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Tuscarora Formation
The Silurian Tuscarora Formation — also known as Tuscarora Sandstone or Tuscarora Quartzite — is a mapped bedrock unit in Pennsylvania, Maryland, West Virginia, and Virginia, USA. Description The Tuscarora is a thin- to thick-bedded fine-grained to coarse-grained orthoquartzite. It is a white to medium-gray or gray-green subgraywacke, sandstone, siltstone and shale, cross-stratified and conglomeratic conglomerate in parts, containing a few shale interbeds.Berg, T.M., Edmunds, W.E., Geyer, A.R. and others, compilers, (1980). Geologic Map of Pennsylvania: Pennsylvania Geologic Survey, Map 1, scale 1:250,000. Details of the type locality and of stratigraphic nomenclature for this unit as used by the U.S. Geological Survey are available on-line at the National Geologic Map Database. The Tuscarora and its lateral equivalents are the primary ridge-formers of the Ridge-and-Valley Appalachians in the eastern United States It is typically 935 feet thick in Pennsylvania, and in Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centre County, Pennsylvania
Centre County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 158,172. Its county seat is Bellefonte. Centre County comprises the State College, PA Metropolitan Statistical Area. History The lands of the future Centre County were first recorded by James Potter in 1764. Potter, having reached the top of Nittany Mountain, and "....seeing the prairies and noble forest beneath him, cried out to his attendant, 'By heavens, Thompson, I have discovered an empire!'" After the American Revolutionary War, Centre County was created on February 13, 1800, from parts of Huntingdon, Lycoming, Mifflin, and Northumberland counties; it was named for its central location in the state. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.3%) is water. It is the fifth-largest county in Pennsylvania by area and uses area code 814. Centre has a humid continental climate which is warm-summer (''D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgraywacke
Greywacke or graywacke (German ''grauwacke'', signifying a grey, earthy rock) is a variety of sandstone generally characterized by its hardness, dark color, and poorly sorted angular grains of quartz, feldspar, and small rock fragments or lithic fragments set in a compact, clay-fine matrix. It is a texturally immature sedimentary rock generally found in Paleozoic strata. The larger grains can be sand- to gravel-sized, and matrix materials generally constitute more than 15% of the rock by volume. The term "greywacke" can be confusing, since it can refer to either the immature (rock fragment) aspect of the rock or its fine-grained (clay) component. The origin of greywacke was unknown until turbidity currents and turbidites were understood, since, according to the normal laws of sedimentation, gravel, sand and mud should not be laid down together. Geologists now attribute its formation to submarine avalanches or strong turbidity currents. These actions churn sediment and cause mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiographic Province
physiographic province is a geographic region with a characteristic geomorphology, and often specific subsurface rock type or structural elements. The continents are subdivided into various physiographic provinces, each having a specific character, relief, and environment which contributes to its distinctiveness. The physiographic provinces are then subdivided into smaller physiographic sections. Examples In eastern North America, the Atlantic Coastal Plain, Piedmont, Blue Ridge Mountains, Ridge-and-Valley Appalachians, and Appalachian Plateau are specific physiographic provinces. In the Western United States of western North America: the Basin and Range Province, Cascade Range, Colorado Plateau, Rio Grande rift, Great Basin, Central Valley (California), Peninsular Ranges, Los Angeles Basin, and Transverse Ranges are examples of physiographic provinces. See also * Physiographic provinces — index * Physiographic sections — index * Physiographic regions of the world — ''cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridge And Valley
The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending from southeastern New York in the north through northwestern New Jersey, westward into Pennsylvania through the Lehigh Valley, and southward into Maryland, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. They form a broad arc between the Blue Ridge Mountains and the Appalachian Plateau physiographic province (the Allegheny and Cumberland plateaus). They are characterized by long, even ridges, with long, continuous valleys in between. The river valleys were areas of indigenous settlements for thousands of years. In the historic period, the Cherokee people had towns along many of the rivers in western South Carolina and North Carolina, as well as on the western side of the Appalachian Mountains in present-day Tennessee. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Gap
A water gap is a gap that flowing water has carved through a mountain range or mountain ridge and that still carries water today. Such gaps that no longer carry water currents are called wind gaps. Water gaps and wind gaps often offer a practical route for road and rail transport to cross the mountain barrier. Geology A water gap is usually an indication of a river that is older than the current topography. The likely occurrence is that a river established its course when the landform was at a low elevation, or by a rift in a portion of the crust of the earth having a very low stream gradient and a thick layer of unconsolidated sediment. In a hypothetical example, a river would have established its channel without regard for the deeper layers of rock. A later period of uplift would cause increased erosion along the riverbed, exposing the underlying rock layers. As the uplift continued, the river, being large enough, would continue to erode the rising land, cutting thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goddard Space Flight Center
The Goddard Space Flight Center (GSFC) is a major NASA space research laboratory located approximately northeast of Washington, D.C. in Greenbelt, Maryland, United States. Established on May 1, 1959 as NASA's first space flight center, GSFC employs approximately 10,000 civil servants and contractors. It is one of ten major NASA field centers, named in recognition of American rocket propulsion pioneer Robert H. Goddard. GSFC is partially within the former Goddard census-designated place; it has a Greenbelt mailing address.CENSUS 2000 BLOCK MAP: GODDARD CDP " . Retrieved on September 1, 2018. 1990 Census map of Prince ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridge-and-Valley Appalachians
The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending from southeastern New York in the north through northwestern New Jersey, westward into Pennsylvania through the Lehigh Valley, and southward into Maryland, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. They form a broad arc between the Blue Ridge Mountains and the Appalachian Plateau physiographic province (the Allegheny and Cumberland plateaus). They are characterized by long, even ridges, with long, continuous valleys in between. The river valleys were areas of indigenous settlements for thousands of years. In the historic period, the Cherokee people had towns along many of the rivers in western South Carolina and North Carolina, as well as on the western side of the Appalachian Mountains in present-day Tenness ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ridge-former
A cliff-former is a geological unit of bedrock that is more resistant to erosion than overlying or underlying strata and consequently produces outcrops with high slope angles. It is more or less equivalent to ''ridge-former'', and may be contrasted with slope-former. In humid environments, sandstones are typically cliff-formers. In arid environments, limestones are often cliff-formers also. Recent lavas may be cliff-formers as well. In the Ridge-and-Valley Appalachians of the eastern United States the major ridge-formers are the Tuscarora, Pocono, and Pottsville Pottsville usually refers to the city of Pottsville, Pennsylvania, in the United States. Pottsville may also refer to: Other communities *Pottsville, New South Wales, Australia *Pottsville, Arkansas, United States *Pottsville, Kentucky, United ... Formations. References {{geomorph-stub Erosion landforms Geomorphology ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvania Geological Survey
The Pennsylvania Geological Survey or Bureau of Topographic and Geologic Survey (BTGS), is a geological survey enacted by the Pennsylvania General Assembly "to serve the citizens of Pennsylvania by collecting, preserving, and disseminating impartial information on the Commonwealth's geology, geologic resources, and topography in order to contribute to the understanding, wise use, and conservation of its land and included resources." The geological survey operates under the Pennsylvania Department of Conservation and Natural Resources. History In total, four surveys have been conducted in the commonwealth. The first survey was created in 1836, making it one of the oldest geological survey A geological survey is the systematic investigation of the geology beneath a given piece of ground for the purpose of creating a geological map or model. Geological surveying employs techniques from the traditional walk-over survey, studying outc ...s in the United States. It was followed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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