GRAVITY AND MAGNETIC INVESTIGATIONS IN SOUTH CENTRAL NEW YORK AND STEUBEN COUNTY

Two gravity anomalies are of interest in Steuben County, NY. A gravity high 12 miles south of Corning, NY in Steuben County and a gravity low in the middle of Steuben County. The gravity high extends across the New York border into Tioga Co., Pennsylvania, where it was first mapped by Howell and Vozoff (1953), and later by Revetta (1967). This anomaly is circular in shape with gravity values ranging from -30 to -44 mGals. It covers an area of 900 square miles and has a magnitude of 14 mGals. Howell and Vozoff believe the anomaly is due to an intrusion of diabase.

In the center of Steuben County northwest of Corning, NY is a gravity low. This simple Bouguer anomaly reaches a low of -58 mGal. The magnitude of the anomaly is 12 mGals and a gradient of 1.5 mGals/km. The anomaly is located in an area where the basement is buried beneath 3,500 meters of overlying Paleozoic sediment. The Marcellus Shale, a Middle Devonian black low-density shale extends into this area. Its low density would produce a gravel low as shown in central Steuben Co.

The magnetic map (J. Wallach) covers the area southwest of Lake Ontario between 42° 15' and 43° 30' north latitude and 75° and 77° west longitude. The magnetic anomalies originate in the PreCambrian basement. These anomalies are due to variations in the magnetic susceptibility or basement topography. The magnetic highs could indicate shallow basement or the upwarp of the overlying sedimentary rock. These upwarped areas may serve as oil or gas traps in the area.