The 173‐kyr Obliquity Cycle Pacing the Asian Monsoon in the Eastern Chinese Loess Plateau From Late Miocene to Pliocene
Rui Zhang, Xiaojuan Li, Xu Yong, Jianxing Li, Lu Sun, Leping Yue, Feng Pan, Feng Xian, Xiaohao Wei, Yuge Cao
Abstract
Abstract We conduct magnetostratigraphy and cyclostratigraphy on an eolian red clay sequence spanning 7–3.1 Ma in the eastern Chinese Loess Plateau. We pay more attention to the unconventional 173‐kyr obliquity modulated cycle which is associated with the secular frequency interference of orbital inclinations between Earth and Saturn. Similar to the 405‐kyr eccentricity cycles, the 173‐kyr obliquity band proved to be an important orbital driving component by the latest astronomical findings, and can serve as a chronometer of terrestrial air circulation reconstruction back to 7 Ma. Comparison with magneto‐cyclo‐bio‐stratigraphic timescales of another noted eolian sequence from the adjacent area, the 173‐kyr cycle is exceptionally presented as a robust recognition of the cyclical sedimentary patterns for the East Asia monsoon deposits.