MAPPING THE REGIONAL ORGANIC THICKNESS OF THE “MARCELLUS SHALE,” HAMILTON GROUP

Regional and statewide isopach maps have been developed for the Middle Devonian Marcellus Shale for use in assessing Ohio’s shale gas potential. Existing stratigraphic analyses of Devonian shales in Ohio were used as the starting dataset, which was expanded with additional geophysical logs that span the Marcellus Shale in each county and township, where available; this approach allowed for an even distribution of control points and more consistent correlations. This correlation expansion of the Hamilton Group, Marcellus Shale, and Onondaga Limestone was based on U.S. Geological Survey cross sections published in Bulletin 1909. Using this newly compiled data and observing the Marcellus Shale’s upper and lower units, net organic thickness was calculated and contoured. Additional data was also collected from the state geological surveys of New York, Pennsylvania, and West Virginia to create a new regional map of organic thickness of the Marcellus Shale.