FRACTURES IN THE COLLINS CENTER 7.5' QUADRANGLE, WESTERN NEW YORK STATE: IMPLICATIONS FOR FAULTING

The Collins Center 7.5' Quadrangle is located in western New York State (NYS) and lies along the proposed northeastern section of the northeast-striking Bass Island Trend (BIT). Bedrock fracture characteristics were measured for over 2000 fractures at 356 outcrops. Fracture characteristics include orientation, dip, spacing, fracture abutting relationships, and fracture geometry. Fracture data were separated into sets based on orientation and master/abutting relationship. We identified Fracture Intensification Domains (FIDs) in outcrop based on fracture orientation, frequency, and abutting relationships. FIDs elsewhere in NYS indicate a high probability of faulting.

Fractures coincident with short-length topographic lineaments indicate structural control of streams. Long lineaments (> ~1 km) are colinear with fracture sets that have a high fracture frequency; these integrated data may indicate locations of faults. In the eastern and western part of the map area, long N-striking topographic lineaments are coincident with N-striking FIDs. A series of at least four NW-striking FIDs are colinear with long NW-striking topographic lineaments. Soil gas anomalies (Nelson, 2001) confirm the NW-striking shallow faults. NE-striking FIDs are present in the northeastern part of the map area where the lineaments are less developed than the NW-striking and NS-striking lineaments. The NE and NW-striking FIDs/lineaments may indicate shallow Alleghanian thrust ramps and lateral ramps associated with the BIT. Deeper structures may also follow these trends. E-W lineaments and fractures also occur in a few localities. The E-W and N-striking FIDs/lineaments may indicate deeper faults that probably affect the Trenton/Black River section.