摘要
位于贵州赫章县境内的板板桥铅锌矿床是近年来新发现的一处中型矿床,累计探明铅锌矿石量超过1.5×10^9kg,Pb平均品位0.26%~10.32%,Zn平均品位0.81%~28.8%。目前,对该矿床的研究还很薄弱,特别是硫化物中稀散元素的富集特征尚不清晰,制约了对该矿床成因的深入认识以及稀散元素的综合利用。本文利用电感耦合等离子体质谱(ICP-MS),分析了该矿床主成矿阶段硫化物(闪锌矿、黄铁矿和方铅矿)中稀散元素的富集特征,并试图揭示其蕴含的地质意义。结果表明,稀散元素主要以类质同象形式富集在闪锌矿中,但稀散元素(尤其是Ge)很可能不是直接替代Zn进入闪锌矿晶格中,而是与Fe一起共同置换Zn进入闪锌矿晶格中,这代表了一种新的闪锌矿中稀散元素替代方式。另外,硫化物中稀散元素含量及相关参数表明,板板桥铅锌矿床的形成温度较低,属于后生低温热液矿床。综合已有的矿床地质、地球化学等资料,本文认为板板桥铅锌矿床是流体-构造耦合作用的产物,其成因属于以碳酸盐岩为容矿围岩的后生热液矿床,与川滇黔接壤铅锌矿集区内其它铅锌矿床成因一致。
The Banbanqiao Pb-Zn deposit is a newly discovered medium-sized deposit in Hezhang County, Guizhou Province in recent years, with over 1.5 million tons of proved Pb-Zn ores at Pb grades of 0.26%-10.32% and Zn grades of 0.81%-28.8%. At present, the research on this deposit is still very limited. Especially, the enrichment characteristics of dispersed elements in sulfides are not yet clear. This restricts the in-depth understanding of the genesis of this deposit and the comprehensive utilization of key resources of dispersed elements. In this paper, inductively coupled plasma mass spectrometry(ICP-MS) was used to analyze contents of dispersed elements in sulfides(i.e., sphalerite, pyrite and galena) formed in the main metallogenic stage of the Banbanqiao deposit, in order to study the enrichment characteristics of dispersed elements in sulfides and to reveal their geological significances. The results show that the dispersed elements are mainly concentrated in sphalerite in the form of homomorphism, though the disperse elements(especially Ge) could enter into the lattice of sphalerite in form of the Zn replacement by the dispersed elements coupled with Fe rather than the Zn replacement directly by dispersed elements. This represents a new way of dispersed elements replacing Zn in the lattice of sphalerite. In addition, the contents and related parameters of dispersed elements in sulfides indicate that the Banbanqiao Pb-Zn deposit was formed under relatively low temperature and belongs to the epigenetic low-temperature hydrothermal deposit. Based on the integration of existed data of geology and geochemistry of the deposit, it is believed that the Banbanqiao Pb-Zn deposit is a product of the fluid-structure coupling. It belongs to the carbonate-hosted epigenetic hydrothermal deposit with the similar ore genesis of those Pb-Zn deposits in the Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province.
作者
潘萍
常河
PAN Ping;CHANG He(School of Land Resources Engineering,Kunming University of Science and Technology,Kunming 650093,China;Geomatics Engineering Faculty,Kunming Metallurgy College,Kunming 650033,China)
出处
《矿物学报》
CAS
CSCD
北大核心
2020年第4期404-411,共8页
Acta Mineralogica Sinica
基金
国家自然科学基金项目(编号:41572060,U1812402)
云南省矿产资源预测评价工程实验室项目(2010)
云南省地质过程与矿产资源创新团队项目(2012)。
关键词
硫化物
稀散元素
富集特征
地质意义
板板桥铅锌矿床
Sulfides
dispersed elements
enrichment characteristics
geological significance
the Banbanqiao Pb-Zn deposit
