| 邓丹莉.云南大坪金矿床流体包裹体研究及其意义[J].地质与勘探,2016,52(5):865-873 |
| 云南大坪金矿床流体包裹体研究及其意义 |
| A study of fluid inclusions from the Daping gold deposit of Yunnan and implications |
| 投稿时间：2016-03-15 修订日期：2016-06-23 |
| DOI： |
| 中文关键词: 成矿流体 包裹体 不混溶 大坪金矿床 |
| 英文关键词: ore-forming fluids,inclusions,immiscible fluids,Daping gold deposit, Yunnan Province |
| 基金项目:国家自然科学基金项目“甘肃干沙河稀土矿床碱性岩浆-流体演化过程研究”(批准号：41372094)资助 |
|
| 摘要点击次数: 2362 |
| 全文下载次数: 95 |
| 中文摘要: |
| 云南大坪金矿床是产于闪长岩中的石英脉型金矿床，矿体形态呈脉状，明显受断裂构造控制。成矿阶段可分为：早期成矿阶段(白钨矿石英脉)、主成矿阶段(硫化物石英脉)和晚成矿阶段(碳酸盐石英脉)。石英脉中的流体包裹体分为H2O包裹体、CO2包裹体、CO2-H2O包裹体，以富含CO2-H2O包裹体为特征。CO2-H2O包裹体的完全均一温度为283.1~382.0℃，盐度为4.44%~11.33%，计算的均一压力为151.2~261.5MPa，相应的成矿深度为10.272~12.649km，显示出该矿的成矿流体是一种富含CO2 的高压、中高温、中低盐度的H2O-NaCl-CO2的流体。加热时，富H2O 相的CO2-H2O 包裹体完全均一到H2O相，富CO2相的CO2-H2O包裹体完全均一到CO2相，而且二者的完全均一温度和压力一致，说明流体发生了不混溶作用，CO2 的溶离使成矿流体的pH 值升高，氧逸度fO2降低，从而导致Au溶解度的降低，并造成金沉淀成矿。大坪金矿床属于深成中高温热液石英脉型金矿床。 |
| 英文摘要: |
| The Daping gold deposit is of quartz vein type, which is hosted by diorite. Its ore bodies show a form of vein, obviously controlled by faults. Mineralization epochs of this deposit can be divided into three stages: the early stage (scheelite-bearing quartz vein )，the major stage (massive polymetallic sulphide in auriferous quartz vein) and the 1ate stage(carbonate-quartz).The fluid inclusions in quartz are divided into three categories: H2O inclusions,CO2 inclusions and CO2-H2O inclusions, among which the CO2-H2O inclusion is the main type. The ore-forming temperature was 283.1~382.0℃ and the salinity of the CO2-H2O inclusion was 4.44%~11.33%, the ore-forming pressure was in the range of 151.2~261.5MPa with corresponding metallogenic depths of about 10.272~12.649 km. The fluid inclusion characteristics indicate that the ore-forming fluid of the Daping mine is a H2O-NaCl-CO2 system of middle-high temperature with high-CO2 content and low to moderate salinity. When heated, the H2O-rich CO2-H2O inclusions were homogenized into H2O phase, and the CO2-rich CO2-H2O inclusions were homogenized into the CO2 phase. Moreover, they have the same homogenization temperature and pressure. When the immiscibility effect of the fluid occurred, a large amount of CO2 overflowed, the fugacity of O2 decreased, and pH increased. It led to the reduction of the solubility of gold in ore-forming hydrothermal fluid to the rapid precipitation of gold, and to the formation of deposits. The Daping gold deposit belongs to the middle-high temperature and high pressure deposits. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
