Southeastern Section - 68th Annual Meeting - 2019

Paper No. 47-3
Presentation Time: 2:40 PM


BARTHOLOMEW, Mervin J.1, KWON, Youngsang2, STEWART, Kevin G.3, HILL, Jesse S.4, WOOTEN, Richard M.5, WITT, Anne C.6, PRINCE, Philip6, EVANS, Mark A.7, JACKSON Jr., William T.8 and COOK, Brian9, (1)Earth Sciences, University of Memphis, Memphis, TN 38152, (2)Earth Sciences, University of Memphis, 235 Johnson Hall, Memphis, TN 38152, (3)Department of Geological Sciences, UNC Chapel Hill, Chapel Hill, NC 27599; Department of Geological Sciences, UNC Chapel Hill, Chapel Hill, NC 27599, (4)Department of Geological Sciences, UNC Chapel Hill, Chapel Hill, NC 27599, (5)North Carolina Geological Survey, 2090 US Hwy 70, Swannanoa, NC 28778, (6)Division of Geology and Mineral Resources, Virginia Department of Mines, Minerals, and Energy, 900 Natural Resources Drive, Suite 500, Charlottesville, VA 22903, (7)Department of Geological Sciences, Central Connecticut State University, 1615 Stanley Street, New Britain, CT 06050, (8)Department of Earth Sciences, University of South Alabama, Mobile, AL 36608, (9)Geological Survey of Alabama, P.O. Box 869999 Tuscaloosa, AL 35486

Relic Appalachian Uplands mostly occur in three locations: 1) stretches of Eastern Continental Divide where drainage-divides separate major river systems along/east of Mississippi River (Tennessee-Cumberland; Kanawha-New River; Ohio-Alleghany-Monongahela) from Atlantic coastal river systems (e.g., Delaware; Susquehanna; Potomac; James; Roanoke; Pee Dee; Savannah) and Gulf of Mexico (Chattahoochee); 2) stretches of drainage-divides of major Atlantic coastal river systems (e.g., in Blue Ridge along James/Potomac systems); and 3) stretches of upper Mississippi systems drainage-divides (e.g., upper New River/upper Tennessee systems). Only along the oldest relic parts of these divides do elevated, low-gradient drainages exist in the Appalachian region above escarpments dominated by erosion of competing mass-wasting processes. Examples of these oldest landscapes (referred to by relic streams/nearby peaks) are: Long Hope Ck.-Elk Knob, NC; upper Little Stony Ck.-Butt Mtn., VA; Stony Ck.-Devils Knob, VA; Chimney Rock, NC. Some (like Long Hope Ck.-Elk Knob, west/above an asymmetric ~200-300m-high E-facing escarpment incised by upper New River, NC) indicate retreat of ancient escarpments. Others reflect Appalachian structural landscapes (upper Little Stony Ck.-Butt Mtn., VA; Lookout Point, GA). Some with multiple periods of incision, possibly reflect uplift (Stony Ck.-Devils Knob, VA; Chimney Rock, NC). Residual, lithological-controlled components dominate other areas (Cumberland Plateau, TN; Blue Knob region, PA). Once competing mass-wasting processes along a divide capture relic upland streams, then that divide is non-reversibly lowered as a diminishing linear ridge. Larger relic uplands with streams are preferentially preserved due to lithology/structural setting.