ALBERT

Description: The Mississippian section of the United States mid-continent Anadarko Basin (Oklahoma and Kansas) has been a prolific hydrocarbon reservoir since the 1920s, yet large-scale regional correlations between individual stratigraphic units remain difficult because of the complex and heterogeneous nature of the carbonate facies. New sedimentologic and carbon isotopic data from a nearly continuous Mississippian core (Pan American 1 Albert Severin) from the Anadarko Basin, Oklahoma (Garfield County), United States, provides insight into the potential of carbon-isotope chemostratigraphy as a correlation tool in complex stratigraphic successions for which biostratigraphic data are not available. The carbon isotopic composition ( $${\delta }^{13}\mathrm{C}$$ ) of whole-rock samples was analyzed to determine if stratigraphic trends reflect global changes in the carbon cycle. A large positive shift (+5.6) in the lower Tournaisian (Kinderhookian), consistent values (averaging +2.3) in the upper Tournaisian through middle Viséan (upper Kinderhookian–Meramecian), and a negative shift (–2.3) in the uppermost Viséan (lower Chesterian) correspond to trends in the carbon isotopic compositions ( $${\delta }^{13}\mathrm{C}$$ values) from other regional data sets, including the global type section at Arrow Canyon, Nevada. Further analysis of the data reveals that isotopic compositions are not facies dependent, suggesting that marine chemistry and depositional changes in the Anadarko Basin reflect global environmental changes during the Mississippian. These inferences demonstrate the potential of the Pan American 1 Albert Severin core to be a Mississippian-type section for the Anadarko Basin, and that stable-isotope chemostratigraphy can be used as a correlation tool to better understand the subsurface in complex successions, such as the Mississippian limestone of the United States mid-continent.