GSA Annual Meeting in Phoenix, Arizona, USA - 2019

Paper No. 63-1
Presentation Time: 1:30 PM

RELIC APPALACHIAN UPLANDS ALONG THE NEW RIVER – TENNESSEE RIVER DRAINAGE DIVIDE


BARTHOLOMEW, Mervin J., Earth Sciences, University of Memphis, Memphis, TN 38152 and KWON, Youngsang, Earth Sciences, University of Memphis, 235 Johnson Hall, Memphis, TN 38152

The New River – Tennessee River drainage divide is the only divide that extends from the E-facing Blue Ridge escarpment northwestward across the Blue Ridge, fold-thrust belt, and Appalachian Plateau to the Ohio River. Broad areas of relic Appalachian Uplands occur along this divide where geologic maps, cross sections, and LiDAR are available for topographic and geomorphic analysis to assess ages relative to incision. Three areas are: 1) the Elk Knob/Long Hope Ck. area (Blue Ridge) near Boone, NC; 2) the area around Burkes Garden, VA (fold-thrust belt); and the 3) Whitesburg, KY area at the escarpment of the Pine Mtn. thrust. Elk Knob/Long Hope Ck. is a relic mountainous plateau with a low-gradient stream at 4200+ft (1282+m) that is perched above the incised North Fork of New River at 2940ft (898m). Partially riming the steep slopes are perched drainages, suggesting a 2-stage development of this relic upland. The divide trends northward to the vicinity of Burkes Garden, VA. There in the fold-thrust belt, typical structures with higher and lower synclinal benches [in Devonian strata from ~3100ft (947m) to ~2400ft (733m)] frame the relic landscape supported by resistant Silurian sandstones similar to the relic Butt Mtn./Little Ck. landscape above 3100ft (947m) west of the incised New River near Pembroke, VA at 1600ft (489m). The divide abruptly changes to a W-trend to the vicinity of Whitesburg, KY where it crosses the Pine Mtn. escarpment near Whitesburg.