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Geology Of Bedford County, Pennsylvania
Bedford County, Pennsylvania is situated along the western border of the Ridge and Valley physiographic province, which is characterized by folded and faulted sedimentary rocks of early to middle Paleozoic age. The northwestern border of the county is approximately at the Allegheny Front, a geological boundary between the Ridge and Valley Province and the Allegheny Plateau (characterized by relatively flat-lying sedimentary rocks of late Paleozoic age).PA Geological Survey Map 13 The stratigraphic record of sedimentary rocks within the county spans from the Cambrian Warrior Formation to the Pennsylvanian Conemaugh Group (in the Broad Top area). No igneous or metamorphic rocks of any kind exist within the county. The primary mountains within the county (From west to east: Wills, Evitts, Dunning, and Tussey mountains) extend from the southern border with Maryland to the northeast into Blair County, and are held up by the Silurian Tuscarora Formation, made of qua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stratigraphy
Stratigraphy is a branch of geology concerned with the study of rock layers ( strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age). Historical development Catholic priest Nicholas Steno established the theoretical basis for stratigraphy when he introduced the law of superposition, the principle of original horizontality and the principle of lateral continuity in a 1669 work on the fossilization of organic remains in layers of sediment. The first practical large-scale application of stratigraphy was by William Smith in the 1790s and early 19th century. Known as the "Father of English geology", Smith recognized the significance of strata or rock layering and the importance of fossil markers for correlating strata; he created the first geol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Silurian
The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozoic Era. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by a few million years. The base of the Silurian is set at a series of major Ordovician–Silurian extinction events when up to 60% of marine genera were wiped out. One important event in this period was the initial establishment of terrestrial life in what is known as the Silurian-Devonian Terrestrial Revolution: vascular plants emerged from more primitive land plants, dikaryan fungi started expanding and diversifying along with glomeromycotan fungi, and three groups of arthropods ( myriapods, arachnids and hexapods) became fully terrestrialized. A significant evolutionary milestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blair County, Pennsylvania
Blair County is a county in the Commonwealth of Pennsylvania. As of the 2020 census, the population was 122,822. Its county seat is Hollidaysburg. The county was created on February 26, 1846, from parts of Huntingdon and Bedford counties. Blair County comprises the Altoona, PA metropolitan statistical area. It is also part of the Altoona-Huntingdon, PA Combined Statistical Area, which includes Blair and Huntingdon counties. Geography According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.2%) is water. Features * Brush Mountain * Logan Valley * Morrison Cove *Tussey Mountain Adjacent counties *Centre County (north) *Huntingdon County (east) * Bedford County (south) * Cambria County (west) *Clearfield County (northwest) National protected area * Allegheny Portage Railroad National Historic Site (part) Major highways * * * * * * * * * * * * * Climate Blair has a warm-summer humid continental climate (''Dfb''). Demographics As o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to its east. Baltimore is the largest city in the state, and the capital is Annapolis. Among its occasional nicknames are '' Old Line State'', the ''Free State'', and the '' Chesapeake Bay State''. It is named after Henrietta Maria, the French-born queen of England, Scotland, and Ireland, who was known then in England as Mary. Before its coastline was explored by Europeans in the 16th century, Maryland was inhabited by several groups of Native Americans – mostly by Algonquian peoples and, to a lesser degree, Iroquoian and Siouan. As one of the original Thirteen Colonies of England, Maryland was founded by George Calvert, 1st Baron Baltimore, a Catholic convert"George Calvert and Cecilius Calvert, Barons Baltimore" William Hand Browne, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tussey Mountain
Tussey Mountain is a stratigraphic ridge in central Pennsylvania, United States, trending east of the Bald Eagle, Brush, Dunning and Evitts Mountain ridges. Its southern foot just crosses the Mason–Dixon line near Flintstone, Maryland, running north 130 km (80 mi) to the Seven Mountains of central Pennsylvania, near Tusseyville, making it one of the longest named ridges in this section of the Ridge-and-valley Appalachians. The ridge line separates Morrison Cove from the Woodcock Valley and Friends Cove from the Black Valley. Tussey Mountain lies in, and the ridge line forms parts of the borders of, Centre, Blair, Bedford and Huntingdon counties. The Flintstone Creek runs around the southern end of the mountain in Maryland. North of there, small streams run through deep gorges, the Sweet Root and Rainsburg Gaps, near Martin Hill. At Everett the Pennsylvania Turnpike, U.S. Route 30, and the abandoned Huntingdon and Broad Top Mountain Railroad follow the Rays ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dunning Mountain
Dunning Mountain is a stratigraphic ridge in central Pennsylvania, United States. The mountain's north end is at McKee Gap, which separates it from Short Mountain, and where Halter Creek flows westward towards the Frankstown Branch of the Juniata River. The south end of the mountain is contiguous with Evitts Mountain, but is marked by a sharp bend to the east. The valley formed by the bend is known as "The Kettle," and the broad valley to the east of Dunning Mountain is called Morrisons Cove. The town of Roaring Spring is located at the north end of the mountain on the east side.https://viewer.nationalmap.gov/advanced-viewer/ The National Map, retrieved 13 November 2018Pennsylvania State Game Lands Number 147 retrieved 14 November 2018 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evitts Mountain
Evitts Mountain is a stratigraphic ridge in the Ridge and Valley region of the Appalachian Mountains, located in Bedford County, Pennsylvania, and Allegany County, Maryland. Geography The ridge line runs north from Rocky Gap State Park in Maryland, across the Mason–Dixon line into Pennsylvania and then to the west Martin Hill, passing very near Tussey Mountain in Snake Spring Valley. The ridge then turns west, wrapping around north of Bedford, Pennsylvania to its intersection with Dunning Mountain, dividing Dunning Cove from Morrison Cove. The Raystown Branch Juniata River passes through "The Narrows", a prominent water gap along with the Pennsylvania Turnpike and the now dismantled Bedford and Bridgeport Railroad near Bedford, Pennsylvania. Evitts Creek runs through the base of the Mountain in Rocky Gap State Park Rocky Gap State Park is a public recreation area with resort features located on Interstate 68 (exit 50), east of Cumberland in Allegany County, Marylan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wills Mountain
Wills Mountain is a quartzite-capped ridge in the Ridge and Valley physiographic province of the Appalachian Mountains in Pennsylvania and Maryland, United States, extending from near Bedford, Pennsylvania, to near Cumberland, Maryland. It is the northernmost of several mountain ridges included within the Wills Mountain Anticline. Geography Pennsylvania The Pennsylvania part of Wills Mountain is in Bedford County, reaching an elevation of . Although there are mountains in Pennsylvania's Appalachian Plateau that are higher, Wills Mountain is the highest in its Ridge and Valley physiographic province. Wills Mountain may have the highest prominence in Pennsylvania. The mountain ridge begins abruptly near the Juniata River just north of Kinton Knob, west of Bedford, and just south of the Pennsylvania Turnpike. The valley to the south of Kinton Knob is known as Milligans Cove, an excellent geological example of a breached anticline. Portions of Wills Mountain, including the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphic Rock
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causing profound physical or chemical changes. During this process, the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary, or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's land surface. They are classified by their protolith, their chemical and mineral makeup, and their texture. They may be formed simply by being deeply buried beneath the Earth's surface, where they are subject to high temperatures and the great pressure of the rock layers above. They can also form from tectonic processes such as continental collisions, which cause horizontal pressure, friction, and dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet's mantle or crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms, orogens, basins, large igneous provinces, extended crust and oceanic crust. Geological significance Igneous and metamorphic rocks make up 90–95% of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
