Subsurface Devonian and Mississippian Gas Shale Samples Barnett and Smithwick Shales (Fort Worth Basin) and Woodford and Barnett Shales (Delaware Basin) Core Sampling for Measured Vitrinite Reflectance Determination

This report summarizes activities carried out by the Bureau of Economic Geology (BEG) during Fiscal Year (FY) 2007 for the National Coal Resources Data System State Cooperative Program (NCRDS project). The report represents a departure from those prepared in previous years by providing a collection of Devonian-Mississippian and Mississippian gas-shale samples. Approval for this change in sample type was given by the USGS in March 2008. Samples were collected from whole cores of three wells in Wise and San Saba Counties, Fort Worth Basin, North Texas (Fig. 1), and Pecos County, Delaware Basin, West Texas (Fig. 2) for vitrinite-reflectance (Ro) analysis by the USGS. Other study activities include identification of the sampled shales' precise geographic location and their stratigraphic position.