Atlantic Seaboard Fall Line Explained
The Atlantic Seaboard Fall Line, or Fall Zone, is a 900miles escarpment where the Piedmont and Atlantic coastal plain meet in the eastern United States.[2] 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 alluvial plain of the upper continental shelf, formed of unconsolidated Cretaceous and Cenozoic sediments. Examples of Fall Zone features include the Potomac River's Little Falls and the rapids in Richmond, Virginia, where the James River falls across a series of rapids down to its own tidal estuary.
Before navigation improvements such as locks, the fall line was generally the head of navigation on rivers due to their rapids or waterfalls, and the necessary portage around them. Numerous cities initially formed along the fall line because of the easy river transportation to seaports, as well the availability of water power to operate mills and factories, thus bringing together river traffic and industrial labor. U.S. Route 1 and I-95 link many of the fall-line cities.
In 1808, Treasury Secretary Albert Gallatin noted the significance of the fall line as an obstacle to improved national communication and commerce between the Atlantic seaboard and the western river systems:[3]
Notable cities
Some cities that lie along the Piedmont–Coastal Plain fall line include the following (from north to south):
- New Brunswick, New Jersey on the Raritan River
- Princeton, New Jersey, on the Millstone River
- Trenton, New Jersey, on the Delaware River.[2]
- Philadelphia, Pennsylvania, on the Schuylkill River.[4]
- Wilmington, Delaware, on the Brandywine River.
- Perryville, Maryland, and Havre de Grace, Maryland, on the Susquehanna River/head of Chesapeake Bay.
- Baltimore, Maryland, on Herring Run, Jones Falls, and Gwynns Falls.[5]
- Elkridge, Maryland, on the Patapsco River.
- Laurel, Maryland, on the Patuxent River.
- Washington, D.C., on the Potomac River.[6]
- Occoquan, Virginia, on the Occoquan River.
- Fredericksburg, Virginia on the Rappahannock River.[6]
- Richmond, Virginia, on the James River.[7]
- Petersburg, Virginia, on the Appomattox River.[8]
- Weldon, North Carolina, and Roanoke Rapids, North Carolina, on the Roanoke River[9]
- Rocky Mount, North Carolina, on the Tar River.[9]
- Kinston, Smithfield, and Goldsboro, North Carolina, on the Neuse River.[9]
- Fayetteville, North Carolina, on the Cape Fear River.[9]
- Lumberton, North Carolina, on the Lumber River.[9]
- Cheraw, South Carolina, on the Pee Dee River.
- Camden, South Carolina, on the Wateree River.
- Columbia, South Carolina, on the Congaree River.[7]
- Augusta, Georgia, on the Savannah River.[10]
- Milledgeville, Georgia, on the Oconee River.[10]
- Macon, Georgia, on the Ocmulgee River.[10]
- Columbus, Georgia, on the Chattahoochee River.[2]
- Tallassee, Alabama, on the Tallapoosa River[11]
- Wetumpka, Alabama, on the Coosa River[11]
- Tuscaloosa, Alabama, on the Black Warrior River[11]
Geographic coordinates
Notes and References
- Web site: The Fall Line . A Tapestry of Time and Terrain: The Union of Two Maps - Geology and Topography . USGS.gov . 2010-08-12 . dead . https://web.archive.org/web/20110514204157/http://tapestry.usgs.gov/features/14fallline.html . 2011-05-14 . An alternate source claims the southern endpoint is farther west because there are "waterfalls & rapids":
Web site: Georgia Geology . 2010-08-13 . https://web.archive.org/web/20100904194712/http://www.gly.uga.edu/default.php?PK=0&iPage=5 . 4 September 2010 . live .
- Book: Freitag, Bob . Susan Bolton . Frank Westerlund . Julie Clark . Floodplain Management: A New Approach for a New Era . 2009 . Island Press . 978-1-59726-635-2 . 77 . 17 November 2010.
- Report on
- Book: Shamsi, Nayyar . Encyclopaedia of Political Geography . 2006 . Anmol Publications . 978-81-261-2406-0 . 92–93 . 17 November 2010.
- Web site: Maryland Geology . Maryland Geological Society . 25 January 2017.
- Book: Deane, Winegar . Highroad Guide to Chesapeake Bay . 2002 . John F. Blair . 978-0-89587-279-1 . 5 . 17 November 2010.
- Book: Roberts, David C. . W. Grant Hodsdon . Roger Tory Peterson . A Field Guide to Geology: Eastern North America . 2001 . Houghton Mifflin Harcourt . 978-0-618-16438-7 . 242 . 17 November 2010.
- Web site: Geology of the Fall Line . Virginia Places . 25 January 2017.
- Web site: Fall Line . NCpedia . 25 January 2017.
- Web site: Fall Line . The New Georgia Encyclopedia . 17 October 2011.
- Web site: Fall Line . Encyclopedia of Alabama . 25 January 2017.
- Web site: History/Culture . PatapscoHeritageGreenway.org . 2010-09-07 . George Ellicott House: A block away is the 1789 George Ellicott House at 24 Frederick Road., which has been saved, moved out of the flood plain, and restored. The Ellicott family settled here along the fall line of the Patapsco River in 1772 and built an innovative, water-powered flour mill . dead . https://web.archive.org/web/20100310084026/http://www.patapscoheritagegreenway.org/history/HistPersp.html . 2010-03-10 .
- Web site: Watershed Report for Biological Impairment of the Patapsco Lower North Branch Watershed in Anne Arundel, Baltimore, Carroll, and Howard Counties and Baltimore City, Maryland. Biological Stressor Identification Analysis. Results and Interpretation . https://web.archive.org/web/20090621075548/http://www.mde.maryland.gov/assets/document/Patapsco%20LNB%20Stressor%20ID%20Report_04-20-09.pdf . 2009-06-21 . Maryland Department of the Environment . April 2009 .
- Web site: Fall Line . VirginiaPlaces.org . 2010-08-13.
- Web site: River and "Fall Line" Cities . VirginiaPlaces.org . 2010-08-13.
