摘要
湖南石门砷-(金)矿床属古热泉成因,具有典型的三层结构模式,矿体呈筒状;矿床中硅质体属热泉沉积的硅华;矿石中微量元素同该区现代热泉体系沉积物的类似;成矿溶液富Na^+,Ca^(2+),Cl^-,HCO_3^-和SO_4^(2-),也与该区现代热泉水成分相似。泉水的氢、氧、氩、氦同位素研究表明,成矿溶液中水主要为大气降水。提出了热泉型砷-(金)矿床的成矿模式:下渗的大气降水被深部热流体加热,在地层中循环运移时,淬取地层中成矿元素和矿化剂,沿断裂上涌,由于减压沸腾作用以及物化条件改变,沉淀出砷及少量的金、锑等成矿元素。
The Shimen As-(Au) deposit in Hunan Province, characterized by a pipe-shaped ore body and a typical structural model of three layers, is believed to be of hot spring origin. Silicalites in the ore body are most probably, silica sinters deposited from hot spring waters. Trace elements in ores are similar to those in sediments from modern hot springs, and the components of ore-forming fluids enriched in Na+, Ca2+, Cl-, HCO4- and SO42- are also similar to those of modern spring waters in the area. O,H, Ar and He isotope studies of hot spring waters show that they came dominantly from meteoric water and, by analogy, the ore forming-fluids may be alsd mainly from meteoric water. A minerogenetic model of As-(Au) deposits of hot spring type is proposed in the paper: circulating', migrating in strata and being heated by the deep thermal flow system; the percolating meteoric water may scavenge ore elements and mineralizing agents from the strata, resulting in ore-forming fluid. As this fluid rise up along faults, boiling and precipitation of such ore elements as As and minor Au and Sb would be brought about owing to abrupt chenges in physiochemical conditions.
出处
《地质论评》
CAS
CSCD
北大核心
1994年第5期429-435,共7页
Geological Review
关键词
砷矿床
成矿模式
金矿床
古热泉
hot spring type, As deposit, minerogenetic model, Shimen Hunan
