COAL RESOURCES IN THE U.S. GULF OF MEXICO COASTAL PLAIN

The U.S. Geological Survey has conducted an assessment of the Nation’s coal deposits that potentially could be mined during the next 30 or more years. For the Gulf of Mexico Coastal Plain (GMCP), the report includes reviews of the stratigraphy, coal quality and resources, and coalbed methane (CBM) potential of the Cretaceous, Paleocene, and Eocene lignite to bituminous coal deposits of the region.

Detailed resource assessments were conducted on four areas containing Paleocene-aged lignite-bearing strata of the Wilcox Group that produce most of the approximately 60 million short tons (mst) of coal mined annually from Texas and Louisiana. Two assessment areas are within the Sabine Uplift of Louisiana and Texas. The other two areas are in Northeast Texas and Central Texas. The four areas are partially contiguous but reflect geologic differences that impact both coal thickness and quality. Estimated coal resources, rounded to two significant figures, that have less than 500 ft of overburden for the four assessed areas, are as follows: Louisiana Sabine, 1,400 mst; Texas Sabine, 72,000 mst; Northeast Texas 16,000 mst, and Central Texas 7,700 mst. Within these assessment areas, an estimated 11,000 mst of coal resources lie beneath Federally managed and private land within the boundaries of Federally designated areas.

The new coal resource estimates for the GMCP indicate that previous resource estimates were low. Unlike previous coal assessments of the area, the current USGS team assessed resources zone-by-zone because the team had access to proprietary data that were not previously available. Ongoing research indicates that coal zones in both the upper and lower Wilcox Group may be more laterally extensive than previous studies indicated. Although lignite resources are abundant in the GMCP, coal quality issues, e.g. low calorific value, high moisture content, and non-compliant coal, may limit large-scale development of these resources in the near future. Deep basin CBM resources, however, may be significant in the region and suitable for development. The digital maps, resource and coal quality databases, and interpretive reports compiled for the GMCP will be released in a CD-ROM format.