华北倒二冰消期的气候变率及相位关系：高分辨石笋记录

项目名称： 华北倒二冰消期的气候变率及相位关系：高分辨石笋记录

项目编号： No.41472150

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 地质学

项目作者： 谭明

作者单位： 中国科学院地质与地球物理研究所

项目金额： 102万元

中文摘要： 自从Devils Hole方解石脉的氧同位素序列发表以来，倒二冰消期的因果问题、阶段性问题以及气候变率问题不断被新的古气候记录提出并刷新。过去数年，来自东亚季风区中国南方的高精度定年石笋记录为冰期终止机理的分析和讨论提供了新的年代框架，同时也发现了石笋记录本身、以及石笋记录与其他记录之间在倒二冰消期不吻合。如何进一步理解和回答这些问题？从东亚季风区另一关键区域华北获得新记录是希望之一。申请者最近获取的河北兴隆洞石笋XL-4跨完整倒二冰消期时段，无沉积间断，初步定年分析表明其铀系年代精度优于0.5%。若稳定同位素分析采用Micromill精确取样，可实现13个样/mm，平均分辨率达到5a。在建立具有精确时标的高分辨稳定同位素序列基础上，揭示倒二冰消期华北的气候变率与相位关系，将有助于对高低纬相互作用，及内外力驱动关系等重大科学问题的理解，并有助于解决因果难题。

中文关键词： 倒二冰消期；华北；气候变率；相位关系；石笋记录

英文摘要： A series of questions about the penultimate deglaciation have continuously been raised by emerging paleoclimate data since the launch of the oxygen isotope sequences of calcite veins from Devils Hole, such ascausality problem, one or two phase problem, variability problem and so on. The problems of the penultimate deglaciation have become relatively independent paleoclimate research branch. Over the past years, high-precision dating of stalagmite records from the South China of the East Asian monsoon region provides a new time framework for the analysis and discussion on the mechanism of glacial termination, but also reveals many discrepancies between stalagmite records themselves, as well as with other records. It could gives us hope to understand and answer these questions to obtain new records from northern China, another key area of the East Asian monsoon region. Here we propose the stalagmite XL-4 from Xinglong Cave located in northern China, which covers the complete penultimate deglaciation with no hiatus. The preliminary analysis indicates that the precision of its uranium series dating is better than 0.5%. And moreover, it could be expect to improve the precision by enlarging sample size. With accurately sampling using Micromill, stable isotope analysis could be able to mill up to 13 subsamples/mm, it means that the average resolution of the time series could be reached 5a. Based on the establishment of high-resolution stable isotope sequence controlled by precise time scale, this stalagmite record will reveal climate variability and phase relationship (with respect to insolation and other records) during the penultimate deglaciation in northern China, which may help to understand some major scientific questions such as the interaction between high and low latitude, the relationship between internal and external forces, as well as the solution of the causality problem.

英文关键词： penultimate deglaciation;northern China;climate variability;phase relationship;stalagmite record