- 责任者：Liu Xiaofei (School of Earth Sciences and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Yuan Shunda
- 刊名：Acta Petrologica Sinica
- 出版年：2013
- 卷期：29(12)
- 关键词：锡矿 ; tin ores ; 铋矿 ; bismuth ores ; 流体包裹体 ; fluid inclusions ; 湖南 ; Hunan Province
- 页码：p.4245-4260
- 图表：13 illus., 1 table, 79 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
The Jinchuantang deposit is a large-sized skarn-type tin-bismuth polymetallic deposit in the Dongpo ore field, therefore the evolution of ore-forming fluid and the mechanism of polymetallic mineralization of this deposit are crucial to understand the evolution of granitic magmatism and related metallogenesis in this region. But little has been known about the evolution of ore-forming fluid and physicochemical conditions of ore formation in the Jinchuantang deposit so far. Based on detailed field investigation of the Jinchuantang tin-bismuth deposit, we have carried out systematic microscope observation, detailed micro-thermometric measurement of the fluid inclusions, and Laser Raman spectroscopic analysis, and preliminarily discussed the geological characteristics and fluid evolution of the deposit. The following conclusions have been obtained： （1） The mineralizations of the Jinchuantang deposit can be divided into five stages, i.e., the skarn stage, retrograde stage, greisen stage, cassiterite-sulfide stage, and barren quartz-carbonate stage; （2） The composition of the ore-forming fluid is mainly H2O, and there is a little CO2, CH4, SO2 in the gas phase, and the daughter mineral component is mainly NaCl, containing little KCl, and therefore we consider that the ore-forming fluid belongs to system of H2O-NaCl（KCl）-CO2（CH4）; （3） The homogenization temperatures of the fluid inclusions range from 174℃ to 〉550℃ （mainly above 550℃） and the salinities are between 5.41% and 15.27% NaCleqv in the skarn stage; the homogenization temperatures of the fluid inclusions range from 143℃ to 〉550℃ （concentrated in 230~300℃） and the salinities range from 1.22% to 37.41% NaCleqv in the retrograde stage; in greisen stage, the homogenization temperatures range from 220℃ to 500℃ （mainly 240~350℃） and the salinities are 3.0%~14.3% NaCleqv; in cassiterite-sulfide stage the homogenization temperatures range from 170℃ to 368℃ （concerntrated in 220~270℃） and the salinities are 0.35%~7.86% NaCleqv. In general, the ore-forming fluid has a tendency to become low temperature and low salinity from the early to late stage, the density of the fluid is about 0.65~1.0g/cm3, the pressure is 120~200MPa, and the corresponding metallogenic depth is about 4~7km; （4） The ore-forming fluid was dominantly magmatic origin, with the progressive mixing with cooler meteoric water in the process of fluid evolution, and the fluid boiling induced by pressure decrease and the mixing of high and low temperature fluids maybe the main mechanism for cassiterite precipitation.