Atlantic Seaboard fall line
Encyclopedia
The Atlantic Seaboard Fall Line, or Fall Zone, is a 900 miles (1,448.4 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.
The fall line
marks the geologic boundary of hard metamorphosed terrain—the product of the Taconic orogeny
—and the sandy, relatively flat outwash plain of the upper continental shelf, formed of unconsolidated Cretaceous
and Tertiary
sediment
s. Examples of the Fall Zone include the Potomac River's Great Falls and the rapids in Richmond, Virginia
, where the James River
falls across a series of rapids down to the tidal estuary of the James River.
Before navigation improvements such as locks, the fall line was often the head of navigation on rivers due to rapids and waterfalls, such as the Great Falls of the Potomac River
. Numerous cities were founded at the intersection of rivers and the fall line. U.S. Route 1
links many of the fall line cities. Some of the cities along the Piedmont—Coastal Plain fall line include, from north to south:
Escarpment
An escarpment is a steep slope or long cliff that occurs from erosion or faulting and separates two relatively level areas of differing elevations.-Description and variants:...
where the Piedmont
Piedmont (United States)
The Piedmont is a plateau region located in the eastern United States 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...
and Atlantic coastal plain
Atlantic Coastal Plain
The Atlantic coastal plain has both low elevation and low relief, but it is also a relatively flat landform extending 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...
meet in the eastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Much of the Atlantic Seaboard fall line passes through areas where no evidence of faulting is present.
The fall line
Fall line
A fall line is a geomorphologic unconformity between an upland region of relatively hard crystalline basement rock and a coastal plain of softer sedimentary rock. A fall line is typically prominent when crossed by a river, for there will often be rapids or waterfalls...
marks the geologic boundary of hard metamorphosed terrain—the product of the Taconic orogeny
Taconic orogeny
The Taconic orogeny was a mountain building period that ended 440 million years ago and affected most of modern-day New England. A great mountain chain formed from eastern Canada down through what is now the Piedmont of the East coast of the United States...
—and the sandy, relatively flat outwash plain of the upper continental shelf, formed of unconsolidated Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
and Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s. Examples of the Fall Zone include the Potomac River's Great Falls and the rapids in Richmond, Virginia
Richmond, Virginia
Richmond is the capital of the Commonwealth of Virginia, in the United States. It is an independent city and not part of any county. Richmond is the center of the Richmond Metropolitan Statistical Area and the Greater Richmond area...
, where the James River
James River
The James River may refer to:Rivers in the United States and their namesakes* James River * James River , North Dakota, South Dakota* James River * James River * James River...
falls across a series of rapids down to the tidal estuary of the James River.
Before navigation improvements such as locks, the fall line was often the head of navigation on rivers due to rapids and waterfalls, such as the Great Falls of the Potomac River
Potomac River
The Potomac River flows into the Chesapeake Bay, located along the mid-Atlantic coast of the United States. The river is approximately long, with a drainage area of about 14,700 square miles...
. Numerous cities were founded at the intersection of rivers and the fall line. U.S. Route 1
U.S. Route 1
U.S. Route 1 is a major north–south U.S. Highway that serves the East Coast of the United States. It runs 2,377 miles from Fort Kent, Maine at the Canadian border south to Key West, Florida. U.S. 1 generally parallels Interstate 95, though it is significantly farther west between...
links many of the fall line cities. Some of the cities along the Piedmont—Coastal Plain fall line include, from north to south:
- Paterson, New JerseyPaterson, New JerseyPaterson is a city serving as the county seat of Passaic County, New Jersey, United States. As of the 2010 United States Census, its population was 146,199, rendering it New Jersey's third largest city and one of the largest cities in the New York City Metropolitan Area, despite a decrease of 3,023...
on the Passaic RiverPassaic RiverThe Passaic River is a mature surface river, approximately 80 mi long, in northern New Jersey in the United States. The river in its upper course flows in a highly circuitous route, meandering through the swamp lowlands between the ridge hills of rural and suburban northern New Jersey,... - Trenton, New JerseyTrenton, New JerseyTrenton is the capital of the U.S. state of New Jersey and the county seat of Mercer County. As of the 2010 United States Census, Trenton had a population of 84,913...
on the Delaware RiverDelaware RiverThe Delaware River is a major river on the Atlantic coast of the United States.A Dutch expedition led by Henry Hudson in 1609 first mapped the river. The river was christened the South River in the New Netherland colony that followed, in contrast to the North River, as the Hudson River was then...
. - Philadelphia, PennsylvaniaPhiladelphia, PennsylvaniaPhiladelphia is the largest city in the Commonwealth of Pennsylvania and the county seat of Philadelphia County, with which it is coterminous. The city is located in the Northeastern United States along the Delaware and Schuylkill rivers. It is the fifth-most-populous city in the United States,...
on the Schuylkill RiverSchuylkill RiverThe Schuylkill River is a river in Pennsylvania. It is a designated Pennsylvania Scenic River.The river is about long. Its watershed of about lies entirely within the state of Pennsylvania. The source of its eastern branch is in the Appalachian Mountains at Tuscarora Springs, near Tamaqua in...
. - Wilmington, DelawareWilmington, DelawareWilmington is the largest city in the state of Delaware, United States, and is located at the confluence of the Christina River and Brandywine Creek, near where the Christina flows into the Delaware River. It is the county seat of New Castle County and one of the major cities in the Delaware Valley...
on Brandywine Creek. - Newark, DelawareNewark, DelawareNewark is an American city in New Castle County, Delaware, west-southwest of Wilmington. According to the 2010 Census, the population of the city is 31,454. Newark is the home of the University of Delaware.- History :...
on the Christina RiverChristina RiverThe Christina River is a tributary of the Delaware River, approximately 35 miles long, in northern Delaware in the United States, also flowing through small areas of southeastern Pennsylvania and northeastern Maryland. Near its mouth the river flows past downtown Wilmington, Delaware,...
. - Stanton, DelawareStanton, DelawareStanton is an unincorporated community in New Castle County, Delaware, United States, near the confluence of the Red Clay and White Clay Creeks. It is located in the southern end of Mill Creek Hundred.-History:...
on the White Clay CreekWhite Clay CreekWhite Clay Creek is an tributary of the Christina River in southern Pennsylvania and northern Delaware in the United States. It is renowned for its scenic character and is largely federally protected....
. - BaltimoreBaltimoreBaltimore is the largest independent city in the United States and the largest city and cultural center of the US state of Maryland. The city is located in central Maryland along the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore...
, Maryland, on the Patapsco RiverPatapsco RiverThe Patapsco River is a river in central Maryland which flows into Chesapeake Bay. The river's tidal portion forms the harbor for the city of Baltimore...
. - Laurel, MarylandLaurel, MarylandLaurel is a city in northern Prince George's County, Anne Arundel County, and Howard County, Maryland, United States, located midway between Washington, D.C. and Baltimore. Incorporated in 1870, the city maintains a historic district including its Main Street...
on the Patuxent RiverPatuxent RiverThe Patuxent River is a tributary of the Chesapeake Bay in the state of Maryland. There are three main river drainages for central Maryland: the Potomac River to the west passing through Washington D.C., the Patapsco River to the northeast passing through Baltimore, and the Patuxent River between...
. - Georgetown, District of Columbia on the Potomac RiverPotomac RiverThe Potomac River flows into the Chesapeake Bay, located along the mid-Atlantic coast of the United States. The river is approximately long, with a drainage area of about 14,700 square miles...
. - Occoquan, VirginiaOccoquan, VirginiaOccoquan is a town in Prince William County in the U.S. state of Virginia. The population was 759 at the 2000 census, but as of the census of 2010, there were 934 people residing in the town of Occoquan. The town is a suburb of Washington, D.C. and is adjacent to Woodbridge...
on the Occoquan RiverOccoquan RiverThe Occoquan River is a tributary of the Potomac River in northern Virginia, in the mid-Atlantic region of the United States. The river is long, and its watershed covers about . It is formed by the confluence of Broad Run and Cedar Run in Prince William County; Bull Run enters it east-southeast of...
. - Fredericksburg, VirginiaFredericksburg, VirginiaFredericksburg is an independent city in the Commonwealth of Virginia located south of Washington, D.C., and north of Richmond. As of the 2010 census, the city had a population of 24,286...
on the Rappahannock RiverRappahannock RiverThe Rappahannock River is a river in eastern Virginia, in the United States, approximately in length. It traverses the entire northern part of the state, from the Blue Ridge Mountains in the west, across the Piedmont, to the Chesapeake Bay, south of the Potomac River.An important river in American...
. - Richmond, VirginiaRichmond, VirginiaRichmond is the capital of the Commonwealth of Virginia, in the United States. It is an independent city and not part of any county. Richmond is the center of the Richmond Metropolitan Statistical Area and the Greater Richmond area...
on the James RiverJames RiverThe James River may refer to:Rivers in the United States and their namesakes* James River * James River , North Dakota, South Dakota* James River * James River * James River...
. - Petersburg, VirginiaPetersburg, VirginiaPetersburg is an independent city in Virginia, United States located on the Appomattox River and south of the state capital city of Richmond. The city's population was 32,420 as of 2010, predominantly of African-American ethnicity...
on the Appomattox RiverAppomattox RiverThe Appomattox River is a tributary of the James River, approximately long, in central and eastern Virginia in the United States, named for the Appomattocs Indian tribe who lived along its lower banks in the 17th century...
. - Roanoke Rapids, North CarolinaRoanoke Rapids, North CarolinaRoanoke Rapids is a city in Halifax County, North Carolina, United States. The population was 16,957 at the 2000 census. It is the principal city of the Roanoke Rapids Micropolitan Statistical Area.-Geography:...
on the Roanoke RiverRoanoke RiverThe Roanoke River is a river in southern Virginia and northeastern North Carolina in the United States, 410 mi long. A major river of the southeastern United States, it drains a largely rural area of the coastal plain from the eastern edge of the Appalachian Mountains southeast across the Piedmont...
. - Smithfield, North CarolinaSmithfield, North CarolinaSmithfield is a town in Johnston County, North Carolina, United States. In 2008, the estimated population was 12,965. It is the county seat of Johnston County...
on the Neuse RiverNeuse RiverThe Neuse River is a river rising in the Piedmont of North Carolina and emptying into Pamlico Sound below New Bern. Its total length is approximately , making it the longest river entirely contained in North Carolina. The Trent River joins it at New Bern. Its drainage basin, measuring in area,...
. - Fayetteville, North CarolinaFayetteville, North CarolinaFayetteville is a city located in Cumberland County, North Carolina, United States. It is the county seat of Cumberland County, and is best known as the home of Fort Bragg, a U.S. Army post located northwest of the city....
on the Cape Fear RiverCape Fear RiverThe Cape Fear River is a long blackwater river in east central North Carolina in the United States. It flows into the Atlantic Ocean near Cape Fear, from which it takes its name. The overall water quality of the river is continuously measured and monitored by and conducted by the , , and the...
. - Cheraw, South CarolinaCheraw, South CarolinaCheraw is a town on the Pee Dee River in Chesterfield County, South Carolina, United States. The population was 5,524 at the 2000 census and center of an urban cluster with a total population of 9,069. It has been nicknamed "The Prettiest Town in Dixie." The harbor tub USS Cheraw was named in the...
on the Pee Dee RiverPee Dee RiverThe Pee Dee River, also known as the Great Pee Dee River, is a river in North Carolina and South Carolina. It originates in the Appalachian Mountains in North Carolina, where its upper course above the mouth of the Uwharrie River is known as the Yadkin River. It is extensively dammed for flood...
. - Camden, South CarolinaCamden, South CarolinaCamden is the fourth oldest city in the U.S. state of South Carolina and is also the county seat of Kershaw County, South Carolina, United States. The population was an estimated 7,103 in 2009...
on the Wateree RiverWateree RiverThe Wateree River, about 75 mi long, is a tributary of the Santee River in central South Carolina in the United States, which flows to the Atlantic Ocean...
. - Columbia, South CarolinaColumbia, South CarolinaColumbia is the state capital and largest city in the U.S. state of South Carolina. The population was 129,272 according to the 2010 census. Columbia is the county seat of Richland County, but a portion of the city extends into neighboring Lexington County. The city is the center of a metropolitan...
on the Congaree RiverCongaree RiverThe Congaree River is a short but wide river in South Carolina in the United States; It flows for only 47 miles . The river serves an important role as the final outlet channel for the entire Lower Saluda and Lower Broad watersheds, before merging with the Wateree River just north of Lake Marion to...
. - Augusta, GeorgiaAugusta, GeorgiaAugusta is a consolidated city in the U.S. state of Georgia, located along the Savannah River. As of the 2010 census, the Augusta–Richmond County population was 195,844 not counting the unconsolidated cities of Hephzibah and Blythe.Augusta is the principal city of the Augusta-Richmond County...
on the Savannah RiverSavannah RiverThe Savannah River is a major river in the southeastern United States, forming most of the border between the states of South Carolina and Georgia. Two tributaries of the Savannah, the Tugaloo River and the Chattooga River, form the northernmost part of the border...
. - Columbus, GeorgiaColumbus, GeorgiaColumbus is a city in and the county seat of Muscogee County, Georgia, United States, with which it is consolidated. As of the 2010 census, the city had a population of 189,885. It is the principal city of the Columbus, Georgia metropolitan area, which, in 2009, had an estimated population of 292,795...
on the Chattahoochee RiverChattahoochee RiverThe Chattahoochee River flows through or along the borders of the U.S. states of Georgia, Alabama, and Florida. It is a tributary of the Apalachicola River, a relatively short river formed by the confluence of the Chattahoochee and Flint Rivers and emptying into Apalachicola Bay in the Gulf of...
.
| State | Point (crossing) | Elevation & coordinates | Fall zone: drop/width (slope) |
Geomorphology Piedmont—Coastal plain |
|---|---|---|---|---|
| New Jersey New Jersey New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware... |
New Brunswick New Brunswick, New Jersey New Brunswick is a city in Middlesex County, New Jersey, USA. It is the county seat and the home of Rutgers University. The city is located on the Northeast Corridor rail line, southwest of Manhattan, on the southern bank of the Raritan River. At the 2010 United States Census, the population of... (Raritan River Raritan River The Raritan River is a major river of central New Jersey in the United States. Its watershed drains much of the mountainous area of the central part of the state, emptying into the Raritan Bay on the Atlantic Ocean.-Description:... ) |
460 ft (140.2 m)40°29′18"N 74°26′52"W | ||
| Trenton Trenton, New Jersey Trenton is the capital of the U.S. state of New Jersey and the county seat of Mercer County. As of the 2010 United States Census, Trenton had a population of 84,913... (Delaware River Delaware River The Delaware River is a major river on the Atlantic coast of the United States.A Dutch expedition led by Henry Hudson in 1609 first mapped the river. The river was christened the South River in the New Netherland colony that followed, in contrast to the North River, as the Hudson River was then... ) |
40°13′18"N 74°45′22"W | 8 ft | ||
| Pennsylvania Pennsylvania The Commonwealth of Pennsylvania is a U.S. state that is located in the Northeastern and Mid-Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Ontario, Canada, to the north, and New Jersey to... |
Philadelphia (Schuylkill River Schuylkill River The Schuylkill River is a river in Pennsylvania. It is a designated Pennsylvania Scenic River.The river is about long. Its watershed of about lies entirely within the state of Pennsylvania. The source of its eastern branch is in the Appalachian Mountains at Tuscarora Springs, near Tamaqua in... by I-76 Interstate 76 (east) Interstate 76 is an Interstate Highway in the United States, running 435 miles from an interchange with Interstate 71 west of Akron, Ohio, east to Interstate 295 near Camden, New Jersey.... ) |
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| Delaware Delaware Delaware is a U.S. state located on the Atlantic Coast in the Mid-Atlantic region of the United States. It is bordered to the south and west by Maryland, and to the north by Pennsylvania... |
Wilmington Wilmington, Delaware Wilmington is the largest city in the state of Delaware, United States, and is located at the confluence of the Christina River and Brandywine Creek, near where the Christina flows into the Delaware River. It is the county seat of New Castle County and one of the major cities in the Delaware Valley... (Brandywine Creek Brandywine Creek Brandywine Creek is a tributary of the Christina River in southeastern Pennsylvania and northern Delaware in the United States. The Lower Brandywine is long and is a designated Pennsylvania Scenic River with several tributary streams... ) |
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| Maryland Maryland Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east... |
Conowingo Dam Conowingo Dam The Conowingo Dam is a large hydroelectric dam in the Lower Susquehanna River. The dam, one of the largest non-federal hydroelectric dams in the US, is classified as a medium height, masonry gravity type dam... (Susquehanna Susquehanna River The Susquehanna River is a river located in the northeastern United States. At long, it is the longest river on the American east coast that drains into the Atlantic Ocean, and with its watershed it is the 16th largest river in the United States, and the longest river in the continental United... ) |
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| Ellicott City Ellicott City, Maryland Ellicott City is an unincorporated community and census-designated place in Howard County, Maryland, United States. It is part of the Baltimore-Washington Metropolitan Area. The population was 65,834 at the 2010 census. It is the county seat of Howard County... (Patapsco Patapsco River The Patapsco River is a river in central Maryland which flows into Chesapeake Bay. The river's tidal portion forms the harbor for the city of Baltimore... ) |
39°16.044′N 76°47.573′Whttp://www.hmdb.org/Marker.asp?Marker=193 | crystalline rock—unconsolidate marine sediments http://www.mde.maryland.gov/assets/document/Patapsco%20LNB%20Stressor%20ID%20Report_04-20-09.pdf | ||
| Great Falls (Potomac River) | 38°59′51"N 77°15′9"W | 76 ft/<1 mi (>1.4%) | ||
| Virginia Virginia The Commonwealth of Virginia , is a U.S. state on the Atlantic Coast of the Southern United States. Virginia is nicknamed the "Old Dominion" and sometimes the "Mother of Presidents" after the eight U.S. presidents born there... |
Fredericksburg Fredericksburg, Virginia Fredericksburg is an independent city in the Commonwealth of Virginia located south of Washington, D.C., and north of Richmond. As of the 2010 census, the city had a population of 24,286... (Rappahannock Rappahannock River The Rappahannock River is a river in eastern Virginia, in the United States, approximately in length. It traverses the entire northern part of the state, from the Blue Ridge Mountains in the west, across the Piedmont, to the Chesapeake Bay, south of the Potomac River.An important river in American... ) |
39°16.044′N 76°47.573′Whttp://www.hmdb.org/Marker.asp?Marker=193 | [west of Interstate 95 Interstate 95 Interstate 95 is the main highway on the East Coast of the United States, running parallel to the Atlantic Ocean from Maine to Florida and serving some of the most populated urban areas in the country, including Boston, Providence, New Haven, New York City, Newark, Philadelphia, Baltimore,... bridge] |
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| Emporia Emporia, Virginia Emporia is an independent city located within the confines of Greensville County, Virginia, United States. The population was estimated to be 5,927 in 2010. The Bureau of Economic Analysis combines the city of Emporia with surrounding Greensville county for statistical purposes... (Meherrin River Meherrin River The Meherrin River is a long river in the U.S. states of Virginia and North Carolina. It begins in central Virginia, about northwest of Emporia, and flows roughly east-southeast into North Carolina, where it joins the larger Chowan River.... ) |
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