SIMPLE BOUGUER GRAVITY MAPS OF NEW YORK STATE

About 16,000 gravity stations have been established in New York State and eastern Pennsylvania to construct a gravity map of New York and larger scale maps of northern, western, and southeastern New York and the Tug Hill Plateau.

The gravity map of northern New York reveals a series of gravity highs extending northwestward across the northern Adirondacks. The source of these anomalies is probably a series of mafic plutons of high density. Earthquake epicenters are clustered along these gravity highs. South of these gravity highs is a gravity low over the anorthosite massif. In the Champlain Valley, a northeast trending fault lies along a gravity high and north of Plattsburgh is a circular shaped gravity high.

The gravity maps of western New York shows a series of gravity highs extending northward into Lake Ontario. These gravity highs lie along the Clarendon-Linden fault and branch northwestward near Attica, NY. A belt of earthquakes extends along the northwest branch and may be related to the gravity highs. The north trending gravity anomalies extend across Lake Ontario as revealed by gravity surveying in the lake. The correlation of the gravity anomalies with the Clarendon-Linden fault indicates that possibly the fault extends across the lake. The major gravity feature on the southeastern map is an elliptically shaped gravity high extending 240 miles from Albany, NY to Harrisburg, PA. This anomaly may be due to a dense mass deep within or at the base of the crust.