洞穴滴水-CaCO_3体系氧碳同位素组成的气候意义研究现状和问题  

Research Status of Climatic Implications of Oxygen and Carbon Isotopic Compositions in Cave Drip Water-Carbonate Systems

作　　者：李玲珑[1] 刘再华[1] 

机构地区：[1]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550002

出　　处：《地球与环境》2015年第2期223-232,共10页Earth and Environment

基　　金：国家自然科学基金(41172232)

摘　　要：近年来,通过对洞穴滴水-CaCO3体系各项指标的长期监测,以了解现代碳酸钙沉积的形成机制成为了石笋古气候研究的重点。尤其是对滴水-CaCO3体系氧同位素组成(δ18 O)的研究取得了显著的进展。人们在对滴水和CaCO3的δ18 O与古温度关系的研究中,不断地修改普遍使用的关系式,甚至提出了适合自身研究区石笋δ18 O与温度的关系式。无疑这将增加利用石笋氧同位素组成重建本地区古温度的可信度。在对碳同位素组成(δ13 C)的研究中,学者们更加细致地研究了各种影响滴水δ13 C值的因素(如先期碳酸盐沉积PCP、通风条件等),为更好地利用石笋δ13 C重建古气候环境提供了科学支撑。由于洞穴监测条件的限制,至今大多数洞穴都未能建立起完善的自上而下的监测体系,所以对一些δ18 O、δ13 C变化的解译仍然存在多解性和不确定性,有待未来的研究继续加强。In recent years,monitoring drip water-CaCO3 systems in karst caves to understand the forcing mechanisms of modern calcite has become the focus in speleothem paleoenvironmental research.Especially,the study on oxygen isotope compositions has achieved considerable progress.In the study on the relationship between CaCO3δ18 O and temperature,researchers modified the commonly used equations continuously,and even put forward their own equations which are more appropriate to their research areas,and thus increased the accuracy and confidence level of the calculated paleotemperature.In the study on carbon isotopes,researchers studied various influences on theδ13 C values in more detail（such as PCP,Ventilation）,which provide a scientific support to reconstructing the paleoclimate with the speleothemδ13 C values.However,due to complex drip water-CaCO3 systems,the integrated monitoring systems haven＇t set up in most cases.Therefore,there is high uncertainty in climatic interpretation of carbon and oxygen isotopic compositions need to be solved in future researches.

关 键 词：滴水-CaCO3体系 氧碳同位素组成 先期碳酸盐沉积 平衡分馏 动力分馏 石笋古气候重建 

分 类 号：P597[天文地球—地球化学] X142[天文地球—地质学]