Palaeoclimate reconstructions on various timescales using stalagmites from Meghalaya, NE India, and applying U/Th dating, stable isotopes and element studies

洞穴提供了非常有用的古气候记录，可以准确地测定年代。在印度次大陆，到目前为止，只有很少有这样久远的记录可用。我们建议研究印度东北部的石笋，这是这些努力中的一个地区差距。在一项地面真实研究中，将应用一系列广泛的技术来了解该地区洞穴中如何记录与季风有关的气候信号。洞穴沉积物的年龄测定将在加州理工学院与J·阿德金斯合作进行。与稳定同位素(δ18O和δ13C，δ34S)平行，将应用激光烧蚀痕量元素和灰度级分析。将对石笋进行初步调查，通过结合14C和10Be研究，利用U/Th年代学和14C和10Be研究，探索其将放射性碳校准标度扩展到树轮年表范围之外的潜力。我们计划研究与碳酸盐相关的有机氮和硝酸盐。代理结果将根据气象数据进行校准。由此产生的校准结果将被用于开发同一洞穴系统洞穴中的多个气候敏感参数的记录。总体目标是在各种时间尺度上为该地区制作高质量的古气候重建图，并从气候强迫的角度解释这些重建图。

Speleothems provide very useful palaeoclimate records which can be accurately dated. On the Indian sub-continent only few such well-dated records are available to date. We propose to study stalagmites from NE India, a regional gap in these efforts. In a ground-truthing study, a broad array of techniques will be applied to understand how monsoon-related climate signals are recorded in speleothems from this region. Age determinations of speleothems will be carried out at CalTech in cooperation with J. Adkins. Parallel to stable isotope (δ18O and δ13C, δ34S), laser ablation trace element and grey-scale analysis will be applied. Pilot investigations will be conducted on stalagmites to explore their potential for extending the radiocarbon calibration scale beyond the range of tree ring chronology by using U/Th dates coupled with 14C and 10Be studies. We plan to study carbonate-associated organic N and nitrate. Proxy results will be calibrated against meteorological data. The resulting calibrations will then be applied in the development of records of multiple climate-sensitive parameters in speleothems from the same cave system. The overall goal is to produce high quality paleoclimatic reconstructions for the region on a variety of timescales, and to interpret those reconstructions in terms of climate forcing.