AIR AND WATER TEMPERATURE INVESTIGATION OF GEOTHERMAL WATER IN MUD POT CAVE, WARM SPRINGS, VIRGINIA

Falling Springs Cove is located primarily within a breached anticline located in Bath and Alleghany Counties, Virginia which features a landscape dominated by karst formed from the Middle Ordovician carbonate rock exposed at the valley floor. Despite the rarity of thermal springs in the Appalachian Mountains, Virginia is host to several, all of which are located in Appalachia from Alum Springs in the south to Bolar in the north with a concentration of thermal springs in and around Falling Springs Valley where this study took place. These hydrothermal springs are associated with water gaps on the western limbs of the anticlines and are suspected to be on faults that allow the deeply circulating water heated by the geothermal gradient to rapidly rise to the surface. As of the time of this study, there are only two known thermal caves in Virginia, both of which are in the Falling Springs Valley. These include Warm River Cave and Mud Pot Cave, both of which are located in the southern part of the valley between Falling Springs Falls and Valley View. Water emerges from the northern end of the cave, flows down gradient for 80 feet, where it disappears in an unnavigable crack at the southern end of the cave. To better understand the hydrologic and geothermal system within Mud Pot Cave, temperature loggers were installed on May 5, 2024 and were extracted on July 27, 2024. During normal flow conditions, consistent water temperatures of approximately 100 degrees Fahrenheit have been observed in the upstream pool in Mud Pot Cave, and storm events in August and September 2024 caused drops in temperature as low as 63 degrees Fahrenheit. The rapid response due to precipitation of greater than 1 inch, may indicate meteoric water is entering the system through one or more losing points in Falling Spring Creek, which only flows above Falling Spring in response to significant rainfall. Further monitoring of temperature as well as dye traces can help better understand both the source of water during high or low flows as well as the geothermal properties of the system.