Abstract
The break of the Eocene latitudinal-zonal paleoclimate pattern in China is thought to correspond with the onset of East Asian monsoon (EAM). However， the transition time of the climate from latitudinal-zonal pattern to monsoonal pattern and the prevalence of monsoon have been debated intensively in past decades. Here we show lithological， geochemical and palynological data and corresponding mudstone grain size and quartz surface texture from wells in the Jiyang Subbasin Bohai Bay Basin in eastern China and comparison data in other basins. The significantly variation of precipitation and climate pattern inferred the onset and prevalence of the summer EAM in whole eastern China as early as the Late Eocene， much earlier than previously thought， and suggest that the latitudinal-zonal climate pattern was broken and transformed into a pattern of arid in western and humid in eastern China as early as 40Ma. The earliest known eolian dust in eastern China further confirmed that the winter EAM had established in the Late Eocene (ca. 40Ma). These results provide new insights into the Mid-Late Eocene climatic evolution， and challenge the previous Neogene perspective of climate pattern change and EAM prevalence.
Paper Information:
Jian Wang, Qingmeng Fu, Yingchang Cao, Jie Peng, Keyu Liu., 2026. Mid-Late Eocene climate pattern in China: Prevalence of East Asian monsoon. Journal of Earth Science. https://link.cnki.net/urlid/42.1788.P.20260519.1516.002
