By Sara H. Baldwin
The Williamsburg anticline is a large fold involving the Mississippian Greenbrier Group in western Greenbrier County, West Virginia. The Greenbrier Group is a series of limestones that are known for their karst development. Extensive reverse faults in these limestones have been identified recently by the author as a result of field mapping and lidar analysis. Some of these reverse faults extend as much as 18 miles and involve stratigraphic displacement of over 200 feet. Many, but certainly not all, of the major reverse faults can be traced by a distinct line of sinkholes along regional strike. This indicates that water flow is controlled by steeply dipping beds in the fault zone and/or along fractures associated with the fault surface. Caves were identified that were at or adjacent to faults. Culverson Creek and Taylor Falls Caves had entrances or passages near the faults but did not follow them. It is interesting to note that they also did not cross the faults. Piercy’s Mill Cave, Bash Cave, Zicafoose Cave, and the Bag Cave System are all strongly influenced by the faults. In these cases the caves followed steeply dipping soluble layers of limestone, but they also did not cross the faults. In conclusion, it seems likely that ground water is strongly influenced to follow along the fault zones, but does not seem to cross them readily.