Trends and Rhythms in Climate Change During the Early Permian Icehouse

Late Paleozoic deglaciation is the first icehouse‐to‐greenhouse transition in a world with expansive tropical forests, but the detailed process of this climatic upheaval is still debated due to lack of high‐precision global correlation. Here, based on the cyclostratigraphic analysis of a deep‐marine succession of Naqing in South China, chronostratigraphic correlation was achieved between Paleo‐Tethyan deep‐marine carbonate cyclicity and U‐Pb zircon age‐calibrated cyclothems from the Pangaean paleotropics. Refining the global chronostratigraphy indicates ages of 294.1 ± 0.2 Ma and 290.1 ± 0.2 Ma for the base of the Sakmarian and Artinskian stages, respectively. We juxtapose the climatic proxies and indicators across blocks and latitudes to decipher the trends and rhythms in climate change during a period from the apex of the Late Paleozoic ice age (LPIA) to the initial deglaciation. On the multiple‐million‐year time scale, the polar and equatorial climates were linked through the atmospheric pCO2 control. A rise in pCO2 promoted Gondwanan deglaciation and tropical aridification. The disparity in the inferred polarity of tropical climate changes during glacials and interglacials has been confirmed on the million‐year time scale. The meridional flux of moisture was enhanced during the minima of the ∼1.2 Myr obliquity cycle, periodically resulting in Gondwanan glaciation, glacio‐eustatic sea‐level lowerings, and reduced moisture availability in the tropical Pangaean and Paleo‐Tethyan regions. Our study provides an improved temporal resolution and understanding of the apex of the LPIA. Plain Language Summary Cyclostratigraphic analysis of the Naqing section in South China indicates ages of 294.1 ± 0.2 Ma and 290.1 ± 0.2 Ma for the base of the Sakmarian and Artinskian stages, respectively. The marine and terrestrial records across continents were synchronized using a high‐resolution global correlation. The result indicates that the climatic changes were mainly in pace with 1.2 Myr obliquity cycles superimposed on long‐term Gondwana deglaciation and tropical aridification associated with an increase of pCO2 levels. These results reinforce a solid linkage between climate changes at low and high latitudes, regardless of the ice‐sheet volume. Key Points Chronostratigraphy of Asselian and Sakmarian stages was refined by cyclostratigraphic analysis on a deep‐marine succession in South China The rise in atmospheric pCO2 promoted Gondwanan deglaciation and tropical arid