TEXTURAL AND PETROGRAPHIC ANALYSES OF SANDSTONES FROM THE UPPER CRETACEOUS TUSCALOOSA GROUP IN THE SOUTH-CENTRAL MISSISSIPPI EMBAYMENT

This ongoing study is conducted on the Tuscaloosa Group in the south-central part of the Mississippi Embayment. This study aims to investigate the petrography of Tuscaloosa sandstones, which can provide significant insights into the digenesis of the Tuscaloosa. The Tuscaloosa Group is known to contain productive oil reservoirs as well as productive aquifers; hence, characterizing Tuscaloosa sandstones can help to evaluate the qualities of economic strata over a regional scale. Cores from five wells located in southwestern Alabama and samples collected from several outcrops in west-central Alabama and northeastern Mississippi are used in this study. Basic rock properties were described and recorded, including average grain size, grain shape, and sorting. Thin sections will be made from ~ 50 samples selected from cores and outcrops. Thin-section microscopy will be performed to document Tuscaloosa sandstone's mineralogical composition and digenetic properties by observing ~500 counts. Basic lithology description of cores from The Tuscaloosa shows that the lower unit of the Tuscaloosa contains medium to coarse micaceous sandstone interbedded with shale and sandy shale. The Middle Tuscaloosa consists of dark, micaceous, and calcareous shale and is interbedded with sands. The upper part of the Tuscaloosa is characterized by medium to coarse, glauconitic, and micaceous sandstone, and it is often interbedded with micaceous clay, mudstone, and shaly sand.