TRACING DEEP STRUCTURE: FRACTURE ANALYSIS IN THE FINGER LAKES REGION OF THE APPALACHIAN PLATEAU, NEW YORK STATE

The hydrothermally altered carbonates of the Trenton-Black River section are currently the most prolific natural gas play in the Appalachian Plateau of New York State. The target of this play is sag-style structures, which are associated with structures in the Precambrian basement. Our research conducted along the southeastern shore of Seneca Lake demonstrates that the trends of deep faults observed in proprietary seismic and regional aeromagnetic data can be recognized at the surface through an integration of fracture intensification domains (FIDs), soil gas anomalies and EarthSat (1997) lineaments.

The collected fracture data include nine characteristics for over 2550 fractures in the Devonian Catskill Delta sediments. The fractures were grouped into sets for which fracture frequency was determined. Spatial variations in fracture frequency are displayed through the use of modified rose diagrams and transects that run perpendicular to each set.

Based on variations in fracture characteristics, the study area can be divided into two portions. While northerly striking FIDs are common in both potions, easterly striking FIDs become common north of Hector, New York. ENE-striking FIDs are prevalent north of Valois, and are coincident with ENE-trending Landsat and aeromagnetic lineaments as well as soil gas anomalies. These ENE-striking lineaments and FIDs are localized in regions where seismic reflection profiles display Trenton/Black River sags. Spatial coincidence, along with relative timing for the sets inferred from interactive geometries, suggests that reactivation of the Trenton-Black River faults guided fracture development in the Devonian section.