Details

Autor(en) / Beteiligte

• Zhang, Rui
• Li, Xiaojuan
• Xu, Yong
• Li, Jianxing
• Sun, Lu
• Yue, Leping
• Pan, Feng
• Xian, Feng
• Wei, Xiaohao
• Cao, Yuge

Titel

The 173‐kyr Obliquity Cycle Pacing the Asian Monsoon in the Eastern Chinese Loess Plateau From Late Miocene to Pliocene

Ist Teil von

• Geophysical research letters, 2022-01, Vol.49 (2), p.n/a

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• 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. Plain Language Summary In addition to astronomical rhythms associated with the amplitude modulations (AM) of Earth's precession cycles (405‐kyr long eccentricity and 100‐kyr short eccentricity), quantified the proportion of variance in macroevolutionary time series that can be also explained by AM of obliquity (most important ones are 1.2‐Myr Earth‐Mars and 173‐kyr Earth‐Saturn cycles). However, obliquity modulations have not been considered in the eolian sediments of Chinese Loess Plateau (CLP), although a number of data sets have been presented to confirm changes in the climate‐related to the obliquity modulation which is in recent astronomical solutions and geological records. Our study deciphers astrochronological cycles recorded in the eolian sediments of the eastern CLP, we point out the presence of cyclic sedimentary patterns resulting from modulated obliquity were also responsible for the alternation of decreasing and increasing phases of aridification and precipitation during the late Miocene to Pliocene. Our climate proxy demonstrates the 173‐kyr long cycle that appears in the monsoon system is a key to revealing the leading causes in long‐term monsoon variations. Our discovery improved the previous hypothesis that only the 405‐kyr long eccentricity were instrumental in driving late Miocene to Pliocene climate. Key Points An integrated magnetostratigraphic and cyclostratigraphic study was performed from eastern Chinese Loess Plateau spanning the Miocene‐Pliocene transition We observed the strong imprint of the 173‐kyr cyclicity of orbital inclination rates between Earth and Saturn for the first time As contributions to the Asian monsoon system, obliquity and eccentricity modulations both play key roles in terrestrial paleoclimate