Abstract

A low diversity crinoid fauna from the Nada Member of the Borden Formation in northeastern Kentucky includes species typical of the upper Burlington Limestone of the standard Mississippian section in eastern Iowa. The Nada Member records a delta platform environment stratigraphically above delta slope beds of the Cowbell Member of the Borden and is thus environmentally equivalent to the Edwardsville Formation of the Borden Group farther west in north-central Kentucky and southern Indiana. The Edwardsville is equivalent to the Keokuk Limestone of the standard section and is thus younger than the Nada, demonstrating time-transgressive progradation of the Borden Delta from east to west. Important crinoid species from the Nada include Uperocrinus pyriformis (Shumard), Macrocrinus konincki (Shumard), Dorycrinus quinquelobus (Hall), Eretmocrinus calyculoides (Hall) and Gilbertsocrinus tuberculosus (Hall), all typical upper Burlington species.--Modified journal abstract.

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