Correlation of the Wilcox Producing Zones (Late Paleocene- Early Eocene) of Southwestern Mississippi with the Type Midway/Wilcox Section of Alabama

D. T. Dockery, III
Mississippi Office of Geology, Jackson, MS

Regional cross sections were constructed in the Paleocene-Eocene section of southern Mississippi to aid in the state’s ongoing surfacegeology mapping effort. These included a north-south section along _88^o46' W longitude, east-west sections along the 31^st parallel from Alabama to the Mississippi River, and a north-south section along the Mississippi Embayment axis. This work allowed the following correlations to be made between the Wilcox producing zones of southwestern Mississippi and the Alabama type section: (1) the basal “Wilcox” sands, containing delta-sand lobes A & B, are equivalent to the Oak Hill Member (Naheola Formation, Midway Group), (2) the Minter Sand, generally the base of Wilcox production, is equivalent to the middle part of the Ostrea thirsae Bed (Nanafalia Formation, Wilcox Group), (3) the sometimes limy McKittrick Sand is equivalent to the Salt Mountain Limestone (top of the Ostrea thirsae bed), (4) the Big Shale and Baker Shale correlate respectively with the bottom and top of the Grampian Hills Member (Nanafalia Formation), (4) resistivity spikes on some geophysical logs spaced at oneand two-thirds intervals above the base of the Tuscahoma Formation may be the Greggs Landing and Bells Landing members, respectively, and (5) regressive-shale units above the concretionary, transgressivemarine sands of the Bashi Formation (basal Eocene) and the 4,600' Sand mark the base and the top of the Hatchetigbee Formation (uppermost Wilcox Group).

AAPG Search and Discovery Article #90901©2001 GCAGS, Annual Meeting, Shreveport, Louisiana