A PALYNOLOGICAL ANALYSIS OF A SAMPLE FROM THE COON CREEK MEMBER, RIPLEY FORMATION, UNION COUNTY, MISSISSIPPI

Exposures of the Upper Cretaceous Coon creek Member of the Ripley Formation occur in Alcorn, Tippah, and Union Counties in Mississippi. Its lithology consists of dark-gray to black, fossiliferous clays and silty, micaceous sands. The Coon Creek Member is well known for its excellent preservation and diverse assortment of marine gastropods, bivalves, ammonites, crabs, and trace fossils. Its depositional environment is interpreted to be located in an intertidal to inner-shelf area. One palynological sample was collected along the Little Tallahatchie River, Union County, Mississippi. Microfossils recovered include well-preserved dinoflagellate and freshwater algal cysts, a diverse assemblage of monolete and trilete spores, bisaccates and other gymnosperms, and tricolpate, triporate, and tricolporate angiosperms. The climate was probably semi-tropical and humid, based on the abundance of pteridophyte spores, and the diversity of gymnosperm and angiosperm pollen. Dinoglagellates identified as Areoligera senonensis, Cordosphaeridium spp., and Exochosphaeridium bifidum imply an open marine environment, but the abundance of terrestrial palynomorphs suggest that the inner shelf was not far removed from a coastal mainland or barrier island system. Palynomorphs identified in this study support a Late Cretaceous likely an Early Maastrichtian age.