2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 6
Presentation Time: 9:20 AM


PIERCE Jr, Carl J., Geology Department, St. Lawrence University, 155 Brown Hall, Canton, NY 13617, cpierce@stlawu.edu

Multiple Geophysical Studies have been conducted in a fault zone located along Route 12 approximately 3.5 miles southwest of Morristown, N.Y. This area is in the St. Lawrence Valley Region of Northern New York. Geophysical methods used at the site were; Ground Penetrating Radar (GPR), Reflection/Refraction Seismology and D.C. Resistivity.

One of the main reasons that make this fault interesting is the fact that the large main fault remains unclassified from a structural standpoint. At first glance, the fault appears to be a normal fault system when viewed from the surface. However, preliminary data taken over the fall 2006 and spring of 2007 suggests a much more complicated sub-structure. The local geology is the Theresa Dolostones of Lower Ordovician age underlain by the Cambrian age Potsdam Sandstone.

The layered carbonates in the study section are approximately 1.5m to 2.5m thick, making them detectable to GPR in the 50 MHz frequency range. They are a very massive medium that lend themselves to applications of the Reflection/Refraction seismic techniques. The carbonates are also a resistive media and can be detected using the D.C. resistivity method.

Since there is no official classification of the main fault, 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. Used together, these 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 structure.