摘要
湖泊化学沉积碳酸盐δ18O是研究区域气候演变的重要环境指标之一。青海湖等闭流湖泊的研究结果证实,在对δ18O环境记录进行共生碳酸盐氧同位素分馏效应校正时,应依据具体情况,采用0-1‰的分馏差值。由高温实验结果推断出的常温分馏差值(4‰-7‰)不能被应用到自然条件下湖泊共生碳酸盐氧同位素分馏效应的校正。
δ^(18)O of lacustrine inorganic carbonates is one of the important environmental proxies for the study of regional climatic evolution.Results from Lake Qinghai and other closed-basin lakes indicate that isotope fractionation between co-existing carbonates formed naturally in lake environments is minimum.The fractionation differences of 4‰~7‰ in δ^(18)O between dolomite and calcite,obtained based on elevated-temperature experiments and extrapolations to temperatures at 20℃~25℃,are not applicable to the carbonates formed in natural environments.The fractionation differences of 0~1‰ are recommended for calibrating a possible disparity between co-existing carbonates in lacustrine isotopic records.
出处
《盐湖研究》
CSCD
2004年第2期14-18,共5页
Journal of Salt Lake Research
基金
中科院青海盐湖所创新领域前沿项目(CX200302)
国家自然科学基金面上项目(49971074)
中科院资环创新重大项目(KZCX1-Y-05)
关键词
共生碳酸盐
氧同位素分馏
沉积学
环境同位素
Environmental isotope
Co-existing carbonates
Oxygen isotopic fractionation
Lake Qinghai