Bridging the knowledge gap on the evolution of the Asian monsoon during 26–16 Ma

The evolution of the Asian monsoon from the Late Oligocene to the Early Miocene is poorly understood. Here, we first reconstruct the precipitation data of central Tibet during 26–16 million years ago (Ma), applying the coexistence approach to sedimentary pollen data, and detect an intensified Asian monsoon with ∼1.35 Ma and ∼0.33 Ma cycles. Paleoclimate modeling is used to show the importance of paleogeographic location in the development of the paleomonsoon. In addition, the results of spectral analysis suggest that the fluctuations in the Asian monsoon during 26–16 Ma can be attributed to the long-period cyclicities in obliquity (∼1.2 Ma). These findings provide climate data that can be used to understand the Asian monsoon evolution during the Late Oligocene to Early Miocene and highlight the effects of paleogeographic patterns and long-period orbital forcings on the tectonic-scale evolution of the Asian monsoon. [Display omitted] •To reconstruct the precipitation changes in central Tibet during 26-16 Ma•To depict the early evolution of Asian monsoon using the modern monsoon definition•To explain the occurrence of the paleo-monsoon by paleoclimate modeling•To reveal that long-period orbital forcings is responsible for the monsoon evolution