Huminite Reflectance Measurements of Paleocene and Upper Cretaceous Coals from Borehole Cuttings, Zavala and Dimmit Counties, South Texas

The reflectance of huminite in 19 cuttings samples was determined in support of
ongoing investigations into the coal bed methane potential of subsurface
Paleocene and Upper Cretaceous coals of South Texas. Coal cuttings were
obtained from the Core Research Center of the Bureau of Economic Geology, The
University of Texas at Austin. Geophysical logs, mud-gas logs, driller's logs,
completion cards, and scout tickets were used to select potentially
coal-bearing sample suites and to identify specific sample depths. Reflectance
measurements indicate coals of subbituminous rank are present in a wider area
in South Texas than previously recognized.

[Summary provided by the USGS.]