GSA Connects 2023 Meeting in Pittsburgh, Pennsylvania

Paper No. 178-4
Presentation Time: 8:00 AM-5:30 PM

CONTROLS ON THE FORMATION OF EROSIONAL BEDFORMS: SCALLOPS


OLESON, Ethan and COVINGTON, Matthew, Department of Geosciences, University of Arkansas, 216 Gearhart Hall, Fayetteville, AR 72701

Scallops are cup-like, asymmetrical, features in large fields found in caves around the world. Scallops are thought to form by variations in dissolution rate produced by turbulent flow structures. While scallops are common, models of speleogenesis under turbulent conditions predict dissolution is controlled by bulk water chemistry and that features that form from flow structures should not exist. This apparent conundrum opens questions about our understanding of scallop formation, speleogenetic models, or both. In this study, we explore potential controls such as lithology and grain size, and whether mechanical processes may develop scallops. This study uses common methods, such as petrography, Wolman pebble counts, and SEM, as well as novel ones, such as photogrammetry and micro-surface roughness. Data collection will require both fieldwork and literature review of cave and surface sites in multiple lithologies, hydrologic conditions, and climate zones. This study on the controls of scallops will contribute to the fields of fluvial geomorphology and speleology by helping us better understand erosion in soluble bedrock channels.