滇西兰坪盆地膏盐微量元素、同位素地球化学特征及意义  

The Trace Elemental and Isotopic Characteristics of Gypsum and Its Significance in the Lanping Basin,Western Yunnan

作　　者：杨志娟 朱志军[1] 丁婷 杨浩 王何均 田原 吴金阳 严锦洁 YANG Zhijuan;ZHU Zhijun;DING Ting;YANG Hao;WANG Hejun;TIAN Yuan;WU Jinyang;YAN Jinjie(College of Geosciences,East China Institute of Technology,Nanchang,330013,China)

机构地区：[1]东华理工大学地球科学学院,江西南昌330013

出　　处：《盐湖研究》2024年第1期76-87,共12页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(42362018,U0933605)。

摘　　要：滇西兰坪盆地中多数金属矿床伴生大量膏盐体,为了探讨膏盐体与金属成矿关系,对膏盐体进行了微量元素和同位素地球化学分析。发育在云龙组中呈层状黑色石膏稀土总量,δEu(0.87)和δCe(0.95),^(87)Sr/^(86)Sr(0.708629~0.710189),δ^(34)S_(V-CDT)(9.6‰~+11.9‰)与区域云龙组地层地球化学特征相近;分布在云龙组地层中呈蘑菇状、指状侵入的块状石膏的稀土总量,δEu(0.65)和δCe(0.85),^(87)Sr/^(86)Sr(0.707695~0.708127),δ^(34)S_(V-CDT)(+12.6‰~+15.4‰)与晚三叠世三合洞组碳酸盐岩的地球化学特征相近。结合微量元素和同位素地球化学分析,兰坪盆地的Sr、Cu、Pb和Zn等成矿元素主要来源于热卤水对地层的淋滤和萃取,成矿元素S主要为沉积地层中的硫酸盐热化学还原的产物。A large amount of gypsum occur in the most of metal deposits in the Lanping Basin.In order to explore the relationship between gypsum salt bodies and metal mineralization,trace elemental and isotopic analysis were carried out.The results showed thatΣREE,δEu(0.87)andδCe(0.95),^(87)Sr/^(86)Sr(0.708629~0.710189),δ^(34)S_(V-CDT)(9.6‰~11.9‰)of layered black gypsum developed in Yunlong Formation were similar to the regional geochemical characteristics of Yunlong Formation.TheΣREE,δEu(0.65)andδCe(0.85),^(87)Sr/^(86)Sr(0.707695~0.708127),δ^(34)S_(V-CDT)(12.6‰~15.4‰)of mushroom and fingerlike gypsum developed in Yunlong Formation were similar to the carbonate rocks of Late Triassic Sanhedong Formation.Combined with trace element and isotope geochemistry,the mineralizing elements such as Sr,Cu,Pb and Zn in the Lanping Basin are mainly derived from the leaching and extraction of the strata by hot brine.The mineralizing element S is mainly the product of thermochemical reduction of sulfate in the strata.

关 键 词：石膏 地球化学特征 滇西 兰坪盆地 

分 类 号：P597[天文地球—地球化学]