| 西秦岭大店沟金矿成矿流体演化及矿床成因 |
| |
| 引用本文： | 缪广,董国臣,屈海浪,刘舒飞,艾忠林,史鹏亮,曹雪峰.西秦岭大店沟金矿成矿流体演化及矿床成因[J].现代地质,2021,35(6):1565-1575. |
| |
| 作者姓名： | 缪广 董国臣 屈海浪 刘舒飞 艾忠林 史鹏亮 曹雪峰 |
| |
| 作者单位： | 1.中国地质大学(北京) 地球科学与资源学院,北京 1000832.北京金有地质勘查有限责任公司,北京 1000113.中国黄金集团有限公司,北京 1000114.甘肃中金黄金矿业有限责任公司,甘肃 陇南 742400 |
| |
| 基金项目： | 中国黄金集团有限公司地质科研专项基金项目(WKY201603) |
| |
| 摘 要： | 大店沟金矿是西秦岭成矿带近年来新发现的中型金矿床,金矿体赋存在下古生界丹凤群木其滩组绢云绿泥石英片岩中,叠加在北东东向脆韧性剪切带中的脆性构造为成矿结构面。在总结控矿地质特征的基础上,通过开展系统的流体包裹体、稳定同位素地球化学研究及成矿流体演化、矿床成因探讨,认为成矿期共分半自形黄铁矿、它形粒状黄铁矿、石英多金属硫化物和碳酸盐-黄铁矿4个成矿阶段,其中它形黄铁矿阶段和石英多金属硫化物阶段为最主要成矿阶段。流体包裹体类型以水溶液包裹体、CO2三相包裹体和纯CO2包裹体为主,成矿温度集中在120~256 ℃之间,成矿流体盐度为4.03%~15.27%。H-O同位素研究显示成矿热液主要为变质水混合大气降水,S同位素组成特征表明成矿物质来自深源;流体不混溶和沸腾作用是金沉淀的主要机制,矿床成因类型为造山型金矿。通过成矿结构面舒缓波状特征规律总结,判断成矿流体沿成矿结构面自南西深部向北东浅部运移、沉淀,形成分段富集矿化。
|
| 关 键 词： | 西秦岭 大店沟金矿 流体演化 造山型金矿 成矿结构面 |
| 收稿时间： | 2021-06-25 |
| 修稿时间： | 2021-08-28 |
Ore-forming Fluid Evolution and Genesis of the Dadiangou Gold Deposit in the Western Qinling Metallogenic Belt |
| |
| MIAO Guang,DONG Guochen,QU Hailang,LIU Shufei,AI Zhonglin,SHI Pengliang,CAO Xuefeng.Ore-forming Fluid Evolution and Genesis of the Dadiangou Gold Deposit in the Western Qinling Metallogenic Belt[J].Geoscience——Journal of Graduate School,China University of Geosciences,2021,35(6):1565-1575. |
| |
| Authors: | MIAO Guang DONG Guochen QU Hailang LIU Shufei AI Zhonglin SHI Pengliang CAO Xuefeng |
| |
| Institution: | 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China2. Beijing Jinyou Geological Exploration Co.,Ltd., Beijing 100011, China3. China National Gold Group Co.,Ltd., Beijing 100011, China4. Gansu Zhongjin Gold Mining Co.,Ltd., Longnan, Gansu 742400, China |
| |
| Abstract: | Located in the Western Qinling Metallogenic belt, the Dadiangou gold deposit is a newly discovered medium-sized gold deposit. The orebody occurs in the sericite-chlorite-quartz schist of Lower Paleozoic Danfeng Group (Muqitan Formation). The brittle structures (superimposed by NE-trending brittle-ductile shear zone) is the ore-forming structure. Based on geological characteristics, this study systematically studies the fluid inclusions, stable isotope geochemistry, ore-fluid evolution, and metallogenesis. The ore formation can be divided into four stages, among which the heteromorphic granular pyrite and the quartz-polymetallic sulfide stages are the main ore stages. Fluid inclusions include mainly aqueous, CO2-bearing three phase and pure CO2 aqueous types. The homogenization temperature of the ore-forming fluids was mainly 120 to 256 ℃, and the salinity is of 4.03% to 15.27% NaCl eqv. The H-O isotopic data show that the ore-forming fluid was mainly derived from the meteoric water mixed with metamorphic water. Characteristics of S isotopes indicate that the ore-forming materials were mainly deep sourced. Strong water-rock reaction and fluid boiling is the main gold precipitation mechanism. In summary, the Dadiangou is best classified as orogenic gold type. By summarizing the characteristics of relief wave of the ore-forming structural plane, we suggest that the ore-forming fluid ascended and precipitated from the southwest to the northeast, forming the segmented mineralization. |
| |
| Keywords: | Western Qinling Dadiangou gold deposit ore-fluid evolution orogenic gold deposit ore-forming structural plane |
|
| 点击此处可从《现代地质》浏览原始摘要信息 |
| 点击此处可从《现代地质》下载免费的PDF全文 |
|
