A fall line (or fall zone) is a geomorphologic unconformity (e.g., monoclinal faulting or flexing) 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. Many times a fall line will recede upstream as the river cuts out the uphill dense material, often forming “c”-shaped waterfalls. Because of these features riverboats typically cannot travel any farther inland without portaging, unless locks are built there. On the other hand, the rapid change in elevation of the water, and the resulting energy release, makes 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.
Read more about Fall Line: United States, Canada
Famous quotes containing the words fall and/or line:
“Mrs. Zajac knows you didn’t try. You don’t just hand in junk to Mrs. Zajac. She’s been teaching an awful lot of years. She didn’t fall off the turnip cart yesterday. She told you she was an old-lady teacher.”
—Christine Zajac, U.S. fifth-grade teacher. As quoted in Among Schoolchildren, “September” section, part 1, by Tracy Kidder (1989)
“I had crossed de line of which I had so long been dreaming. I was free; but dere was no one to welcome me to de land of freedom. I was a stranger in a strange land, and my home after all was down in de old cabin quarter, wid de ole folks, and my brudders and sisters. But to dis solemn resolution I came; I was free, and dey should be free also; I would make a home for dem in de North, and de Lord helping me, I would bring dem all dere.”
—Harriet Tubman (c. 1820–1913)