通过对我国蓟县和峡东典型地层剖面中、晚元古界沉积的海相碳酸盐岩、磷块岩和硅质岩中的微量硫酸盐提取和硫同位素测定，来确定中、晚元古代海水硫酸盐的同位素年代曲线。所获的高分辨、连续的中、晚元古代海水年代将详细记录当时海洋的硫同位素变化，这对深入探讨全球晚前寒武纪的海洋、大气、生物及生命的演化和地质事件具有重要意义。

The first secular age curve of sea-water sulfur isotope with high-resolution, from ca. 1700Ma to ca. 540Ma, has been firstly established in the world by means of extraction of trace sulfate from carbonate rocks in two standard stratigraphic sequences of Middle and Late Proterozoic in China, which are mainly composed of carbonates and located in Jixian county and Yichang city, respectively. In addition, the synchronously carbon isotopic age curve of sea-water has been obtained from the same sections. The secular trends of sulfur and carbon isotopic variations in the ancient sea-water and their relationships with atmospheric, oceanic, and biological evolutions, as well as global event and tectonic movement have been discussed preliminarily.