CARBONATE WEATHERING IN THE MAURY RIVER WATERSHED IN ROCKBRIDGE COUNTY, VIRGINIA

Dissolution of carbonate minerals plays a significant role in the global carbon cycle. A better understanding of watershed-scale weathering processes can be reached by studying factors controlling CO₂ consumption through soil and groundwater analysis. The study area is located within the Maury River Watershed in Rockbridge County, VA. The valley is underlain by Cambo-Ordivician carbonates of variable compositions. Within the watershed, three monitoring sites have been installed including one on the Lincolnshire formation, a high calcium limestone with 95% CaCO₃, the Edinburg formation, an impure limestone with more than 20% non-carbonate components, and on the Beekmantown formation, a high Mg dolomite with at least 30% magnesium carbonate. The site setup includes lysimeters at four different depths to bedrock (to sample soil water for pH, alkalinity, Ca²⁺, and Mg²⁺), CO₂ monitors, temperature probes, moisture blocks, and rain gauges. In addition, local spring geochemistry is being monitored. The goal of the study is to determine the relationships between rock type, climatic factors, and weathering and to estimate the consumption of CO₂ during weathering within the watershed.