An open flow of 3,500,000 cubic feet of natural gas per day in the upper part of the Tully limestone in a well northwest of Richburg in Allegany County, New York, in September, 1928, started an active drilling campaign which has extended over a large part of west-central New York and adjacent parts of north-central Pennsylvania. This led to the discovery of the Wayne-Tyrone gas pool in Schuyler County, New York, in March, 1930; the Tioga pool in Tioga County, Pennsylvania, in September, 1930; and the Hebron pool in Potter County, Pennsylvania, in November, 1931. In these three pools the gas occurs in the Oriskany sandstone.
From a great many of the wells complete sets of drill cutting samples have been taken, so that accurate sections of the strata penetrated can be constructed. Through the courtesy of companies and individual operators engaged in drilling in this area, samples from . . .