HIGH-RESOLUTION CARBON ISOTOPE COMPOSITE CURVE FOR THE PERMIAN SYSTEM: IMPLICATIONS FOR ORGANIC CARBON BURIAL AND GLOBAL CLIMATE

More than 1,000 marine carbonate carbon isotope (δ¹³C_carb) samples from two measured sections in the Pequop Mountains, Nevada, USA and one section at Tieqiao, near Laibin, Guangxi Province, China were analyzed to create a biostratigraphically well-constrained, high-resolution composite δ¹³C_carb curve for the Permian System. Samples were collected in conjunction with conodont biostratigraphic sampling and from sections with well-established foraminiferal biostratigraphic control. The high-resolution data presented here demonstrate that there is significant structure to the Permian δ¹³C_carb curve, including both discrete positive and negative δ¹³C_carb excursions.

Because previously published Permian δ¹³C_carb curves are of relatively low resolution compared to our work, particularly for the Cisuralian and Guadalupian series, many of the events from these intervals identified by this study remain to be demonstrated elsewhere, and require verification before they can be demonstrated to be global events. However, some of the events from the uppermost Guadalupian and Lopingian identified here have been documented from other localities, which supports the global significance of these events.

This δ¹³C_carb record has the potential to act as a powerful stratigraphic tool for correlation in the Permian. Additionally, our new curve may be used to evaluate the relative timing of changes in carbon cycling with respect to oceanographic and climatologic events.