COMPLEX HYDROGEOLOGIC PATHWAYS IN CHERTY AND SANDY LIMESTONES OF THE DEVONIAN LICKING CREEK LIMESTONE AS INDICATED BY DYE-TRACING OF SINKING STREAMS ALONG CEDAR CREEK, BATH COUNTY, VIRGINIA

Dye placed in a sinking stream that enters Serpent Cave east of Cedar Creek in Bath County traveled west-southwestward beneath Hoover Ridge and Cedar Creek, and was recovered in a spring on the west bank of Cedar Creek that is the resurgence of the stream that flows in Cedar Creek Cave. Other dye traces in this vicinity likewise showed that the water in several sinking streams travels a route that takes it beneath Cedar Creek and then to a slightly higher elevation on the west bank, making Cedar Creek either a perched stream or a permanent but losing stream. The streams all sink in the Little Cove Limestone Member of the Licking Creek Limestone, immediately beneath the contact of the Licking Creek with the overlying Oriskany Sandstone. Cave exploration confirms that the streams have eroded into the underlying Cherry Run Limestone Member of the Licking Creek, which is notable for its abundant lenses, nodules, and beds of black chert. In Serpent Cave the Cherry Run contains some chert horizons that are several feet thick, leading to speculation about the importance of physical versus chemical erosion by the streams during development of the cave passages and of the subterranean passageways taken by the water beyond the known cave. We initially hypothesized that the path(s) taken by the water along its subsurface route must have been influenced by the presence of an unknown and unmapped fault or faults that presumably served as conduits for the water to travel beneath Cedar Creek and then resurge on its west bank. Detailed bedrock mapping has revealed that no faults are present, however. Instead, the most likely scenario is that the sinking streams travel downdip and to a lower elevation along a SSW-plunging syncline by following hydrologically-connected bedding planes and joints in both members of the Licking Creek. The channel of Cedar Creek coincides with the axis of this syncline in the vicinity of Cedar Creek Cave and its stream and spring, with Cedar Creek itself having cut down through the Oriskany and into the Little Cove Member, thereby forming a long but very narrow erosional window in which the upper few feet of the sandy and chert-free Little Cove Limestone Member are now exposed in the bed and streamside banks of the creek, with exposed ledges of the Oriskany Sandstone immediately above the uppermost ledges of the Little Cove Limestone Member.