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

使用印度东北部梅加拉亚邦的石笋，并应用 U/Th 测年、稳定同位素和元素研究，重建不同时间尺度的古气候

• 批准号: 160104861
• 负责人: Professor Dr. Gerald Haug
• 金额: --
• 依托单位: Sektion 4.3: Klimadynamik und Landschaftsentwicklung
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/160104861?language=en
• 关键词: Palaeoclimate; reconstructions; various; timescales; using

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.

洞穴化石提供了非常有用的古气候记录，可以准确地确定年代。在印度次大陆上，迄今为止只有很少的记录是准确的。我们建议研究来自印度东北部的石笋，这是这些努力的区域差距。在一项实地调查研究中，将应用一系列广泛的技术来了解季风相关的气候信号是如何在该地区的洞穴中记录下来的。洞穴化石的年龄测定将在加州理工学院与J. Adkins合作进行。平行于稳定同位素（δ18O和δ13C， δ34S），激光烧蚀微量元素和灰阶分析。将对石笋进行试点调查，以探索其利用U/Th日期结合14C和10Be研究将放射性碳校准尺度扩展到树木年轮年表范围之外的潜力。我们计划研究碳酸盐岩伴生有机氮和硝酸盐。代理结果将根据气象数据进行校准。然后，由此产生的校准将应用于同一洞穴系统中洞穴主题中多种气候敏感参数的记录的开发。总体目标是在各种时间尺度上对该地区进行高质量的古气候重建，并根据气候强迫对这些重建进行解释。