RELATIONSHIPS OF GRAVITY ANOMALIES TO GAS FIELDS IN THE TUG HILL PLATEAU AND CENTRAL NEW YORK

Thirteen hundred gravity measurements were made at closely spaced intervals in areas of abandoned or inactive gas fields in the Tug Hill Plateau and Central New York. The purpose of the survey was to determine if any structural or stratigraphic trap that caused the gas accumulation could be detected by gravity mapping. The gas fields included in this study were the Pulaski, North Fulton and Sandy Creek fields in Oswego Co., the Camden field in Oneida Co. an the Baldwinville-Memphis field in Onondaga Co. The producing formation in each of these fields is the Trenton Fm. of the Ordovician Period.

The gravity map over the Camden gas field revealed a circular shape gravity high of 60 gravity units. The gas field is located on the eastern flank of this gravity anomaly. Most gravity anomalies in the area are due to rocks of varying density in the Precambrian basement however, the position of this anomaly to the field suggests a possible causable relationship.

The Pulaski an Sandy Creek gas fields lie in gravity lows and along the eastern flank of a steep gravity gradient extending northward. This steep gradient may be due to an extension of the Carthage-Colton Mylonite Zone or to possible faulting in the Trenton. The gravity lows could be due to a reduction of density in the faulted area.

The Fulton, Baldwinsville and Memphis gas fields in Oswego and Onondaga counties all lie along steep east-west trending gravity gradients associated with high gravity values. These gravity gradients indicate a change in the density of the rocks and could possibly be related to the trap causing the accumulation of gas in the areas.