The present Blue Ridge scarp seems to have been produced by a late Tertiary normal fault—the Blue Ridge border fault. Evidence of its existence can be found along an almost straight line extending about 700 miles from the vicinity of Gainesville, Georgia, to northwestern New Jersey.

Throughout much of its length, the Blue Ridge border fault seems to have utilized pre-existing structures of an older Triassic fault zone which borders the Blue Ridge scarp on the east.

The Asheville peneplain of the upthrown fault block is considered correlative with the Piedmont peneplain on the downthrown block. Both are probably correlative with the Schooley peneplain. The Asheville surface descends gradually via the Dahlonega Plateau from elevations approximating 2100 feet on the strath of the French Broad River near Brevard, North Carolina, to coalescence with the Piedmont surface southwest of Hightower, Georgia, at elevations approximating 1200 feet.

The higher mountains of the Blue Ridge Upland are pre-fault features, and such outlying ranges as the Brushy and South mountains of the upper Piedmont of North Carolina are their equivalents on the downfaulted block.

The higher mountains of the Southern Appalachians are on the upfaulted block in the region of greatest uplift. The southwestern extension of the Southern Appalachians beyond the end of the fault was not uplifted.

First Page Preview

First page PDF preview
You do not currently have access to this article.