Summary

Description

The Apparent Wilcox Group thickness maps are contoured from location and top information derived from the Petroleum Information (PI) Wells database. The Wilcox apparent thickness map was constructed by searching for Wilcox and Midway Group tops. Apparent thickness is computed by subtracting Midway top from the Wilcox top. Geographic control is superimposed on the maps from USGS state line, county, elevation and other data files. The veracity of the PI Wells database is being checked by comparison to published cross sections and geologic maps. Interpretation of the depth to Wilcox and apparent thickness maps along with published measured sections and cross sections indicates that portions of Texas, Louisiana, Mississippi and Alabama contain broad areas where a 20 to 40 foot net thickness of lignite and coal occur at shallow depths. The thicker coal zones are attributed to growth faulting or rift zones influencing peat deposition. The depth to Wilcox map shows several areas where dome-like uplifts and bench-like coal-bearing rock are buried to depths less than 5,000 ft.