East Asian Monsoon Precipitation and Paleoclimate Record Since the Last Interglacial Period in the Bohai Sea Coastal Zone, China

  • A set of conjugated strike slip faults are assessed outside the Chuan-Dian Block
  • Eastward extrusion of the Chuan-Dian Block is constrained by GPS analysis
  • Strain accumulation status before the Ludian earthquake is quantified

The Miaodao stratigraphic section (MDS) is located in the Bohai Sea, coastal zone of China, and holds historical information about regional climatic features, sea-level changes, and evolution of the East Asian monsoon. By analyzing the ages of the various sedimentary fascia, combined with proxy paleoclimatic indices [i.e., average grain size (Mz), clay + silt/sand content (SC/D), grain < 0.63 μm fraction, CIA value, and Si2O/Al2O3 and Rb/Sr ratios], we conclude that the aeolian deposit in the MDS has been directly driven by the East Asian monsoon since the last interglacial period. The grain < 0.63 μm fraction of the MDS, as demonstrated by monsoon precipitation indices, indicates multiple rainfall fluctuations in the Bohai Sea coastal zone since the last interglacial period, marine isotope stage 5e (MIS5e), when the strongest centennial-scale rainfall occurred. Evidence can be found in the stalagmite record from Shanbao Cave in the Shennongjia nature reserve. The Holocene Climatic Optimum was a period of persistent monsoon precipitation when the precipitation intensity ranked second only to MIS5e. These analyses results indicate that the MDS sediment and monsoon precipitation are controlled by the East Asian monsoon, resulting in sea-level fluctuations.

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Published by The Chinese Geoscience Union