Jacobi, Robert D.1, Gerald Smith1, John Fountain1,
Fagan2, Industrial Associates1
(1) University at Buffalo, Buffalo, NY
(2) Centennial Geoscience, Amherst,
ABSTRACT: Fault Systems in New York State and Carbonate Reserviors: Trenton/Black River and Younger Plays
Dissolution by hydrothermal fluids migrating along fractures resulted in the dolomitization and vuggy porosity characteristic of carbonate reservoirs of the Trenton/Black River (TBR) play in the Appalachian Basin of central New York State (NYS). Seismic lines in central NYS show that the controlling faults involve Precambrian basement. On seismic, narrow grabens with increasing offset upsection through the Trenton/Black River mark many of the fields.
Do similar faults exist outside the central NYS plays? In western NYS seismic lines indicate that faults in the Precambrian basement also extend through the TBR. Examples include the N-striking Clarendon-Linden Fault System (CLF) and the N-striking West Valley Fault System (located west of the CLF). Seismic and well logs indicate that these and other N-striking faults were extensional (normal) faults in early Taconic times, consistent with tectonic models that indicate Taconic E-W Laurentian plate extension related to plate flexure over the peripheral bulge (and into the trench). The N-striking faults thus were "open", and probably promoted fluid migration (as did the ~ N-striking faults in the Mohawk Valley). N-trending seismic lines in western NYS display fewer TBR features, but NW-striking cross-strike discontinuities (CSDs) affect the TBR. Most of the fault trends were established by integrating Landsat lineaments with topographic lineaments, geopotential field gradients, fracture intensification domains, and soil gas anomalies. In northwestern NYS, veins in the Silurian Lockport indicate additional fluid circulation and dolomitization in Silurian times, primarily along ENE-trends. East of the Finger Lakes, recently reprocessed seismic also indicates faults that affected the TBR.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.