摘要
本文在福建东部海坛岛青峰老红砂剖面年代学框架基础上,通过2.5cm等间距高密度采样进行粒度分析,采用粒级-标准偏差方法提取敏感粒度组分,并证明敏感粒度组分平均粒径可作为东亚季风的强弱变化的替代指标,据此建立了约44.0ka以来青峰剖面老红砂记录的冬季风演变序列。结果显示,约44.0ka以来东亚冬季风经历了3个演变阶段:①44.0～25.5ka BP东亚冬季风较弱,呈现在波动中逐步增强趋势;②25.5～15.5ka BP为东亚冬季风最强盛期,并呈现高频波动特点,东亚冬季风在21.8ka BP前后达到鼎盛期;③15.5～7.1ka BP为冬季风减弱期,但在11～10ka BP前后,冬季风突然显著增强。相邻剖面平均粒径记录的冬季风演变阶段也具有较好的重复性。对比发现,青峰剖面老红砂敏感粒度组分的气候记录与长江下游葫芦洞石笋δ18 O和格陵兰GISP2冰芯δ18 O记录之间有较好的吻合,尤其对新仙女木事件和4次H事件三者都有记录,但青峰剖面对D-O旋回记录信号不明显。
The ＂ Old Red Sand＂ is been made on the origin, age and widely distributed on the coasts of laterization of the ＂Old Red Sand＂. Fujian Province. Many studies have In this paper, we focused on reconstructing the history of the Asian winter monsoon change. On the basis of granulometric analysis of samples with high-resolution, we got environmentally sensitive grain size component in Qingfeng profile by using grain size standard deviation parameter, which was proved that the selected sensitive grain size component were important proxy. The mean grain size of these environmentally sensitive components could be used to reconstruct the East Asian winter monsoon intensity. We reconstructed the history of the East Asian winter monsoon change since 44. 0 ka with three main phases. （1） In 44. 0--25.5 ka BP, the East Asian winter monsoon was relatively weak and increased gradually during fluctuating; （2） In 25.5--15.5 ka BP, the East Asian winter monsoon was the strongest with high-frequency fluctuation; （3） In 15.5--7.1 ka BP, the East Asian winter monsoon was weak but remarkably enhanced during 11-- 10 ka BP. The East Asian winter monsoon recorded by mean grain size of the two neighboring sections had a good repeatability, so oscillation at the millennial scale should be a reliable signs of the East Asian winter monsoon intensity. There was a good consistency in climate change recorded by sensitive grain size components in the QF section and the stalagmites δ^18O of Hulu Cave and Greenland GISP2 ice core, especially the Younger Dryas events and four Heinrich events were recorded bu the three proxies, but the signal of D-O cycles was relatively weak.
出处
《中国沙漠》
CSCD
北大核心
2013年第2期443-452,共10页
Journal of Desert Research
基金
国家自然科学基金项目(41271031)
黄土与第四纪地质国家重点实验室开放基金项目(SKLLQG1113)
福建省自然科学基金项目(2009J01208)
福建省公益类科研院所专项基金(2010R1037-3)共同资助
关键词
老红砂
敏感粒度组分
东亚冬季风
HEINRICH事件
Old Red Sand
environmentally sensitive grain size components
East Asian winter monsoon
Heinrich event
