12 Undergraduate Research II (Posters)

Friday, 20 March 2020
8:00 AM - 12:00 PM
Grand Ballroom A–D

GEOLOGY AND BLUE RIDGE ESCARPMENT EVOLUTION ALONG BEARCAMP, BEAR, AND BEARWALLOW CREEKS IN SOUTHWESTERN NORTH CAROLINA AND NORTHWESTERN SOUTH CAROLINA

Paper number: 12-14
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

The Blue Ridge Escarpment (BRE) is a geologic feature that has undergone a lengthy and complex evolution and one which remains controversial. The BRE stretches some 500 km along the eastern seaboard, dividing the lower elevation piedmont from the higher elevation mountainous region. This research investigates Bearcamp Creek, Bear Creek, and Bearwallow Creek in upstate South Carolina and adjacent North Carolina in order to understand how these creeks have contributed to escarpment evolution. Field studies have shown that the primary rock types along these creeks consists of Toxaway Gneiss and the Tallulah Falls Formation. Thin section analysis for the Bearcamp Creek reveals the primary mineralogy to be plagioclase (30-35%), quartz (20-25%), muscovite (20-25%), microcline (10-15%), and biotite (10%) with accessory garnet with inclusions, zircon, epidote, and magnetite. For Bearcamp Creek, softer schists of the Tallulah Falls Formation occur closer to Lake Jocassee and show signs of more abrasion in the form of deep potholes. Five joints were measured in total for the three creeks, striking generally EW with a near vertical dip. There were a total of twenty-one foliations measured for the three creeks with the majority striking NE with dominantly SE dips. Three Digital Elevation Models (DEM) were created and drainage basins were delineated from the DEMs. The drainage basin area for Bearcamp Creek is 8.59 km2 and the drainage basin area for Bear Creek is 4.88 km2. In addition, a longitudinal profile was extracted from the DEM for each creek. All of the longitudinal profiles reveal convex knickpoints and concavities between them. It was concluded that for these knickpoints the incision into the escarpment was primarily by plucking along joints whereas abrasion appears to dominate in the softer schists.

Geological Society of America Abstracts with Programs. Vol. 52, No. 2

doi: 10.1130/abs/2020SE-345247

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