Presenter
Peter D. Warwick, Ph.D.
Project Chief of the Utilization of Carbon and other Energy Gases
Geologic Research and Assessments Project
U.S. Geological Survey, Reston VA
Description
The primary coal-bearing strata of the U.S. Gulf of Mexico Coastal Plain occur in Upper Cretaceous, Paleocene, and Eocene coastal, deltaic, and fluvial sediments deposited along the north-northwestern margin of the Gulf of Mexico Basin. Coal ranks in this area range from lignite to bituminous. Most of the coal currently mined in Texas is lignite from the upper part of the Wilcox Group (Paleocene to Eocene), whereas in Louisiana and Mississippi, lignite is mined from the lower part of the Wilcox Group. Other Gulf of Mexico Coastal Plain coal-mining areas in south Texas and northern Mexico have produced bituminous coal from the Upper Cretaceous Olmos Formation and Eocene Claiborne Group, and lignite from the Eocene Jackson Group. Coal beds within the Gulf of Mexico Coastal Plain generally are less than 15 ft thick and most coal mines produce from several beds. All coal-bearing strata dip regionally into the Gulf of Mexico Basin unless disturbed by local faulting or folding.
The U.S. Geological Survey (USGS) has assessed recoverable coal and coalbed gas resources of the Gulf of Mexico Coastal Plain. Detailed assessments of coal quality and coal resources were focused on parts of the Wilcox Group in (1) northeast Texas, (2) central Texas, and the Sabine uplift in (3) Louisiana and (4) Texas. Estimates of coal in these areas total 97 billion short tons with less than 500 ft of overburden, or 175 billion short tons with less than 2000 ft of overburden (Warwick and others 2011, American Association of Petroleum Geologists Studies in Geology No. 62). The USGS assessment of coalbed gas resources of the Gulf of Mexico Coastal Plain estimated a mean of 4.06 trillion cubic feet of undiscovered, technically recoverable, continuous gas resources primarily from the Wilcox Group coals (Warwick and others 2007, https://pubs.usgs.gov/fs/2007/3039/).
