滇东北富乐厂铅锌矿床地球化学及找矿方向研究

发布时间：2019-02-28 17:02

【摘要】：富乐厂大型铅锌矿床位于我国西南川-滇-黔铅锌多金属成矿区南段,矿体呈似层状、透镜状赋存于中二叠统茅口组白云岩的层间破碎带中;该矿床Pb+Zn金属量大于100万吨,Pb+Zn平均品位大于15.6%;矿石中富含Cd,Se,Ge,Ga多种分散元素,特别是该闪锌矿中Cd的平均含量为16183ppm,是我国迄今发现含量最高的铅锌矿床之一。一个铅锌矿床同时伴生4种分散元素,且规模大,在世界铅锌矿床中也称为罕见。本次工作系统研究了硫化物中常量元素、微量元素、稳定同位素地球化学特征,主要取得以下成果和认识:1.该矿床闪锌矿中最大的特点是富含Cd元素,含量变化于0.347~2.19%之间,同时还含有少量Ge、As、Se、Sb等元素。在Fe-Zn含量变化图上,二者显示了较明显的负相关关系,表明闪锌矿中Fe可能主要替换Zn进入闪锌矿的晶格;相比闪锌矿,Cd在方铅矿中含量明显降低,说明Cd易于进入闪锌矿晶格;砷黝铜矿主要产于铅锌矿石内,其中锌含量普遍较高,据此特征将其定名为锌砷黝铜矿。2.闪锌矿中 Ga、In 平均含量为 Ga=2.23~684ppm;In=0.1~3.13ppm。对于同一件闪锌矿样品,浅色和深色闪锌矿之间的微量元素含量并没有明显的变化。方铅矿中微量元素含量普遍低于闪锌矿,但元素Bi含量比闪锌矿高一个数量级,显示了在方铅矿中富集的特征。3.在δ13C-δ18O上,所有数据均落在海相碳酸盐岩附近,反映流体中的CO2为碳酸盐岩的溶解作用。硫化物δ34S值主要集中于13‰~14‰。,据这此特征推测该矿床成矿流体中硫主要来自地层。区域结晶基底(昆阳群)和各时代沉积地层中碳酸盐岩及峨眉山玄武岩铅同位素组成投影到206Pb/~204Pb～~207Pb/~204Pb图中进行比较,可以看到该矿床Pb同位素主要集中于昆阳群Pb同位素组成内,少量样品落入峨眉山玄武岩或者盖层碳酸盐岩区域。说明该矿床成矿物质主要来源于昆阳群,具有多源特征。综合矿床地质和地球化学特征,该矿床具有会泽型铅锌矿床的成因,为受构造控制产于P_1m中上部蚀变白云岩中的块状铅锌矿床,因此,矿区东南段为主要找矿靶区。
[Abstract]:The large-scale lead-zinc deposit in the rich plant is located in the south section of the southwest Sichuan-Yunnan-Guizhou Pb-Zn-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Pb-Zn-Pb-Pb-Zn-Pb-Pb-Zn-Pb-Pb-Zn deposit in the middle Permian Maokou Formation. The Pb + Zn metal content of this deposit is more than 1 million tons, and the average grade of Pb + Zn is more than 15.6%. The average content of Cd, Se, Ge and Ga in ore is 16183 ppm, which is one of the most found Pb-Zn deposits in China to date. A lead-zinc bed is also associated with 4 dispersed elements and has a large scale and is also known as a rare in the world lead-zinc deposit. The geochemical characteristics of constant elements, trace elements and stable isotopes in the sulfide are studied in this work system, and the following results and understandings are mainly obtained:1. The biggest characteristic of sphalerite in this deposit is that it is rich in Cd, the content of which is 0.347-2.19%, and contains a few elements such as Ge, As, Se, Sb and so on. Compared with the sphalerite, the content of the Cd in the galena is obviously reduced, and the Cd is easy to enter the sphalerite crystal lattice; The arsenic-bearing copper ore is mainly found in the lead-zinc ore, in which the content of zinc is generally higher, and its name is zinc arsenite. The average content of Ga and In in sphalerite is Ga = 2.23-684 ppm; In = 0.1-3.13 ppm. There was no significant change in the content of trace elements between the light and dark sphalerite for the same sphalerite sample. The content of trace elements in galena is generally lower than that of sphalerite, but the content of element Bi is an order of magnitude higher than that of sphalerite. On the 13C-1818O, all the data falls in the vicinity of the marine carbonate, which reflects the dissolution of the CO2 in the fluid. The S-value of sulfide is mainly in the range of 13 to 14%. According to this feature, it is assumed that the sulfur in the ore-forming fluid is mainly from the formation. The Pb-isotopic composition of the Pb-isotope in the regional crystal substrate (Kunyang group) and the carbonate and Emeishan basalt lead-isotopic compositions in the sedimentary strata of the time is compared with that of 206Pb/ ~ 204Pb ~-207Pb/ ~ 204Pb. The Pb isotope of the deposit is mainly concentrated in the Pb isotope composition of the Quyang Group. A small amount of the sample falls into the carbonate region of the Emeishan basalt or caprock. It is indicated that the ore-forming minerals are mainly from the Kunyang group and have multi-source characteristics. The geological and geochemical characteristics of the comprehensive deposit, which have the origin of the Huize Pb-Zn deposit, are the massive lead-zinc deposit in the upper altered dolomite in the P _ 1 m, so that the southeast section of the mining area is the main prospecting target area.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.4

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