董进国, 董梦彩, 熬贵福, 黄姜楠. MIS3以来黄土高原东南部石笋阶段性沉积记录的夏季风演化[J]. 海洋地质与第四纪地质, 2018, 38(5): 171-177. DOI: 10.16562/j.cnki.0256-1492.2018.05.016
引用本文: 董进国, 董梦彩, 熬贵福, 黄姜楠. MIS3以来黄土高原东南部石笋阶段性沉积记录的夏季风演化[J]. 海洋地质与第四纪地质, 2018, 38(5): 171-177. DOI: 10.16562/j.cnki.0256-1492.2018.05.016
DONG Jinguo, DONG Mengcai, AO Guifu, HUANG Jiangnan. Variation of East Asian summer monsoon since MIS3 recorded by an absolutely-dated stalagmite from north China[J]. Marine Geology & Quaternary Geology, 2018, 38(5): 171-177. DOI: 10.16562/j.cnki.0256-1492.2018.05.016
Citation: DONG Jinguo, DONG Mengcai, AO Guifu, HUANG Jiangnan. Variation of East Asian summer monsoon since MIS3 recorded by an absolutely-dated stalagmite from north China[J]. Marine Geology & Quaternary Geology, 2018, 38(5): 171-177. DOI: 10.16562/j.cnki.0256-1492.2018.05.016

MIS3以来黄土高原东南部石笋阶段性沉积记录的夏季风演化

Variation of East Asian summer monsoon since MIS3 recorded by an absolutely-dated stalagmite from north China

  • 摘要: 基于山西龙洞8个铀钍年代和100个氧同位素数据(δ18O)重建了深海氧同位素(MIS)3阶段以来东亚夏季风演化历史。石笋L8沉积并不连续,主要生长在58.0~54.5, 27.1~18.0和6.8~3.9kaBP 3个阶段。不同于季风边缘区其他洞穴记录,石笋δ18O值在24.5kaBP突然增加1‰,表明MIS2早期内陆地区经历了一次显著的弱季风过程,可能响应于北大西洋Heinrich 2事件。石笋δ18O序列伴随着轨道尺度太阳辐射的变化,晚全新世δ18O值持续偏重意味着低纬热带辐合带逐步南移,导致北方地区夏季风降水持续减少。Dansgaard-Oeschger(D-O)15事件具有明显的双峰结构,与格陵兰冰心记录的亚千年尺度温度波动几乎同步变化。

     

    Abstract: The high-resolution oxygen isotope sequence established upon 100 oxygen isotope samples and 8 230Th dates from the Dragon Cave, Shanxi province, north China, provides a detailed history of East Asian summer monsoon (EASM) variation since Marine Isotope Stages (MIS) 3. The sample L8 grew discontinuously during the periods from 58.0 to 54.5 kaBP, 27.1 to 18.0 kaBP, 6.8 to 3.9 kaBP, respectively. On the orbital scale, the long-term trend of the δ18O record generally follow the North Hemisphere Insolation changes. However, the L8 δ18O value abruptly increased by 1‰ at 24.5 kaBP, indicating an abrupt weak monsoon event possibly associated with the Heinrich event 2 in the North Atlantic region. Moreover, gradual enrichment of δ18O since ~ 6 kaBP also indicates steadily weakening of EASM, responding to southward retreat of the Intertropical Convergence Zone. During the early MIS3, our record shows two millennial-scale strong summer events, analogous in timing and structure to the Greenland Dansgaard-Oeschger events 16-15. The latter event (DO15) exhibits two distinct phases, consistent with the centennial shifts in Greenland temperature changes. This relationship reveals a tight coupling between high- and low-latitude climates at sub-millennial scales, implying a role of the large-scale ocean- atmosphere circulation in linking Greenland temperature and the Asian monsoon.

     

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