Strontium isotopic signature of hydrothermal sedimentation from Early Cambrian barite deposits in east Guizhou, China

• Published in: Chinese science bulletin 2004-12, Vol.49 (24), p.2632-2636
• Main Authors: Xia, Fei, Ma, Dongsheng, Pan, Jiayong, Sun, Zhanxue, Cao, Shuanglin, Nie, Wenming, Wu, Kai
• Format: Article
• Language: English
• Subjects: Barite; Cambrian; Chemical analysis; Deposits; Isotope ratios; Isotopes; Mineralization; Pyrite; Seawater; Sedimentation; Sedimentation & deposition; Strontium; Strontium 87; Strontium isotopes; Water analysis; 化学分析; 沉积物; 重晶石; 锶同位素
• ISSN: 1001-6538; 2095-9273; 1861-9541; 2095-9281
• DOI: 10.1360/04wd0254

The ore genesis model for barite deposits in east Guizhou Province has been in dispute and the major debate focuses on whether they are product of the submarine hydrothermal sedimentation. This note presents new strontium isotope data from 19 samples of Dahebian and Yuping barite deposits, and their ^87Sr/^86Sr ratios are significantly lower than that of the coeval seawater. The ^87Sr/^86Sr ratios of 17 samples out of 19 samples rang from 0.708310 to 0.708967, indicating that they might be related to the mantel admixture. Two isotopic ratios in this study are higher than those of coeval seawater (0.7090), collected from late-stage barite mineral vein of interpenetrative strata and a barite nodule bearing hypidiomorphic granular pyrite, which indicates that they might be related to the continental admixture. The study provides Sr isotopic evidence not only for the submarine hydrothermal exhalative genesis of Dahebian and Yuping barite deposits, but also for distinguishing the barite mineralization of late stage.