| 新疆京希-伊尔曼德金矿床矿化类型热液蚀变及流体包裹体证据 |
| 点此下载全文 |
| 引用本文：.2002.Gold Mneralization Styles of JingxL Yelmend Deposit : Evidence from Hydrothermal Alteration and Fluid Inclusion Data[J].Mineral Deposits,21(1):58~64 |
| Hits: 2635 |
| Download times: 2569 |
|
| 基金项目:中澳合作项目“中国新疆吐拉苏地区金矿勘察”和中国科学院知识创新项目r KZCX2-101) |
|
| 中文摘要:京希-伊尔曼德金矿床位于新疆伊宁县北部。金矿(化)体赋存于下石炭统大哈拉军山组下部粗碎屑岩中同时受控于断裂构造和岩眭。该矿床形成于浅成低温环境的高硫化体系中。初始强酸胜的含金热液流体在沿断裂构造向上迁移时，与围岩发生水-岩反应形成由内向外的物理化学梯度变化，表现为以硅化(发育酸胜淋滤形成的多孔状石英构造)、高级泥化和泥化构成蚀变分带。迪开石+高岭石+多孔状．硅化石英等热液蚀变矿物构成高级泥化主蚀变。金主要沉淀富集于硅化带和高级泥化带。蚀变矿物组合及流体包裹体资料确定的成矿流体胜质为：酸眭(pH早期为2~3，晚期为3~5）、低盐度[w( NaCI)eq<5%]及低温（成矿温度为180~ 270℃)。 |
| 中文关键词:矿化类型， 热液蚀变， 高硫化，流体包裹体， 新疆 |
| |
| Gold Mneralization Styles of JingxL Yelmend Deposit : Evidence from Hydrothermal Alteration and Fluid Inclusion Data |
|
|
| Abstract:Hydrothermal alteration and fluid inclusion data of the Jinxi- Yelmend gold deposit show that the ore-fluid was characterized by low- pH (from early stage 2~3 to late stage of 3 ~ 5) , low-salinities [ore-stage w( Na0) eq < 5 .3 ] , and relatively low te mperature ( 180~270℃) . These features, along with the dominated alteration mineral assemblage ( dickite + kaolinite + silica) indicate that the mineralization style of the Jinxi Yelmend gold deposit might have been subjected to high sulfidation mineralization . Three styles offluid evolutions are recognized: i) when initial acidic ( pH < 3) ore fluid was buffered by reaction of fluid/ neutral limestone as it ascended along steey dipping faults , its pH values slightly increased ; ii) pH value increased to 3 ~ 5 when ore fluid reached high permeable epiclastic rocks ( conglomerate and conglomeratic sandstone) and rapidly reacted with country rocks, articularly with the assistance of in-charging meteoric water. During this stage , the composition, temperature and pH values were changed and the gradients were generated. High concentrated residual Sioz and most acidic (low pH) fluids were retained in the central part of the fluid flow zone, where there occurred vuggy quartz ( acidic leaching) and dickite , while the marginal parts had relatively higher pH values and developed inter mediate- argillic alteration. With the decreasing of te mperature and increasing of oxidation condition of the ore fluids , the alteration zonation was formed and gold was precipitated and , iii) late-stage barite contained low-salinity [w( Na0) eq < 1 .5 %] and low- temperature ( 90~110℃) fluid inclusions. High-sulfidation mineralization at Jinxi- Yelmend is a newly recognized mineralization style in northwest Tianshan Mountains. This discovery indicates increased prospecting potential for porphyry- related copper and Au syste m in Northwest Tianshan belt of China, where there exists great potential for additional discoveries . |
| keywords:High-sulfidation alteration mineralogy, fluid inclusion, gold deposit , Xinjiang |
| View Full Text View/Add Comment Download reader |
