INTEGRATION OF ELECTRICAL RESISTIVITY, GROUND PENETRATING RADAR, SEISMIC, GRAVITY AND MAGNETIC SURVEYS TO STUDY THE MORRISTOWN FAULT

The Morristown Fault is located in the Morristown Quadrangle in the St. Lawrence Valley in Northwestern New York. It is a northwest trending fault that crosses the Seaway Trail (Route 12) near Point Comfort, 3.5 miles south of Morristown, NY. The fault shows a displacement of several feet in the Theresa sandy dolostone, which lies upon the Potsdam sandstone and Precambrian basement. Weathering and erosion at the fault is prominent so the vertical extent and dip of the fault at depth is unknown. This integrated geophysical investigation across the fault was conducted to better understand the nature of the fault at depth.

Electrical resistivity, ground penetrating radar, seismic refraction and reflection, gravity and magnetic surveys were conducted across the fault. The gravity and magnetic surveys across the fault indicate gravity and magnetic anomalies with steep gradients located over the fault. These anomalies are due to rocks in the Precambrian basement and indicate control of the overlying Paleozoic by the Precambrian Greenville rocks.

Preliminary data from the Ground Penetrating Radar and Electrical Resistivity surveys are in agreement with the Gravity/Magnetic data. They also indicate the orientation of the fault system. The Seismic data are indicative of the fault presence but do not reveal any high-resolution features such as strike and dip of the fault planes.

There is currently no official classification of this structure. The use of multiple geophysical methods is aimed at the reduction of ambiguity within the entire data set for this fault system. The assorted techniques each display a different physical parameter of the fault and surrounding host rock. The use of multiple methods may be able to isolate some physical aspect of the fault system and provide geoscientists with more detailed information that could be used for future classification of this fault system.