本文将参加年度优秀论文评选,如果您觉得这篇文章很好,请投下您宝贵的一票,谢谢! 支持(0)   不支持(0)

粤西河台金矿田糜棱岩XRD特征及其地质意义
投稿时间:2021-04-11  修订日期:2021-08-03  点此下载全文
引用本文:师爽,龚朝阳,焦骞骞,许德如,张胜印,常华诚,胡彬.2021.粤西河台金矿田糜棱岩XRD特征及其地质意义[J].地质论评,67(5):67060006,[DOI]:.
SHI Shuang,GONG Chaoyang,JIAO Qianqian,XU Deru,ZHANG Shengyin,CHANG Huacheng,HU Bin.2021.The XRD characteristics of mylonite in the Hetai gold orefield,western Guangdong,and its geological implication[J].Geological Review,67(5):67060006.
DOI:10.16509/j.georeview.2021.09.016
摘要点击次数: 500
全文下载次数: 372
作者单位E-mail
师爽 昆明理工大学国土资源工程学院昆明650093 373007131@qq.com 
龚朝阳 广东河台金矿广东肇庆526600  
焦骞骞 昆明理工大学国土资源工程学院昆明650093 289284567@qq.com 
许德如 东华理工大学核资源与环境国家重点实验室南昌330013  
张胜印 昆明理工大学国土资源工程学院昆明650093  
常华诚 昆明理工大学国土资源工程学院昆明650093  
胡彬 中国电建集团昆明勘测设计研究院有限公司昆明650051  
基金项目:本文为国家自然科学基金青年资助项目(编号:41902086)和国家自然科学基金项目重点资助项目(编号:41930428)的成果
中文摘要:粤西河台金矿田位于钦州湾—杭州湾(钦—杭)结合带南段的云开地区,是典型的受韧性剪切带控制的金矿。然而,对于剪切带中有利于金成矿的地质环境及其成矿过程仍然存在争议。本文在对河台矿区高村矿床进行详细野外地质调查的基础上,通过X射线衍射(XRD)对含金剪切带中各类糜棱岩系列岩石进行系统研究,建立应力变化—成分变异的对比序列,从而进一步揭示剪切变形与金矿化的关系。结果显示,剪切带中白(绢)云母的含量在9%~40%,并且在初糜棱岩、无矿糜棱岩、含矿糜棱岩、无矿超糜棱岩、含矿超糜棱岩中呈现出逐渐递增的趋势。白(绢)云母主要为2M1型,b0值在 0.55505~0.99002 nm之间,初糜棱岩<无矿糜棱岩< 无矿超糜棱岩,分别指示低压、中压和高压环境。可见,从初糜棱岩到超糜棱岩,随着变形强度的增加,热液活动也随之增强,从而新生成了大量白(绢)云母。然而,在含矿的糜棱岩和超糜棱岩中还存在一些低压白云母,推测其可能是在后期脆性裂隙中由于流体活动所新形成的。因此,成矿可能经历了两个阶段,即早期的韧性剪切变形阶段导致金的初步富集,后期叠加的脆性破裂阶段形成具有工业品位的矿体。另外,无矿超糜棱岩的石英含量(29.8%)明显低于糜棱岩(44.2%),推测在形成石英脉型矿体过程中,部分热液可能来自于其围岩超糜棱岩。因此,相对于初糜棱岩和糜棱岩,超糜棱岩中更有利于金矿的形成。
中文关键词:糜棱岩矿物含量  白云母b0值  含金剪切带  广东云开地区
 
The XRD characteristics of mylonite in the Hetai gold orefield,western Guangdong,and its geological implication
NameInstitution
SHI ShuangCollege of Land and Resources Engineering,Kunming University of Science and Technology,Kunming,650093
GONG ChaoyangGuangdong Hetai Gold Mine,Zhaoqing,Guangdong,526600
JIAO QianqianCollege of Land and Resources Engineering,Kunming University of Science and Technology,Kunming,650093
XU DeruState Key Laboratory of Nuclear Resources and Environment,Donghua University of Technology,Nanchang,330013
ZHANG ShengyinCollege of Land and Resources Engineering,Kunming University of Science and Technology,Kunming,650093
CHANG HuachengCollege of Land and Resources Engineering,Kunming University of Science and Technology,Kunming,650093
HU BinPower China Kunming Survey,Design and Research Institute Co.Ltd,Kunming,650051
Abstract:The Hetai gold orefield of Guangdong Province,located in the Yunkai area of southern segment of the Qinzhou Bay—Hangzhou Bay Juncture Orogenic Belt (QHJB),is occurred in shear zones. However,the favorable geological conditions and gold mineralization process in the shear zones are in controversy.Methods:Based on the detailed field geological investigation on the Gaocun gold deposit of the Hetai goldfield,we carried out X- ray diffraction (XRD) to study the characteristics of mylonitic sequence in the auriferous shear zones,establish contrast sequence of stresses variety with petrographic composition,and further reveal the ore genesis with shear deformation.Results:The muscovite content ranging from 9% to 40% in the shear zones,progressively increase from protomylonite,via barren and auriferous mylonite,to barren and auriferous ultramylonite.The muscovite in the shear zones was classified as 2M1 type that b0 values range from 5.5505 to 9.9002,and increase from protomylonite,via mylonite,to ultramylonite mylonite,corresponding to low-,medium-,and high-pressure.Therefore,it is deduded that the ore-forming fluids were intensified with the rock deformation extent,resulted in abundant neogenic muscovite or sericite from protomylonite to ultramylonite. However,the auriferous mylonite and ultramylonite present some low-pressure muscovite which is likely associated with the ore-forming fluids in the brittle fissures overprinted the shear zones. Conclusions:It indicates that the mineralization likely experienced two stages: minor sulfides occurred during ductile shearing stage,and economic Au precipitated in brittle fracture stage.Moreover,the quartz content in barren ultramylonite (29.8%) apparently less than mylonite (44.2%) suggests that some ore-forming fluids for the auriferous quartz vein-type ores were likely derived from the ultramylonite as wall rocks.Therefore,the Au mineralization is preferential in ultramylonite to protomylonite and mylonite in the shear zones.
keywords:mineral content of mylonite  muscovite b0 value  auriferous shear zones  Hetai gold depsoit  Yunkai area,Guangdong
查看全文  查看/发表评论  下载PDF阅读器
WeChat
s