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Culpeper Basin
The Culpeper Basin is one of the Newark Supergroup's Triassic rift basins. It lies east of the Appalachian Mountains and extends from the Madison County—Orange County line in Virginia to Frederick, Maryland.Bedrock map and geotechnical properties of rocks of the Culpeper basin, Virginia and Maryland Leavy, B.D., Froelich, A.J., and Abram, E.C. Miscellaneous Investigations Series Map I-1313-C. 1983. Map Scale: 1:125,000. A diverse group of sedimentary rocks including , , and [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bedrock Map Culpeper Basin (Leavy, Froelich, Abram) 1983
In geology, bedrock is solid rock that lies under loose material (regolith) within the crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface material. An exposed portion of bedrock is often called an outcrop. The various kinds of broken and weathered rock material, such as soil and subsoil, that may overlie the bedrock are known as regolith. Engineering geology The surface of the bedrock beneath the soil cover (regolith) is also known as ''rockhead'' in engineering geology, and its identification by digging, drilling or geophysical methods is an important task in most civil engineering projects. Superficial deposits can be very thick, such that the bedrock lies hundreds of meters below the surface. Weathering of bedrock Exposed bedrock experiences weathering, which may be physical or chemical, and which alters the structure of the rock to leave it susceptible to erosion. Bedrock may also experience subsurfac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabase
Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French ', and ultimately from the Greek - meaning "act of crossing over, transition". Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a finer matrix of clinopyroxene, typically augite (20–29%), with minor olivine (3% up to 12% in olivine diabase), magnetite (2%), an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dulles International Airport
Washington Dulles International Airport , typically referred to as Dulles International Airport, Dulles Airport, Washington Dulles, or simply Dulles ( ), is an international airport in the Eastern United States, located in Loudoun County and Fairfax County in Virginia, west of Downtown , and away from Ronald Reagan National Airport in Arlington County, Virginia. Opened in 1962, it is named after John Foster Dulles the 52nd U.S. Secretary of State who served under President Dwight D. Eisenhower. The Dulles main terminal is a well-known landmark designed by Eero Saarinen, who also designed the famous TWA Flight Center at John F. Kennedy International Airport. Operated by the Metropolitan Washington Airports Authority, Washington Dulles Airport occupies , straddling the Loudoun–Fairfax Most of the airport is in the unincorporated community of Dulles in Loudoun County, with a small portion in the unincorporated community of Chantilly in Fairfax County. Dulles is one of the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boyds, Maryland
Boyds is an unincorporated community in rural Montgomery County, Maryland, United States, located approximately north of Washington, D.C. Its ZIP Code is 20841. According to the United States 2010 Census, the ZIP Code Tabulation Area (ZCTA) for Boyds covers an area of about and has a population of 10,460. Black Hill Regional Park, Little Seneca Lake, and Seneca Creek State Park are located in Boyds. History The community was named for Colonel James Alexander Boyd (1823–1896), a Scottish immigrant who was a construction engineer for the Baltimore and Ohio Railroad. Boyd built a temporary village to house construction workers as the Baltimore and Ohio Railroad built the Metropolitan Branch line after the American Civil War. The railroad line began service in 1873. After the railroad station opened, a mill, stores, and other businesses were established in the area. The Baltimore and Ohio Railroad opened a brick railroad station in 1887. The railroad station was demolished ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sill (geology)
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A ''sill'' is a ''concordant intrusive sheet'', meaning that a sill does not cut across preexisting rock beds. Stacking of sills builds a sill complex . and a large magma chamber at high magma flux. In contrast, a dike is a discordant intrusive sheet, which does cut across older rocks. Sills are fed by dikes, except in unusual locations where they form in nearly vertical beds attached directly to a magma source. The rocks must be brittle and fracture to create the planes along which the magma intrudes the parent rock bodies, whether this occurs along preexisting planes between sedimentary or volcanic beds or weakened planes related to foliation in metamorphic rock. These planes or weakened areas allow the intrusion of a thin sheet-like body of magma paralleling the existing bedding pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montgomery County, Maryland
Montgomery County is the most populous county in the state of Maryland. As of the 2020 census, the county's population was 1,062,061, increasing by 9.3% from 2010. The county seat and largest municipality is Rockville, although the census-designated place of Germantown is the most populous place within the county. Montgomery County, which adjoins Washington, D.C., is part of the Washington–Arlington–Alexandria, DC–VA–MD–WV metropolitan statistical area, which in turn forms part of the Baltimore–Washington combined statistical area. Most of the county's residents live in unincorporated locales, of which the most urban are Silver Spring and Bethesda, although the incorporated cities of Rockville and Gaithersburg are also large population centers, as are many smaller but significant places. The average household income in Montgomery County is among the highest in the United States. It has the highest percentage (29.2%) of residents over 25 years of age who hold po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bull Run Formation
The Bull Run Formation is a Late Triassic ( Norian) stratigraphic unit in the eastern United States.Bull Run Formation at Fossilworks.org Fossil fish bones and scales have been found in outcrops of the formation's Groveton Member in .Hunt et al., 2006, p.64 Indeterminate fossil tracks have been reported from the formati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Groveton Member
Groveton may refer to a community in the United States: * Groveton, New Hampshire * Groveton, Texas * Groveton, Virginia Groveton is a census-designated place (CDP) in Fairfax County, Virginia, United States. The population was 14,598 at the 2010 census, down from 21,296 in 2000 due to a reduction in area. Located south of the city of Alexandria, it encompasses nume ... {{geodis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barboursville Basin
Barboursville is the name of several places in the United States of America: * Barboursville, Virginia * Barboursville, West Virginia * Barboursville (James Barbour) the Virginia home of James Barbour * Barboursville Vineyards Barboursville Vineyards is a winery located in the Piedmont region of the Commonwealth of Virginia in the unincorporated community of Barboursville, Virginia. It is located within both the Virginia and Monticello viticultural areas. History The ... a winery located in Orange County, Virginia See also * Barbourville (other) {{disambig, geodis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gettysburg Basin
Gettysburg may refer to: Events * Gettysburg Campaign, a series of American Civil War military engagements in the Main Eastern Theater. ** Battle of Gettysburg, July 1–3 military engagements during the 1863 Gettysburg Campaign ** Retreat from Gettysburg, the Confederate and Union armies' return to the South following the Battle of Gettysburg * Gettysburg Address, President Abraham Lincoln's speech at the November 19, 1863, Consecration of the National Cemetery at Gettysburg. Places ; Pennsylvania-related articles *Gettysburg, Pennsylvania ** Gettysburg Battlefield Historic District, of historic properties, buildings, and structures in Adams County, Pennsylvania ** Gettysburg National Military Park, protected by the National Park Service *** Gettysburg Museum and Visitor Center, the National Park Service's reception center *** Gettysburg National Cemetery, a district of the military park on Cemetery Hill *** Gettysburg National Museum, the 1921 museum used as the 1974-2008 NPS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphism
Metamorphism is the transformation of existing rock (the protolith) to rock with a different mineral composition or texture. Metamorphism takes place at temperatures in excess of , and often also at elevated pressure or in the presence of chemically active fluids, but the rock remains mostly solid during the transformation. Metamorphism is distinct from weathering or diagenesis, which are changes that take place at or just beneath Earth's surface. Various forms of metamorphism exist, including regional, contact, hydrothermal, shock, and dynamic metamorphism. These differ in the characteristic temperatures, pressures, and rate at which they take place and in the extent to which reactive fluids are involved. Metamorphism occurring at increasing pressure and temperature conditions is known as ''prograde metamorphism'', while decreasing temperature and pressure characterize ''retrograde metamorphism''. Metamorphic petrology is the study of metamorphism. Metamorphic petrologists re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conglomerate (geology)
Conglomerate () is a clastic sedimentary rock that is composed of a substantial fraction of rounded to subangular gravel-size clasts. A conglomerate typically contains a matrix of finer-grained sediments, such as sand, silt, or clay, which fills the interstices between the clasts. The clasts and matrix are typically cemented by calcium carbonate, iron oxide, silica, or hardened clay. Conglomerates form by the consolidation and lithification of gravel. They can be found in sedimentary rock sequences of all ages but probably make up less than 1 percent by weight of all sedimentary rocks. In terms of origin and depositional mechanisms, they are closely related to sandstones and exhibit many of the same types of sedimentary structures, e.g., tabular and trough cross-bedding and graded bedding.Boggs, S. (2006) ''Principles of Sedimentology and Stratigraphy.'', 2nd ed. Prentice Hall, New York. 662 pp. Friedman, G.M. (2003) ''Classification of sediments and sedimentary rocks.'' In G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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