Evolution of atmospheric circulation across the Cretaceous-Paleogene (K-Pg) boundary interval in low-latitude East Asia

The Cretaceous-Paleogene (K-Pg) boundary interval is an important time interval for deep-time paleoclimatic research, and most records of this interval are derived from marine sections. In this study, we conduct high-resolution magnetic and geochemical analyses in a terrestrial sedimentary succession from the Nanxiong Basin (Southeast China). We combine this data with previous work to compare these results with global marine and other terrestrial records. We find that the magnetic and geochemical parameters record a sequence of global climatic changes across the K-Pg boundary interval. Moreover, during the Maastrichtian cold "greenhouse" time interval, the climate changes in the studied area are consistent with the benthic foraminiferal δ¹⁸O record from the North Atlantic, and we observe no correlation between the δ¹³C_carb and δ¹⁸O_carb; in contrast, during the Danian "greenhouse" time interval, the climate changes in the studied area are consistent with the benthic foraminiferal δ¹⁸O records from both the Pacific and the North Atlantic, and we observe a positive correlation between δ¹³C_carb and δ¹⁸O_carb. We suggest that the observed changes are likely linked to the transformation of atmospheric circulation in low-latitude East Asia. These new insights have implications for "global monsoon" research and understanding the causes of the mass extinction