摘要
对类似于贵州南部微细粒浸染型金矿床的流体性质进行的研究,为其矿床成因、富集规律提供了重要依据。借助于包裹体分析,可以研究成矿流体的形成温度、压力、成分,流体运移的pH、Eh值,从而分析出成矿物质活化、运移、富集的条件和形式,预测矿体展布,指导找矿。本...
Abstract The disseminated gold deposits in Guizhou are mainly distributed in the Qianxinan and Sandan districts in southern Guizhou. The research in the present paper focuses on the studies of inclusions, temperatures and pressures for the formation of ore forming fluids, fluid compositions, pH and E h values during fluid migration, and the circumstances and modes of the mobilization, migration and concentration of the ore forming matter. The results of research of the inclusions indicate that the liquid inclusions are generally dominant, and the gas liquid ratios are commonly less than 10%. The inclusions are colourless and transparent, relatively small varying in size from 1 to 10 μm, and exhibit regular forms. The temperatures of the ore forming fluids range between 130℃ and 300℃, with an average of about 170℃. The ore forming solutions from the Sandan district are ascribed to the Ca Na SO 4 type, with higher salinity and density, whereas those from the Qianxinan district are assigned to the Na Ca Cl F type, with lower salinity and density. The ore forming fluids are characterized by lower oxygen fugacity and higher carbon dioxide fugacity, and being intermediate to weakly alkaline, indicating a reduction environment. The ore forming solutions consist of stratigraphic formation water and oil field water in addition to meteoric water. The gold as an ore forming element in the gold deposits was migrated in the form of the complexes [Au(HS) 2] - and [Au 2(HS) 2S] 2- .
出处
《沉积与特提斯地质》
CAS
CSCD
1998年第A01期109-120,共12页
Sedimentary Geology and Tethyan Geology