摘要
大厂锡石-硫化物矿田的成矿特征显示出围岩的地球化学作用,花岗岩侵入在厚大的富有机质地层中而处于低f_(O_2)环境,锡以二价状态不能大量进入造岩矿物才富集于岩浆热液中,至弱碱性围岩里才析出形成锡石-硫化物矿床。围岩介质不但供给了一部分成矿物质,也影响到矿物组合、同位素组成、气液包裹体成分、杂质元素等规律性变化。
Our metallogenic studies of the Dachang ore field show that the country-rock media have great influence on the process of mineralization. They can not only contribute part of the ore-forming material, but also have influence on the geochemical evolution of granitic magma and ore fluids. The Dachang ore field can be taken as a typical example to show the influence of country-rock media on mineralization. Geological field investigations indicate that where granites intruded weakly alkalic country rocks (e.g. middle Devenian limestones and silicorites of platform facies in the Dachang), instead of carbonaceous shales of reducing basin facies, Sn would be able to enter rock-forming minerals in large quantities to form cassiterite-sulfide ore deposits of commercial value. So it may be concluded that the process of magmatic differentiation-evolution, mineralization and tectonic settings of ore deposits are, more or less, controlled by their country-rock media.
出处
《地球化学》
CAS
1987年第2期123-131,共9页
Geochimica
