INTEGRATION OF FRACTURE PATTERNS AND LINEAMENTS FOR FAULT MAPPING IN THE APPALACHIAN BASIN OF CENTRAL NEW YORK STATE

This study integrates surface structure data with lineaments in order to map possible fault patterns in southwestern Chenango County, New York. Bedrock studied in the region are outcrops of the Middle to Upper Devonian Catskill Delta Complex. The only previous study in the region was by Pyron et al. (2003) who correlated lineaments from an aerial photo mosaic to soil gas and paleomorphic data to determine possible structure trends in fractured shale wells of the sites in the Genegentslet field. The current research is the first structural groundtruthing of lineaments in the region.

Characteristics of approximately 2500 surface bedrock fractures were collected within the study area, following standard UB Rock Fracture Group protocols. These include strike, dip, spacing between fractures in the set, height and length of the fractures at the surface, type of bedding, bedding thickness in which the fractures occur, the abutting relationships among fractures, fracture surface decorations and fracture linearity. Fracture characteristics are displayed using modified rose diagrams which show fracture orientation, frequency, and fracture abutting relationships. Three regional fracture orientations are common to this region: a north–northeast-striking joint set, an east-striking set and a N60° E-striking set. Fracture Intensification Domains (FIDs) are also common in the region and are characterized by closely spaced fractures. In other study areas FIDs have been found to indicate faulting.

Bedrock fracture data are combined with lineaments which were identified from satellite imagery, gravity anomalies and aeromagnetic gradients. A single zone of widely-spaced Earthsat (1997) lineaments trends north-south and is coincident with an aeromagnetic anomaly, and with sites that display north-striking fracture cleavage. A north–northeast-trending lineament zone also is coincident with sites where we observed north-northeast- striking FIDs; this lineament is sub-parallel to the assumed Rome Trough gravity low. Other lineament zones which run north-northwest and east-west are not coincident with gravity or magnetic data; these lineaments are thus probably of shallow origin. We have no bedrock sites where these lineaments occur.