| 翻訳と辞書 |
| Atlantic Seaboard fall line ： ウィキペディア英語版 |
Atlantic Seaboard fall line
The Atlantic Seaboard Fall Line, or Fall Zone, is a 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 Cenozoic sediments. 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 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. The Great Falls of the Potomac River is one example. Because of the commercial traffic, required labor and availability of water power to operate mills, numerous cities were founded at the intersection of rivers and the fall line. U.S. Route 1 links 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:〔(on ) Roads and Canals, Communicated to the Senate April 4, 1808, (p.729 )〕
==Notable cities==
Some cities that lie along the Piedmont—Coastal Plain fall line include the following (from north to south):
* Paterson, New Jersey on the Passaic River
* Trenton, New Jersey on the Delaware River.〔
* Philadelphia, Pennsylvania on the Schuylkill River.
* Wilmington, Delaware on Brandywine Creek.〔
* Newark, Delaware on the Christina River.
* Stanton, Delaware on the White Clay Creek.
* Elkton, Maryland on the Elk 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.
* Elkridge, Maryland on the Patapsco River.
* Laurel, Maryland on the Patuxent River.
* Washington, D.C. on the Potomac River.
* Occoquan, Virginia on the Occoquan River.
* Fredericksburg, Virginia on the Rappahannock River.〔
* Richmond, Virginia on the James River.
* Petersburg, Virginia on the Appomattox River.
* Roanoke Rapids, North Carolina on the Roanoke River.
* Raleigh, North Carolina on the Neuse River.
* Greenville, North Carolina on the Tar River.
* Fayetteville, North Carolina on the Cape Fear River.
* Cheraw, South Carolina on the Pee Dee River.
* Camden, South Carolina on the Wateree River.
* Columbia, South Carolina on the Congaree River.〔
* Augusta, Georgia on the Savannah River.
* Milledgeville, Georgia on the Oconee River.
* Macon, Georgia on the Ocmulgee River.
* Columbus, Georgia on the Chattahoochee River.〔
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
■ウィキペディアで「Atlantic Seaboard fall line」の詳細全文を読む
スポンサード リンク
| 翻訳と辞書 : 翻訳のためのインターネットリソース |
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.
|
|