Geology of Washington, D.C.

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The Geology of Washington, D.C., is broadly divisible into two regions. [1] The northwestern quadrant of the city lies mainly in the Appalachian Piedmont region, [1] 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. [1] 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.

Appalachian Mountains mountain range in the eastern United States and Canada, and France

The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern 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.

Piedmont (United States) plateau region located in the eastern United States

The Piedmont is a plateau region located in the Eastern United States. It sits between the Atlantic coastal plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south. The Piedmont Province is a physiographic province of the larger Appalachian division which consists of the Gettysburg-Newark Lowlands, the Piedmont Upland and the Piedmont Lowlands sections.

The Ordovician is a geologic period and system, the second of six periods of the Paleozoic Era. The Ordovician spans 41.2 million years from the end of the Cambrian Period 485.4 million years ago (Mya) to the start of the Silurian Period 443.8 Mya.

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 coming up the river. [1] (See also Atlantic Seaboard fall line.) Below Roosevelt Island, the Potomac spills out onto the Coastal Plain, leaving the rock formations of Great Falls and the rocky cliffs of the Arlington, Virginia shore behind as it slows and widens. The Tidal Basin and the Washington Channel are part of this wider section of the river. Much of the National Mall was marsh in the early Nineteenth century; as the capital city grew, the marsh was filled in and reclaimed.

George Washington First President of the United States

George Washington was an American political leader, military general, statesman, and Founding Father who served as the first president of the United States from 1789 to 1797. He led Patriot forces to victory in the nation's War for Independence. He presided at the Constitutional Convention of 1787 which established the U.S. Constitution and a federal government. Washington has been called the "Father of His Country" for his manifold leadership in the formative days of the new nation.

A fall line 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. Because of the need for a river port leading to the ocean, and a ready supply of water power, settlements often develop where rivers cross a fall line.

Potomac River river in the mid-Atlantic United States

The Potomac River is found within the Mid-Atlantic region of the United States and flows from the Potomac Highlands into the Chesapeake Bay. The river is approximately 405 miles (652 km) long, with a drainage area of about 14,700 square miles (38,000 km2). In terms of area, this makes the Potomac River the fourth largest river along the Atlantic coast of the United States and the 21st largest in the United States. Over 5 million people live within the Potomac watershed.

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East Coast of the United States Coastline in the United States

The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the coastline along which the Eastern United States meets the North Atlantic Ocean. The coastal states that have shoreline on the Atlantic Ocean are, from north to south, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida.

Tidewater (region)

Tidewater is a reference to the Atlantic coastal plain region of the United States of America. It includes the low-lying plains of southeast Virginia, northeastern North Carolina, southern Maryland and the Chesapeake Bay. The area got its name from the effects of the changing tides on local rivers, sounds, and the ocean; there is also a cultural heritage that sets the Tidewater regions apart from other parts of the United States. Tidewater region was founded on principles of English gentry in a developing nation where patriotism, freedom and waterborne livelihoods existed. Dialects are distinctive and eroding along with islands and shoreline.

Geography of North Carolina

The geography of North Carolina falls naturally into three divisions — the Appalachian Mountains in the west, the central Piedmont Plateau, and the eastern Atlantic Coastal Plain. North Carolina covers 53,821 square miles (139,396 km2) and is 503 miles (810 km) long by 150 miles (241 km) wide. The physical characteristics of the state can be pictured as a surface spread out upon a vast declivity, sloping down from the summits of the Smoky Mountains, an altitude of near seven thousand feet (2,130 m), to the ocean level.

Atlantic coastal plain physiographic region along the East Coast of the United States

The Atlantic coastal plain is a physiographic region of low relief along the East Coast of the United States. It extends 2,200 miles (3,500 km) from the New York Bight southward to a Georgia/Florida section of the Eastern Continental Divide, which demarcates the plain from the ACF River Basin in the Gulf Coastal Plain to the west. The province is bordered on the west by the Atlantic Seaboard fall line and the Piedmont plateau, to the east by the Atlantic Ocean, and to the south by the Floridian province. The Outer Lands archipelagic region forms the insular northeasternmost extension of the Atlantic coastal plain.

Theodore Roosevelt Island island and a national memorial located in the Potomac River in Washington, D.C.

Theodore Roosevelt Island is an 88.5-acre (358,000 m2) island and national memorial located in the Potomac River in Washington, D.C. The island was given to the Federal government by the Theodore Roosevelt Association in memory of the 26th president, Theodore Roosevelt. Until then, the island had been known as My Lord's Island, Barbadoes Island, Mason's Island, Analostan Island, and Anacostine Island.

Ogeechee River

The Ogeechee River is a 294-mile-long (473 km) blackwater river in the U.S. state of Georgia. It heads at the confluence of its North and South Forks, about 2.5 miles (4.0 km) south-southwest of Crawfordville and flowing generally southeast to Ossabaw Sound about 16 miles (26 km) south of Savannah. Its largest tributary is the Canoochee River, which drains approximately 1,400 square miles (3,600 km2) and is the only other major river in the basin. The Ogeechee has a watershed of 5,540 square miles (14,300 km2). It is one of the state's few free-flowing streams.

Geography of New Jersey

New Jersey is a state within the United States of America that lies on the north eastern edge of the North American continent. It shares a land border with the state of State of New York along the north, ratified by both states after the New York – New Jersey Line War. New Jersey is slightly larger than the country of Kuwait.

Geology of Georgia (U.S. state)

The Geology of Georgia consists of four distinct geologic regions, beginning in the northwest corner of the state and moving through the state to the southeast: the Valley and Ridge region, also known as the Appalachian Plateau; the Blue Ridge; the Piedmont and the Coastal Plain. The Fall Line is the boundary between the Piedmont and the Coastal Plain.

Geology of Pennsylvania

The Geology of Pennsylvania consists of six distinct physiographic provinces, three of which are subdivided into different sections. Each province has its own economic advantages and geologic hazards and plays an important role in shaping everyday life in the state. They are: the Atlantic Coastal Plain Province, the Piedmont Province, the New England Province, the Ridge and Valley Province, the Appalachian Plateau Province, and the Central Lowlands Province.

Geology of Delaware

The geology of Delaware consists of two physiographic provinces located in the U.S. state of Delaware. They are the Atlantic Coastal Plain and the Piedmont.

Outline of Washington, D.C. Overview of and topical guide to Washington, D.C.

The following outline is provided as an overview of and topical guide to Washington, D.C.:

Northwest Branch Anacostia River tributary of the Anacostia River River, in Montgomery and Prince George’s counties, Maryland, United States

Northwest Branch Anacostia River is a 21.5-mile-long (34.6 km) free-flowing stream in Montgomery County and Prince George's County, Maryland. It is a tributary of the Anacostia River, which flows to the Potomac River and the Chesapeake Bay.

Environment of Virginia

The natural environment of Virginia encompasses the physical geography and biology of the U.S. state of Virginia. Virginia has a total area of 42,774.2 square miles (110,784.67 km2), including 3,180.13 square miles (8,236.5 km2) of water, making it the 35th-largest state by area. Forests cover 65% of the state, wetlands and water cover 6% of the land in the state, while 5% of the state is a mixture of commercial, residential, and transitional.

The Geographical Regions of South Carolina refers to the four major geographical regions of South Carolina. The largest region in the state is the Piedmont located between the Mountains and the Carolina Sandhills, while the smallest in region in the state is the Mountains also known as the Blue Ridge Range.

Atlantic Seaboard fall line escarpment in the Eastern United States

The Atlantic Seaboard Fall Line, or Fall Zone, is a 900-mile (1,400 km) escarpment where the Piedmont and Atlantic coastal plain meet in the eastern United States. Much of the Atlantic Seaboard fall line passes through areas where no evidence of faulting is present.

Little Falls (Potomac River) waterfall in Washington D.C.

Little Falls is an area of rapids located where the Potomac River crosses the Atlantic Seaboard fall line, descending from the harder and older rocks of the Piedmont Plateau to the softer sediments of the Atlantic coastal plain. Situated at the point where Washington, DC, Maryland and Virginia meet, it is the first "cataract", or barrier, to navigation encountered on the Potomac River when going upstream. It may be viewed from the heavily trafficked Chain Bridge, about a half mile upstream. It is named in contradistinction to Great Falls, about 5 miles further upstream.

References

  1. 1 2 3 4 Means, John (2010). Roadside Geology of Maryland, Delaware, and Washington, D.C. Missoula, Montana: Mountain Press. ISBN   978-0-87842-570-9.
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