我国某些元古宙及早寒武世碳酸盐岩石的锶同位素组成

87Sr/86Sr DATA FOR SOME MIDDLE-LATE PROTEROZOIC TO EARLY CAMBRIAN CARBONATE ROCKS IN CHINA

本文报道了我国某些元古宙及早寒武世碳酸盐岩石锶同位素的测定结果。样品采自蓟县中元古界和峡东震旦-寒武系标准剖面,共46件样品54个测定数据。样品分析分别在澳大利亚国立大学和宜昌地质矿产研究所同位素实验室进行。取得的测定数据经空白校正和年龄校正,最后给出样品形成时^(87)Sr/^(86)Sr的初始值。测定中用NBS—987和NBS—607标准物质监控仪器状态和分析过程,得到的^(87)Sr/^(86)Sr值的精度好于0.03％。

This paper reports the results of determination of 87Sr/86Sr ratios of some Middle-Late Pro-terozoic and Early Cambrian carbonate rocks in China. The samples were collected from the standard sections of the Middle Proterozoic in Jixian and the Sinian-Early Cambrian in the East Yangtze Gorges respectively. The sample analyses were carried out in the isotopic geology laboratories in Australian National University and the Yichang Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences. The data obtained were corrected for the Rb blank and the radiogenic 87Sr from87Rb decay. Finally the initial 87Sr/86Sr ratio for the formation of the samples was given. The reference materials of NBS-987 and NBS-607 were used for monitoring the instrument condition and the analytical process. The precision of the measured 87Sr /86Sr ratio is better than 0. 03%.A brief discussion is also made on the obtained data.