Sulphur and metal sources of polymetallic vein-type, sedimentary exhalative-type and Mississippi Valley-type Zn–Pb deposits along the southeast margin of the Yangtze Block
Sulphur and metal sources of polymetallic vein-type, sedimentary exhalative-type and Mississippi Valley-type Zn–Pb deposits along the southeast margin of the Yangtze Block
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DOI：
10.1016/j.oregeorev.2022.104957
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发表时间：
2022-05
影响因子：
3.3
通讯作者：
Zhengbing Zhou;H. Wen;Jeffrey de Fourestier;Chaojian Qin;Ling Liu
中科院分区：
文献类型：
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作者：
Zhengbing Zhou;H. Wen;Jeffrey de Fourestier;Chaojian Qin;Ling Liu
扬子地块东南缘已发现多金属脉型、沉积喷流型（SEDEX）和密西西比河谷型（MVT）锌铅矿床三种类型的锌铅矿床。缺乏对这些矿床的硫和金属来源的系统比较研究，这极大地限制了对成矿模型和地质勘探的理解。因此，为了揭示铅锌矿床的硫、铅来源，本研究对这三类锌铅矿床中的闪锌矿微量元素和硫化物的硫铅同位素组成进行了研究。我们发现，在脉型、SEDEX和MVT锌铅矿床中，（1）硫分别来源于与广西造山运动有关的花岗质岩浆作用、早寒武世层结海水和原生水； （2）铅同位素变化表明，脉状矿床成矿金属主要来源于花岗质热液，SEDEX矿床主要来源于基岩，MVT矿床主要来源于早寒武世沉积岩。南华裂谷导致同生锌铅矿化，广西造山运动导致深部岩浆热液脉成矿和浅地壳水平MVT矿化。
Three types of zinc-lead deposits, including polymetallic vein-type, sedimentary-exhalative (SEDEX), and Mississippi valley-type (MVT) Zn–Pb deposits, have been discovered along the southeast margin of the Yangtze Block. A systematically comparative study on the sulphur and metal sources for these deposits, is absent, which significantly limits the understanding of the metallogenic model and geological exploration. Thus, in order to reveal the S and Pb sources of Pb–Zn deposits, an investigation of trace elements of sphalerite and of S–Pb isotopic compositions of sulphides in these three types of Zn–Pb deposits was conducted in this study. We found that, in the vein-type, SEDEX, and MVT Zn–Pb deposits, (1) the sulphur was derived respectively from granitic magmatism related to the Guangxi Orogeny, early Cambrian stratified seawater and connate water; (2) the lead isotope variation indicates that the ore-forming metals were mainly derived from the granitic hydrothermal fluids for vein-type deposits, from basement rocks for SEDEX deposits, and mainly from early Cambrian sedimentary rocks for MVT mineralization. The Nanhua rifting lead to the syngenetic Zn-Pb mineralization, while the Guangxi Orogeny resulted in magmatic-hydrothermal vein mineralization at depth and in MVT mineralization at the shallow crustal levels.