INVESTIGATION OF THE UNDER EXPLORED CAMBRIAN AND ORDOVICIAN OF SOUTHWESTERN CHAUTAUQUA COUNTY, NEW YORK

A six-quadrangle area of southwestern Chautauqua County, New York was studied, as part of a NYSERDA project, to examine the potential for Trenton-Black River reservoirs. This area is heavily drilled to the Bass Island Formation and Medina/Whirlpool Formations. However, it is under explored for deeper reservoirs in the Cambrian-Ordovician. The study site was also chosen because it was outside the current area of exploration focus farther to the east in Steuben and Chemung Counties.

The Trenton/Black River exploration currently active in the Finger Lakes region of New York appears to be associated with a series of east-west trending graben features. In Ohio, the Trenton-Black River play in Ashtabula County appears to be associated with a cross strike discontinuity. In both areas, the features are basement structural features and can be imaged, to differing degrees, with aeromagnetics. Their effects due to reactivation can also be mapped in the sedimentary cover. Given the proximity of both areas to Chautauqua County, either structural style could be evident.

Billman Geologic Consultants and Centennial Geoscience completed a computer-based mapping of the available shallow data attempting to define expression of deeper structures in the sedimentary section. Structure and isopach maps were prepared for a number of laterally continuous horizons. A new aeromagnetic survey was also flown to correlate with the geologic data. A cross-strike feature, identified by both the geologic mapping and aeromagnetic data, has similar characteristics to Saybrook Field in Ashtabula County, Ohio. Also, both data sets display examples of linear structural highs. Similar structural highs have produced nearby from the Cambrian Beekmantown Formation.

The geologic mapping and the aeromagnetic interpretation were compiled to form a structural model for southwest Chautauqua County, New York’s Cambrian-Ordovician reservoirs. Prospect leads have been delineated and will be discussed.