投稿时间：2020-08-18
修订日期：2021-04-22
网络发布日期：2021-07-12
中文摘要:西藏斯弄多银多金属矿床产于陆相林子宗群火山岩内，是冈底斯成矿带发现的首例浅成低温热液矿床。矿床具有热液脉型银铅锌矿体、隐爆角砾岩型矿体和独立银矿体“三位一体”的矿体组合形式。热液角砾岩作为矿区主要矿（化）体，目前尚未开展详细研究工作。文章以斯弄多矿区热液角砾岩为研究对象，通过钻孔岩芯编录和岩相学研究，总结了不同类型热液角砾岩特征，旨在探讨其成因及与成矿的关系。根据热液角砾岩产状、颜色、胶结物等特征，将矿区热液角砾岩分为气喷角砾岩、岩浆蒸汽角砾岩和构造热液角砾岩三类。岩浆蒸汽角砾岩产于隐爆角砾岩筒中，根据其产状、颜色、胶结物成分差异进一步分为A类角砾岩和B类角砾岩。A类角砾岩产于Ⅰ号富矿角砾岩筒，蚀变矿物以绢云母、蒙脱石、伊利石为主；B类角砾岩产于Ⅱ号贫矿角砾岩筒，蚀变矿物以白云母、赤铁矿、黄钾铁矾为主。研究认为，与成矿作用密切相关的热液角砾岩成岩成矿作用是同一地质过程不同阶段的产物，其含矿性主要由隐爆流体性质决定。大气降水和岩浆热液不同程度的混合作用和沸腾作用是角砾岩形成和矿质沉淀的主要原因。
Abstract:The Sinongduo Ag polymetallic deposit, the first epithermal deposit discovered in the Gangdise metallogenic belt, is hosted in the volcanic rocks of Linzizong Group. The deposit has a combination of hydrothermal vein-type silver-lead-zinc orebodies, cryptoexplosive breccia-type orebodies and independent silver orebodies. As one of the main mineralized bodies in the mining area, hydrothermal breccia has not been systematically studied. This paper focuses on the hydrothermal breccia in the Sinongduo deposit, summarizes the characteristics of different types of hydrothermal breccias through drilling core cataloging and petrographic research, aiming at exploring its genesis and relationship with mineralization. The hydrothermal breccias are divided into phreatic breccias, phreatomagmatic breccias and structural hydrothermal breccias. Phreatomagmatic breccias occur in the cryptoexplosive breccia pipe, and is further divided into two types according to the difference of their color and cement compositions. Type A breccia occurs in No.Ⅰ rich ore breccia pipe and the alteration minerals are mainly sericite, montmorillonite and illite. Type B breccia exists in No.Ⅱ lean breccia pipe with alteration minerals being mainly muscovite, hematite and jarosite. The petrogenesis and mineralization of breccia may be the product of different stages of the same geological process, and its ore-bearing property is mainly determined by the properties of the cryptoexplosive fluid. Different degrees of mixing and boiling of atmospheric precipitation and magmatic hydrothermal fluid seem to have been the main reasons for the formation of breccia and mineral precipitation.
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基金项目:本文得到国家重点研发计划-深地课题（编号：2018YFC0604105）、国家自然科学基金（编号：41772075）项目、中国地质调查局项目（编号：DD20190167）和中国地质科学院矿产资源研究所基本科研业务费专项经费（编号：KK2017）联合资助
引用文本：
郝金月,冉凤琴,多吉,唐菊兴,杨宗耀,吴鑫,杨昕,宋壮壮.2021.西藏斯弄多银多金属矿床热液角砾岩特征及成因分析[J].矿床地质,40(3):509~522HAO JinYue,RAN FengQin,DOR Ji,TANG JuXing,YANG ZongYao,WU Xin,YANG Xin,and SONG ZhuangZhuang.2021.Characteristics and genesis of hydrothermal breccias in Sinongduo Ag polymetallic deposit, Tibet[J].Mineral Deposits40(3):509~522
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