Magnetic susceptibility, geochemical data from SDL section

The Miocene Climatic Optimum (MCO) disrupted long-standing cooling trend with a significant temperature rise due to elevated greenhouse gases. However, the dynamics of hydrological circulation and orbital influences during this epoch in eastern Asia remain underexplored. Employing magneto-cyclostratigraphic chronology, we analyzed samples from a 120-meter-thick section in inland Asia. Our findings highlight the profound influence of two orbital cycles on the MCO: the dominant 405-kyr eccentricity and the subtler 173-kyr obliquity band. These patterns shifted the summer movement of the Intertropical Convergence Zone in East Asia, impacting northward moisture transport. Notably, we identified six drought events correlating with global phenomena like Antarctic cooling events and the Monterey Excursion. Enhanced by latitudinal insolation gradients, our results provide insights into climate variations on both regional and global scales, with implications for past and potential future scenarios.