FAUNAL CHANGES ASSOCIATED WITH CARBONATE PROGRESSION IN THE FORT PAYNE FORMATION OF CENTRAL TENNESSEE

The Fort Payne Formation in Central Tennessee includes a variety of Late Osagean faunas and facies. The Lower to Middle Fort Payne is dominated by a basin-fill sequence, represented by the green shale facies characterized by proteid trilobites, thin-shelled brachiopods and the conulariid Paraconularia byblis. The Upper Fort Payne is a base-of-slope to slope sequence, also represented by the green shale facies that is consistently interrupted by the deposition of crinoidal sheet-like packstones. The green shales in the Upper Fort Payne are marked by an abundant, higher diversity fauna, which consists of disparid crinoids, productid brachiopods, fenestrate and rhomboporid bryzoans, and the conulariid Paraconularia missouriensis (which seems to grow on the packstone surfaces). The sheet-like packstone facies are turbidites and or tempestites characterized by an abundance of camerate crinoids and spiriferid brachiopods, apparently washed down slope from a carbonate platform. The changes in facies and faunal assemblages correlate to a progression from a basin-fill sequence to a carbonate platform environment, as the Fort Payne Formation grades into the overlying Warsaw Limestone.