摘要
广西大厂锡石硫化物矿床是在泥盆系同生沉积的基础上,经燕山晚期花岗岩热液的改造和叠加形成的。成矿模拟实验结果表明:矿床中同生沉积的黄铁矿在热流的作用下,一方面相变为磁黄铁矿,另一方面作为碱性的地球化学垒,促使晚期含锡热液卸载、沉淀;酸碱度的变化是控制含矿溶液在层状硫化物矿体中叠加矿化的主要因素。
The geological survey and geochemical researches show that Dachangtin deposits are controlled by Devonian tin-bearing stratiform sulfidesfollowed by transformation and superimposition of tin-bearing hydrother-mal solutions derived from Late Yenshanian granites. Simulation experi-ments reveal that, under the impact of heat current some synsedimentarypyrites carried from the straitiform sulfides can, on the one hand. betransformed into pyrrhotites and on the other hand, be acted as analkaline geochemical barrier. or a neutralizer, resulting in the precipita-tion of cassiterites from acid tin-bearing solutions.
关键词
锡矿
成矿溶液
模拟实验
叠加型
tin ore deposit
strata-bound ore deposit
ore-forming solution
simulation expetiment
Guangxi
Dachang
