HIGH RESOLUTION CARBON ISOTOPE STRATIGRAPHY OF THE COUNCIL GROVE AND CHASE GROUPS; EXAMINING THE ASSELIAN-SAKMARIAN BOUNDARY IN THE HUGOTON BASIN (SOUTHWESTERN KANSAS)

Carbon isotope stratigraphy from the Asselian and Sakmarian Stages (Cisuralian Series, lower Permian) in the Newby 2-28R core from Stevens County, Kansas reflects the rise and fall of sea level showing the expansion and contraction of glacial mass on carbon cycling. Strata from the Council Grove and lowest interval of the Chase Groups vary between fossiliferous limestones, correlating to intervals of deep water and low glacial mass, and calcareous red siltstones, correlating to lower sea level and increased glacial mass. Lithologies interpreted to be higher sea level consistently show elevated δ¹³C_carb values when compared with shallow water intervals just above or below, showing as much as a 6 ‰ shift within 10s of meters. This basin does not record the newly described δ¹³C_carb excursion as seen in China and Nevada across the Asselian-Sakmarian boundary, implying a limited connection with the open ocean. Whereas absolute values in this basin are generally lower than average values seen elsewhere, it is likely that this curve is a powerful tool to use for correlation within the Hugoton Basin and the North American midcontinent.