GSA Annual Meeting in Indianapolis, Indiana, USA - 2018

Paper No. 108-3
Presentation Time: 9:00 AM-6:30 PM

VERIFICATION OF AND EXPANSION UPON THE USE OF CAVE SCALLOPS IN RECREATING HYDROGEOLOGIC CONDITIONS IN KARST AQUIFERS


HALL, Andrew, Geological Sciences, Ohio University, 139 University Terrace, 316 Clippinger Laboratories, Athens, OH 45701 and SPRINGER, Gregory S., Geological Sciences, Ohio University, Athens, OH 45701

Turbulent flow across soluble bedrock can form concave dissolution features known as scallops. Scallops have been used to recreate paleoflow conditions in cave conduits by deriving floodwater velocities and discharge from scallop lengths. The continuity equation has been used to test the reproducibility of derived discharges from scallop lengths. We attempt to verify and extend the application of scallops in recreating paleoflow conditions in karst aquifers. We have measured scallops and performed Wolman pebble counts in five caves in Greenbrier County, West Virginia, and are performing statistical analyses on the measurements. We are using the scallop data to test for the constancy of flow rates throughout a given passage (continuity), uniform vs. non-uniform flow, the effect on scallop lengths due to vertical position in a cave passage, the effect of comparatively large scallop lengths (outliers) on the derived discharge values and finally correlations between sediment/pebble size and scallop-derived shear stresses in passages. Each of these hypotheses is being rigorously analyzed by comparing statistical distributions, means, and variances. The understanding of the complex nature of cave systems and karst aquifers will be significantly expanded by improving the usage and reliability of scallops. We will present the results of the above tests and place them in the context of previous studies.