Petrology, Provenance, and Depositional Setting of the Lower Tallahatta Formation (Meridian Sand) in Grenada County, Mississippi

The Meridian Sand represents the lowermost member of the Middle Eocene Tallahatta Formation, which is found in the Gulf Coast region of the United States. Five stratigraphic sections in Grenada County were measured and described. Twenty-one sand and sandstone samples, and 2 mud samples were collected from all sections. Textural analyses were performed on all 23 samples to determine their lithologic properties. Petrographic descriptions and modal analyses were performed on thin sections made from the 21 sand and sandstone samples, and 400 grains were point counted in each sample. Geochemical analyses were carried out on all sand, sandstone, and mud samples using X-ray fluorescence (XRF) to identify elemental composition. X-ray diffraction (XRD) analyses were conducted to characterize the mineralogical composition of mud samples. Nine lithofacies were defined based on lithologic properties, and field observations. The general lithology of the Meridian Sand in Grenada County is very fine to coarse, angular to sub-angular, poorly to moderately well-sorted sand and sandstones, and it is often interbedded with mud beds. Quartz is the most dominant mineral, and it composes more than 90% of the framework grains in all sands and sandstones. The sands and sandstones were classified according to Dott’s (1964) classification as quartzarenites, sublitharenites, quartzwackes, and lithicgraywackes