CAJ | 학술논문

越南东北部佐田（Cho Dien）铅锌矿床分布在北太省（Bac thai）西部则屯西北，属于华南褶皱系越北隆起区。为了探讨该-矿床的成矿物质来源和成矿机制，对该矿床的矿石样品进行了S、Pb同位素组成分析。结果表明，5件样品的11种金属硫化物（闪锌矿、磁黄铁矿、方铅矿）的δ34S值为4.1‰~6.8‰，平均值为5.51‰，极差为2.7‰，显示S同位素组成比较稳定，经计算热液的δ34S值约为7‰。11种金属硫化物样品的206Pb/204Pb、207Pb/204Pb和208Pb/204Pb变化范围分别为18.451~18.682、15.685~15.878、38.909~39.636，平均值分别为18.59855、15.78227和39.30773，矿石矿物μ值为9.36~9.98，平均值为9.80，ω值为39.04~42.63，平均值为40.79。Th/U值为3.92~4.13，平均值为4.03。结果表明，佐田铅锌矿床的硫主要来自沉积围岩及三叠纪的Phia Bioc杂岩，矿石铅主要来自上地壳物质，也有地幔物质的加入。综合上述成果及已有数据认为，佐田铅锌矿是在特提斯成矿域早三叠世碰撞环境下形成的，板块碰撞过程中形成的Phia Bioc花岗岩体为矿床的形成提供了一定的物质基础，属热液型矿床。
월남동북부좌전（Cho Dien）연자광상분포재북태성（Bac thai）서부칙둔서북，속우화남습추계월북륭기구。위료탐토해-광상적성광물질래원화성광궤제，대해광상적광석양품진행료S、Pb동위소조성분석。결과표명，5건양품적11충금속류화물（섬자광、자황철광、방연광）적δ34S치위4.1‰~6.8‰，평균치위5.51‰，겁차위2.7‰，현시S동위소조성비교은정，경계산열액적δ34S치약위7‰。11충금속류화물양품적206Pb/204Pb、207Pb/204Pb화208Pb/204Pb변화범위분별위18.451~18.682、15.685~15.878、38.909~39.636，평균치분별위18.59855、15.78227화39.30773，광석광물μ치위9.36~9.98，평균치위9.80，ω치위39.04~42.63，평균치위40.79。Th/U치위3.92~4.13，평균치위4.03。결과표명，좌전연자광상적류주요래자침적위암급삼첩기적Phia Bioc잡암，광석연주요래자상지각물질，야유지만물질적가입。종합상술성과급이유수거인위，좌전연자광시재특제사성광역조삼첩세팽당배경하형성적，판괴팽당과정중형성적Phia Bioc화강암체위광상적형성제공료일정적물질기출，속열액형광상。
The Cho Dien Pb-Zn deposit in northwest Cho Don of Bac thai Province, northeast Vietnam, is located in the north-Vietnam uplift of the South China fold system. In order to explore the ore-forming material sources of the Cho Dien Pb-Zn deposit-and acquire an overall understanding of the metallogenic mechanism, the authors collected ore samples from the orebody to analyze the sulfur and lead isotope composition. The results achieved show thatδ34S values of eleven metal sulfides (sphalerite, galena, pyrrho?tite) vary from 4.1‰to 6.8‰, with an average value of 5.51‰and the range of 2.7‰, indicating that the sulfur isotope composition is stable. Through the calculation, δ34S value of the hydrothermal solution is about 7‰, showing that the source of sulfur was mainly strata sulfur, with some mixture of magmatic sulfur. 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios of the eleven metal sulfides (sphalerite, galena, pyrrhotite) vary in the range of 18.451~18.682, 15.685~15.878, 38.909~39.636, with the average value being 18.59855, 15.78227 and 39.30773, respectively. Calculations also show that the sulfides have a relatively high μ values (9.36~9.98), ω values(39.04~42.63) and Th/U (3.92~4.13), with the average value being 9.8, 40.79 and 4.03, respectively. These lead compositions indi?cate that the ore-forming materials not only had features of the upper crust but also had characteristics of the mantle. The metal sul?fide isotope compositions show that the sulfur of the Cho Dien Pb-Zn deposit was mainly from sedimentary rock, with some from the Phia Bioc pluton of Triassic, while the lead of the Cho Dien Pb-Zn deposit was mainly from the upper crust, with some from--the Phia Bioc pluton. The present data, combined with previously published results, indicate that the ore deposit was formed due to collision between Indochina and South China Blocks in the Early Triassic period. The Phia Bioc pluton resulted from the collision process and it provided the ore-forming material for the Cho Dien Pb-Zn deposit, which genetically belongs to hydrothermal de?-posit.