TOURNAISIAN CONODONT BIOSTRATIGRAPHY OF THE TYPE KINDERHOOKIAN AREA OF IOWA, ILLINOIS, AND MISSOURI

The type area for the Kinderhookian (Lower Tournaisian) is located in the tri-state area of southeastern Iowa, western Illinois, and northeastern Missouri. A variety of lithostratigraphic units are present throughout the area with significant nomenclature divides between the Iowa succession and the units farther southeast, which has historically complicated precise chronostratigraphic correlation. Refining the stratigraphic correlation between these units will allow for an improved sea level interpretation of the Kinderhookian.

For this study, high resolution conodont biostratigraphy was undertaken in tri-state area, specifically southeastern Iowa and northeastern Missouri. The lithostratigrahpic units investigated include the English River Fm., McCraney Fm., Prospect Hill Fm., and the Starrs Cave and upper members of the Wassonville Fm. from Starrs Cave Park and Preserve, Crapo Park, Stony Hollow, and the H-28 core from Iowa; along with the Hannibal Shale at its type section in Missouri. Conodont samples from this study area returned a diverse fauna including important species of Siphonodella that range from the duplicata Zone to at least the lower crenulata Zone. These data demonstrate that the McCraney Fm. through Wassonville Fm. interval of southeastern Iowa are correlated with the Hannibal Shale in Eastern Missouri and western Illinois. The Kinderhookian stratigraphic succession records a number of sequence packages likely deposited during multiple glacial-eustatic sea level cycles during the Early Carboniferous Ice-House.