1.2 Myr Band of Earth‐Mars Obliquity Modulation on the Evolution of Cold Late Miocene to Warm Early Pliocene Climate

• Published in: Journal of geophysical research. Solid earth 2022-04, Vol.127 (4), p.n/a
• Main Authors: Qin, Jie, Zhang, Rui, Kravchinsky, Vadim A., Valet, Jean‐Pierre, Sagnotti, Leonardo, Li, Jianxing, Xu, Yong, Anwar, Taslima, Yue, Leping
• Format: Article
• Language: English
• Subjects: Analogs; Aridification; Asian monsoons; astrochronology; Biodiversity; Carbon; Chinese Loess Plateau; Climate change; Climate prediction; Climatology; Cooling; Earth Sciences; Geophysics; Global climate; Global warming; grand obliquity modulation; Magnetic permeability; Magnetic susceptibility; magnetostratigraphy; Mars; Miocene; Mio‐Pliocene; Modulation; Monsoons; Northern Hemisphere; Obliquity; Pliocene; red clay; Sciences of the Universe; Sediments; Shipping; Vegetation
• ISSN: 2169-9313; 2169-9356
• DOI: 10.1029/2022JB024131

The climatic transitions during the Miocene‐Pliocene epochs had significant impacts on the worldwide biological diversity and were associated with large turnovers of continental vegetation and fauna. Previous studies have shown that late Miocene cooling and continental aridification which was initiated 7 Ma reversed to warm conditions across the Miocene‐Pliocene Boundary ∼5.3 Ma. Here, we present detailed orbital pacing of Asian monsoon deposits to constrain further the global climate change during this period. We produce high‐resolution magnetic susceptibility records which reveal that the 1.2 Myr obliquity modulation would have been the main driving factor of the cooling and warming that occurred ∼7  and 5.3 Ma, respectively. The Tibetan rise and closures of the Panama and Indonesian seaways enhanced the impact of the 405 Kyr eccentricity cycles to an oscillatory climatic state while the Northern Hemisphere glaciations were increasing from 4 to 2.5 Ma. Plain Language Summary For the first time, we point out eolian sediments from Chinese Loess Plateau through the Asian monsoon is primarily respond to the long‐period evolving dynamics of Earth‐Mars obliquity modulation since the late Miocene. Our study deciphers the presence of oscillatory sedimentary patterns resulting from the 1.2 Myr band were responsible for the global climate transition during the aridification and cooling at ∼7 Ma and warming at ∼5.3 Ma. Our new discovery challenges the previous hypothesis that carbon circulations involving both the marine and terrestrial carbon reservoirs were instrumental in driving late Miocene climate cooling and warming, which provide a valuable analog for the climate prediction of Pliocene‐like temperature level in the coming decades. Key Points We investigate magnetostratigraphy and cyclostratigraphy of Chinese Loess Plateau aeolian sediments since the late Miocene The strong imprint of 1.2 Myr obliquity was responsible for the global climate transition during ∼7 Ma cooling and 5.3 Ma warming The 1.2 Myr obliquity and 405 Kyr eccentricity modulations played key roles in the paleoclimate before and after 4 Ma, respectively