its symmetry. The figure is nearly as complete seen from the west as from the east. Though on the southwestern fringe of the original Rocky Mountain home of the Ute Tribe , the Sleeping Ute is the most prominent feature of the high-desert Ute Mountain Ute Reservation. The only town on

5832-417: The range by outsiders is severely restricted. Few roads or trails are found in the mountains, although radio towers and water tanks have been built, and a road along Cottonwood Wash from Towaoc nearly reaches the summit of Ute Peak. A Ute Indian legend describes the Sleeping Ute as the sleeping form of a "Great Warrior God who was also known as a chief" who fell asleep while recovering from wounds received in

5913-431: The rock, always opening a path along a plane normal to the minimum principal stress . This is the direction in which the crust is under the weakest compression and so requires the least work to fracture. At shallow depths, where the rock is brittle, the pressurized magma progressively fractures the rock as it advances upwards. Even if the magma is only slightly pressurized compared with the surrounding rock, tremendous stress

5994-429: The sea floor is underlain by sheeted dike complexes that preserve the conduits through which magma reached the ocean floor at mid-ocean ridges . These sheeted dikes characteristically show a chilled margin on only one side, indicating that each dike was split in half by a subsequent eruption of magma. Ring dikes and cone sheets are special types of dikes associated with caldera volcanism. These are distributed around

6075-532: The sequence of strata through which the dike propagates so that the dike becomes horizontal. It is common for a set of dikes, each a few kilometers long, to form en echelon . This pattern is seen in the Higganum dike set of New England. This dike set consists of individual dikes that are typically four kilometers in length at the surface and up to 60 meters wide. These short segments form longer groups extending for around 10 km. The entire set of dikes forms

6156-569: The sides of the dike. At depths where the rock is completely plastic, a diapir (a rising plug of magma) forms instead of a dike. The walls of dikes often fit closely back together, providing strong evidence that the dike formed by dilatation of a fissure. However, a few large dikes, such as the 120-meter-thick Medford dike in Maine, US, or the 500-meter-thick Gardar dike in Greenland, show no dilatation. These may have formed by stoping , in which

6237-535: The soft lower unit of the Entrada weathers into characteristic rounded forms, commonly called hoodoos . The underlying Navajo weathers into rough, rounded surfaces, commonly pitted, and usually forms cliffs. United States Geological Survey The United States Geological Survey ( USGS ), founded as the Geological Survey , is an agency of the U.S. Department of the Interior whose work spans

6318-469: The surface. They are studied by geologists for the clues they provide on volcanic plumbing systems . They also record ancient episodes of extension of the Earth's crust , since large numbers of dikes ( dike swarms ) are formed when the crust is pulled apart by tectonic forces. The dikes show the direction of extension, since they form at right angles to the direction of maximum extension. The thickness of

6399-400: The walls of dikes even when the walls consist of highly porous volcanic clinker, and little wall material breaks off into the molten magma. These fissures likely open as a result of bulging of the rock beds above a magma chamber that is being filled with magma from deeper in the crust. However, open fractures can exist only near the surface. Magma deeper in the crust must force its way through

6480-493: The west of Scotland and running into northern England record the early opening of the Atlantic Ocean. Dike swarms are forming in the present day along the divergent plate boundary running through Iceland. Dike swarms often have a great cumulative thickness: Dikes in Iceland average 3 to 5 meters in width, but one 53-kilometer stretch of coast has about 1000 dikes with total thickness of 3 kilometers. The world's largest dike swarm

6561-625: Was "Earth Science in the Public Service". Since 2012, the USGS science focus has been directed at topical "Mission Areas" that have continued to evolve. Further organizational structure includes headquarters functions, geographic regions, science and support programs, science centers, labs, and other facilities. The USGS regional organization aligns with the U.S. Department of the Interior Unified Interior Regions: USGS operates and organizes within

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