Geologic Play Book for Trenton-Black River Appalachian Basin Exploration DE-FC26-03NT41856 Current state of technology used in the play. The Trenton-Black River gas play, a widespread play that encompasses an area from New York to West Virginia with additional potential in Ohio and Kentucky, is a seismic-dependent, high-technology, high-risk, deep play that has attracted national and international attention. Productive wells have been drilled in this play in New York, Pennsylvania, West Virginia and Ontario, Canada, but the nature of the play is not consistent among these various areas. In New York, production is limited to areas where hydrothermal dolomite has replaced host limestones in the Black River and lower portions of the overlying Trenton Limestone. Production in Ontario is from similar reservoirs. However, in West Virginia, production is associated with fractures and basement-deep faults that are not associated with dolomitization. The possible occurrence and extent of both types of reservoirs in Pennsylvania is not known at this time.