ISOTOPIC EVALUATION OF DIAGENETIC ALTERATION IN PALEOSOL CARBONATE FROM THE UPPER PENNSYLVANIAN CONEMAUGH FORMATION, OHIO

Upper Pennsylvanian rocks in Ohio are comprised of alternating units of bedded shale, coal, calcic vertic paleosols, lacustrine limestone, and marine limestone. These units contain carbonates with different origins and that possess various isotopic signatures. Therefore, these rocks present an ideal opportunity to test for potential diagenetic alteration of soil carbonate and assess whether Paleozoic soil carbonates, especially those underlying marine and lacustrine limestones, can be used for paleo-PCO2 estimates. We analyzed carbon and oxygen isotopes in carbonate from shales, paleosols, and limestones to distinguish primary soil carbonate from carbonate precipitated since burial. We also measured carbon isotopes in organics from paleosols (coal and within soil carbonate nodules) to identify the abundance and isotopic composition of organic matter and determined 87Sr/86Sr isotopes from all carbonates to identify potential mixing and reprecipitation of carbonates when shallow water bodies (oceanic and lacustrine) were overlying these rocks.