华北末次冰期D/O事件16-14的微层石笋同位素记录

虽然中国的黄土和石笋都能够像格陵兰冰芯一样记录末次冰期千年尺度气候突变事件D/O旋回，但各记录在D/O16-14的绝对年代以及其内部结构方面仍存在显著差异。这有可能是这些记录的分辨率或者年代误差不同造成的，但是也不排除存在区域气候差异或各地质记录对气候响应的不同。此外，关于末次冰期千年尺度气候突变事件D/O旋回的驱动和传输机制仍存在较大争议。这些问题的解决有待于在华北找到更多具有高精度独立年代控制的地质记录来进行详细对比。本项目拟对河北承德兴隆洞一个距今57-50ka，即D/O16-14时段的石笋样品进行230Th铀系年代学和微层年代学研究。建立相对年代较为准确的10年际分辨率的δ18O和δ13C序列，确认华北D/O16-14的绝对年代，并通过微层计数确认这些千年事件的时限和速率以及内部结构，为气候学家利用模式模拟末次冰期千年及亚千年气候突变事件的驱动和传输机制提供新的证据。

Although the loess and stalagmite in China can record the millennial climate oscillations D/O events during the last glacial period as Greenland ice core, there are still some significant differences in the ages and structures of D/O events 16-14. That may be caused by the variances of the resolution or age error among the records, however, the regional uniqueness or differences in response to climate change can not be excluded. Moreover，the drive and transmission mechansims of millennial and sub-millennial climate variations during the last glacial period are still controversial. It’s need to be verified by the establishment of more geologic records in northern China with independent and high-precision dating. Here, we propose to research on the 230Th dating, lamina-chronology, δ18O and δ13C of a stalagmite from Xinglong Cave, northern China, during 57-50kaBP (over D/O16-14). And then, we will construct 10-year-resolution δ18O and δ13C profiles with more accurate relative age and confirm the absolute chronology of D/O16-14. Moreover, we can confirm the durations and velocities of these D/O events by laminae counting, which will provide scientific basis for climatologist to model the drive and transmission mechansims of millennial and sub-millennial climate variations during the last glacial period.