COMPILATION OF STRUCTURAL FEATURES IN THE NORTHERN APPALACHIAN BASIN OF NEW YORK STATE TO ASSIST IN SITE EVALUATION AND CO2 SEQUESTRATION

Fault and fracture data are important for feasibility studies for CO₂ subsurface sequestration. For example, faults should not be present since they could allow migration of the CO₂ from the storage site. Fracture patterns and frequency also are important for CO₂ site characterization.

We have compiled over 100 layers from publications of fracture studies (e.g., Engelder and Geiser, 1980) and theses (e.g., Cruz, 2005) that display the location and orientation of faults and fractures in the central part of the northern Appalachian Basin in New York State. Additionally, we conducted limited field structure studies to verify select lineaments. The figures from previous publications were georeferenced and orthorectified in Arc GIS to create a base from which the final digitized map was constructed. Fracture spacing and frequency was calculated from the theses’ data and imported into Arc to create point layers. Once completed the point layers were queried by the fracture frequency of each orientation and a layer was created for fracture frequencies of < 2 fractures/m, 2 to 4 fractures/m and >4 fractures /m for each fracture set orientation. A similar operation was completed for the field structural data we collected. Rose diagrams were also constructed for our field data that show fracture frequency and abutting relationships.

We utilized these data sets to test the credibility of the lineaments identified from satellite images and DEMs in Zelazny et al. (2010). We used the weights of evidence statistical technique to gauge the degree of spatial correspondence between the structural data sets and the lineaments. We found that northerly- and westerly trending lineaments appear to be underrepresented compared to the number of similarly-oriented fractures in the region. The observed lineament pattern does reflect other fracture sets, and many of the know fault systems are represented in the lineament data.