GRAVITY AND MAGNETIC INVESTIGATIONS OF THE CLARENDON-LINDEN FAULT

The Clarendon-Linden structure is the most prominent structural feature in the Paleozoic rocks of western New York. It was discovered by Chadwick (1920) when he suggested the existence of a large fault between the towns of Clarendon and Linden, NY. He found a displacement of the Onondaga and Niagara escarpments with the western side farther north and at a lower elevation than those on the east. This led Chadwick to believe the structure is a fault with the downthrown side on the west.

The Clarendon-Linden fault is located on the western flank of a gravity and magnetic anomalies that traverse western New York. These anomalies are due to density and magnetic susceptibility contracts in the Precambrian basement. It seems likely that the Clarendon-Linden fault in the Paleozoic rocks reflect a Precambrian basement structure that controls the fault. Near Attica, NY where a major earthquake occurred the gravity high diverges to the northwest into an area of moderate seismicity.

Upward and downward continuation and second vertical derivative filtering were conducted on the gravity data along the fault to create filtered gravity maps. Upward continuation to heights of 3.2, 6.4 and 9.6 km indicate the sources of the anomalies extend to at least 9.6 km. The downward continuation gave a sharper anomaly separation to reveal sources at shallow depths. The second vertical derivative map shows a series of gravity maxima of shallow origin that trend along the fault.