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Geology Of Washington, D.C.
The Geology of Washington, D.C., is broadly divisible into two regions. The northwestern quadrant of the city lies mainly in the Appalachian Piedmont region, marked by moderate to steep hills underlain by metamorphic rocks of Ordovician through Devonian age, similar to the adjacent Piedmont regions of Montgomery County, Maryland. The National Mall, northeastern and southeastern quadrants of Washington lie in the mid-Atlantic Coastal Plain region, consisting of sedimentary deposits laid down during the much more recent Tertiary and Quaternary periods, like the bordering areas of southern Maryland. Some areas in Northeast and Southeast Washington also feature hilly terrain, especially east of the Anacostia River; this however stems from rivers and creeks down-cutting into the relatively soft soil. City founders George Washington and Pierre L'Enfant chose to locate the District of Columbia on the fall line of the Potomac River, the point furthest inland reachable by ships comi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Appalachian Mountains
The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They once reached elevations similar to those of the Alps and the Rocky Mountains before experiencing natural erosion. The Appalachian chain is a barrier to east–west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west. Definitions vary on the precise boundaries of the Appalachians. The United States Geological Survey (USGS) defines the ''Appalachian Highlands'' physiographic division as consisting of 13 provinces: the Atlantic Coast Uplands, Eastern Newfoundland Atlantic, Maritime Acadian Highlands, Maritime Plain, Notre Dame and Mégantic Mountains, Western Newfoundland Mountains, Piedmont, Blue Ridge, Valley and Ridge, St. Lawrence Valley, Appalac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre L'Enfant
Pierre "Peter" Charles L'Enfant (; August 2, 1754June 14, 1825) was a French-American military engineer who designed the basic plan for Washington, D.C. (capital city of the United States) known today as the L'Enfant Plan (1791). Early life and education L'Enfant was born in Paris, France, on August 2, 1754, as the third child and second son of Pierre L'Enfant (1704–1787), a painter and professor at Royal Academy of Painting and Sculpture known for his panoramas of battles, and Marie Leullier, the daughter of a French military officer. In 1758, his brother Pierre Joseph died at six, and Pierre Charles became the eldest son. He studied art at the Royal Academy from 1771 until 1776, when he left school in France to enlist in the American Revolutionary War on the side of the rebelling colonials. Military service L'Enfant was recruited by Pierre Augustin Caron de Beaumarchais to serve in the American Revolutionary War in the United States. He arrived in 1777 at the age of 23, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Washington, D
Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Earth sciences, including hydrology, and so is treated as one major aspect of integrated Earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, and the processes that have shaped that structure. It also provides tools to determine the relative and absolute ages of rocks found in a given location, and also to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, and also to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, and the Earth's past climates. Geologists broadly study the properties and processes of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marsh
A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at the edges of lakes and streams, where they form a transition between the aquatic and terrestrial ecosystems. They are often dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs, and the marsh is sometimes called a carr. This form of vegetation is what differentiates marshes from other types of wetland such as swamps, which are dominated by trees, and mires, which are wetlands that have accumulated deposits of acidic peat. Marshes provide habitats for many kinds of invertebrates, fish, amphibians, waterfowl and aquatic mammals. This biological productivity means that marshes contain 0.1% of global sequestered terrestrial carbon. Moreover, they have an outsized influence on climate resi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Washington Channel
The Washington Channel is a channel that parallels the Potomac River in Washington, D.C. It is located between the Southwest Waterfront on the east side and East Potomac Park on the west side. The channel is long, receives outflow from the Tidal Basin at its north end, and empties into the Anacostia River at Hains Point at its south end. The channel's depth ranges from to . The Washington Channel's east bank is lined with restaurants, inns, and marinas including Washington Marina, Gangplank Marina (the only liveaboard marina in the District of Columbia), and Capital Yacht Club. The Maine Avenue Fish Market is situated at the north end of the channel, south of the 14th Street Bridge complex. The Women's ''Titanic'' Memorial, Fort Lesley J. McNair, the National Defense University, and James Creek Marina are located near the south end of the channel. As of August 2010, USS ''Sequoia''—a former United States presidential yacht—is docked at a pier in the Washington Channel. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arlington, Virginia
Arlington County is a county in the Commonwealth of Virginia. The county is situated in Northern Virginia on the southwestern bank of the Potomac River directly across from the District of Columbia, of which it was once a part. The county is coextensive with the U.S. Census Bureau's census-designated place of Arlington. Arlington County is considered to be the second-largest "principal city" of the Washington metropolitan area, although Arlington County does not have the legal designation of independent city or incorporated town under Virginia state law. In 2020, the county's population was estimated at 238,643, making Arlington the sixth-largest county in Virginia by population; if it were incorporated as a city, Arlington would be the third most populous city in the state. With a land area of , Arlington is the geographically smallest self-governing county in the U.S., and by reason of state law regarding population density, it has no incorporated towns within its borders ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Falls (Potomac River)
Great Falls is a series of rapids and waterfalls on the Potomac River, upstream from Washington, D.C., on the border of Montgomery County, Maryland and Fairfax County, Virginia. Great Falls Park, managed as part of George Washington Memorial Parkway, is on the southern banks in Virginia, and Chesapeake and Ohio Canal National Historical Park parkland is along the northern banks of the river in Maryland. Both are operated by the National Park Service. The Potomac and the falls themselves are legally entirely within Maryland, with the state and county boundaries following the south bank of the river. Scenic views are offered on both the Maryland side and the Virginia side. The Billy Goat Trail on Bear Island, accessible from Maryland, offers scenic views of the Great Falls, as do vantage points on Olmsted Island (also accessible from Maryland). There are overlook points on the Virginia side. The Great Falls area is popular for outdoor activities such as kayaking, whitewater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roosevelt Island
Roosevelt Island is an island in New York City's East River, within the borough of Manhattan. It lies between Manhattan Island to the west, and the borough of Queens, on Long Island, to the east. Running from the equivalent of East 46th to 85th Streets on Manhattan Island, it is about long, with a maximum width of , and a total area of . Together with Mill Rock, Roosevelt Island constitutes Manhattan's Census Tract 238, which has a land area of , and had a population of 11,722 as of the 2020 United States Census. Lying below the Queensboro Bridge, the island cannot be accessed directly from the bridge itself. Vehicular traffic uses the Roosevelt Island Bridge to access the island from Astoria, Queens, though the island is not designed for vehicular traffic and has several areas designed as car-free zones. Several public transportation options to reach the island exist. The Roosevelt Island Tramway, the oldest urban commuter tramway in the U.S, connects the island to Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potomac River
The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved August 15, 2011 with a drainage area of 14,700 square miles (38,000 km2), and is the fourth-largest river along the East Coast of the United States and the 21st-largest in the United States. Over 5 million people live within its watershed. The river forms part of the borders between Maryland and Washington, D.C. on the left descending bank and between West Virginia and Virginia on the right descending bank. Except for a small portion of its headwaters in West Virginia, the North Branch Potomac River is considered part of Maryland to the low-water mark on the opposite bank. The South Branch Potomac River lies completely within the state of West Virginia except for its headwaters, which lie in Virginia. Course The Potomac River runs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fall Line
A fall line (or fall zone) is the area where an upland region and a coastal plain meet and is typically prominent where rivers cross it, with resulting rapids or waterfalls. The uplands are relatively hard crystalline basement rock, and the coastal plain is softer sedimentary rock. A fall line often will recede upstream as the river cuts out the uphill dense material, forming "c"-shaped waterfalls and exposing bedrock shoals. Because of these features, riverboats typically cannot travel any farther inland without portaging, unless locks are built. The rapid change in elevation of the water and resulting energy release make the fall line a good location for water mills, grist mills, and sawmills. Seeking a head of navigation with a ready supply of water power, people have long made settlements where rivers cross a fall line. Geography The slope of fall zones on rivers played a role in settlement patterns. For example, the fall line represents the inland limit of navigation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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