Sedimentary facies and carbon isotopes of the Upper Carboniferous to Lower Permian in South China: Implications for icehouse to greenhouse transition

Abstract

The Late Paleozoic Ice Age (LPIA) is the so far longest-last icehouse climate state during the Phanerozoic, and recorded a complete transition from icehouse to greenhouse climate state since the occurrence of vascular plants and complex terrestrial ecosystem. Therefore, integrated studies on the icehouse-greenhouse transition of the LPIA are critical to understanding the driver and mechanism of the deep-time paleoclimate system, particularly in an icehouse climate state. However, frequent subaerial exposures and stratigraphic discontinuities in low-latitude areas due to glacio-eustatic changes from the Pennsylvanian (Late Carboniferous) to Cisuralian (Early Permian) potentially altered the primary δ13C signals, which hampered a valid global correlation. Here, three carbonate slope successions (Naqing, Shanglong, and Narao) in the Luodian Basin, South China Block, were selected for detailed sedimentology and high-resolution carbonate δ13C study. The variation of δ13C is compared with the sedimentary characteristics and can be correlated with global glacial events and atmospheric pCO2 during the apex and deglaciation period of the LPIA. It suggests that δ13C of the Luodian Basin can potentially represent the global mean δ13C of the seawater dissolved inorganic carbon and provide a reference for the future study on global carbon cycling.