【摘要】 汉中天坑群是在我国32°N湿润热带-亚热带岩溶地貌区北界首次发现的岩溶地质景观,该区域的洞穴石笋对于研究亚洲季风区古气候变化具有重要科学价值.利用陕西汉中天坑群地洞河溶洞的DDH-B15石笋开展高精度的U/Th定年和XRF微量元素扫描分析,重建该区域过去35 000-13 000yr BP的水文气候变化. XRF扫描获取的Ba/Ca、Sr/Ca、U/Ca等元素比值和V、Mn、Cr、Cu等元素离子计数记录趋势较为一致,并且与葫芦洞石笋δ¹⁸O记录的亚洲季风变化具有很强的可对比性,大致标定了H₁、H₂、H₃三次Heinrich事件,反应汉中天坑群区域水文气候变化可能受到北半球高纬度地区的影响.更多还原

【Abstract】 Hanzhong Tiankeng Group is the first karst geological landscape found in the northern boundary of Chinese 32°N humid tropical-subtropical karst geomorphic region. Cave stalagmites in this region have important scientific value for studying the paleoclimate change in Asian monsoon region. DDH-B15 stalagmite from Didonghe cave in Hanzhong, Shaanxi province is used to carry out high-precision U/Th dating and XRF trace element scanning analysis to reconstruct the past 35,000-13,000 yr BP regional hydrological and climatic changes. The ratios of Ba/Ca, Sr/Ca, U/Ca obtained by XRF scanning are consistent with the recording trends of ion counts of V, Mn, Cr, Cu, and have strong comparability with the Asian monsoon changes recorded by stalagmite δ¹⁸O from Hulu Cave. There are three Heinrich events of H₁, H₂ and H₃ roughly calibrated, reflecting that the regional hydrological and climatic changes of Hanzhong tiankeng group may be affected by high latitudes in the northern hemisphere.更多还原