冷泉碳酸盐岩Sr同位素示踪研究进展

在冷泉的研究中，确定富甲烷流体的来源是非常重要的，Sr同位素对流体来源、混合模式和水岩反应等具有很好的示踪作用。近年来，国际上对冷泉碳酸盐岩Sr同位素的示踪研究越来越关注。本文系统总结了现代和古代冷泉碳酸盐岩Sr同位素的研究进展，简要归纳了Sr同位素分析测试方法，并对化学前处理过程中采用的不同酸溶液溶解样品的方法进行了对比，指出了建立标准化学前处理方法的必要性。现代和古代冷泉碳酸盐岩Sr同位素组成的变化范围较大，不同碳酸盐矿物具有不同的Sr同位素特征。冷泉碳酸盐岩Sr同位素的示踪研究集中在现代和古代冷泉流体来源的定性研究、混合流体来源的定量模型计算、以及古代冷泉碳酸盐岩的Sr同位素定年等方面。尽管取得了一系列进展，但是定量计算端元流体混合比例的准确性还有待提高，同时利用Sr同位素对古代样品进行定年存在不确定因素，其适用条件也需要进一步研究。

Research advances of Sr isotope tracer for cold seep carbonates

Determination of the origin of methane- rich fluids is an important issue in study of cold seep. Sr isotope as a tracer can reflect fluid sources, fluid mixing and fluid- rock reactions. In recent years, Sr isotope of cold seep carbonates has recieved much worldwide attention. This paper summarized the research progress of Sr isotopes of modern and ancient cold seep carbonates, including the testing methods of Sr isotope and preprocessing method comparison of sample dissolution using different acid solution, and finally pointed out the necessity of establishing the standardized processing methods. The Sr isotopic compositions of modern and ancient seep carbonatic rock vary significantly with different carbonatic minerals. The study of Sr isotope tracer of cold seep carbonates mainly focused on the following aspects: qualitative examination of modern and ancient seep fluid sources, quantitative model calculation of mixed fluid sources, and 87Sr/86Sr isotopic dating of fossil methane seep carbonates. Although a series of progress was achieved, the accuracy of fluid mixing ratios using quantitive calculation of end members needs to be improved. Meanwhile, the uncertainties still occur in Sr isotopic dating for fossil seep carbonates, and thus its application conditions need further to study.