云南个旧锡矿的玄武岩成矿

个旧锡矿产于个旧东区，是一个以锡铜为主的超大型多金属矿床，具有火山沉积成矿的某些特征。因遭受燕山期花岗岩的叠加改造，区内个旧组卡房段中玄武岩遭受强烈的变质，它又具有花岗岩热液成矿的特征。区内玄武岩的地质地球化学特征表明，印支期玄武岩中的Sn、Cu、Pb、Zn、Ag和Au的质量分数大多数高于世界玄武岩平均值的若干倍；矿石硫化物的硫同位素δ³⁴S为-1.5‰~4.0‰，平均+0.207‰，在幔源硫附近；铅同位素模式年龄分为两组：第一组为180~240 Ma，反映了印支期的火山沉积成矿作用；第二组为80~140 Ma，反映了燕山期花岗岩的叠加改造成矿作用。区内印支期玄武岩为个旧锡铜多金属矿床的形成提供了主要的成矿物质，与成矿有直接联系。

Mineralizations in Basalts of the Gejiu Tin Deposit in Yunnan Province

Located in eastern Gejiu area, the Gejiu tin ore deposit is a super large polymetallic deposit dominated by tin and copper mineralization and featured by characteristics of the volcano sedimentary ore deposits. Reworked by granites of the Yanshanian epoch, the basalts of the Gejiu Formation underwent intense metamorphism. The authors deal with the geological and geochemical features of the basalt and related mineralization in the area. The results of the research are: The contents of Sn, Cu, Pb, Zn, Ag and Au in the Indosinian basalt in the area are higher than those in average basalt of the world;The sulfur isotopes of sulfides in the deposits are between -1.5‰ and 4.0‰, similar to those of the mantle; Model ages of lead isotopes of the ores can be divided into two groups: The first group ranges from 180 Ma to 240 Ma, which represents basic volcano sedimentary mineralization of the Indosinian epoch, while the second group ranges from 80 Ma to 140 Ma representing the superimposed mineralization of the Yanshanian granite. It’s believed that the Indosinian basalt provided the ore forming materials for the ore deposit and was directly related to the mineralization in the area.