摘要
三江成矿带北段治多-玉树地区已显示出较大的铜多金属矿成矿潜力。在已有研究成果的基础上,结合详细的野外调查和室内研究,对三江北段治多-玉树地区新发现的典型铜多金属矿床的地质特征、成因类型和成矿构造环境进行了综述。这些矿床普遍赋存于中酸性火山岩中,空间上具"火山碎屑岩-矿体-热水沉积岩"的分布特征。矿体多为层状、似层状,且矿石品位较高。对比研究表明,治多-玉树地区铜多金属矿床地质特征与四川呷村矿床和日本"黑矿"矿床相似,成矿流体可能系岩浆水和海水的混合流体;成矿物质可能源于岛弧岩浆作用,并含有热液交代围岩所萃取的金属元素。研究结果表明该区以火山岩为赋矿围岩的铜多金属矿床应归属为VHMS型,成矿构造环境可能与晚三叠世甘孜-理塘洋向南俯冲的大洋岛弧-大陆边缘岛弧环境有关。
Zhiduo-Yushu area,in the north part of Sanjiang metallogenic belt,shows great mineralization potential for copper-polymetallic deposits.Based on the previous researches,field investigations and indoor collations,this paper tentatively makes a comprehensive elucidation of the geological features,genetic types and tectonic setting of newly-found and typical copper-polymetallic deposits in Zhiduo-Yushu area,northern Sanjinag.These copper-polymetallic deposits have the features of ＂vocaniclasitic rocks-ore bodieshydrothermal sedimentary rocks＂ in spatial terms.Layered or layer-like ore bodies with relatively high ore grade are mainly hosted in the intermediate-acid andesitic or dacitic volcaniclastics.Based on the comparison of the characteristics,we assume that copper-polymetallic deposits in Zhiduo-Yushu area are similar to the Gacun deposits and Japanese Kuroko deposits.Ore-forming fluid might came from the fluid mixed with magmatic water and sea water and ore-forming materials might be derived from arc magmatism as well as extraction by hydrothermal metasomatism.These vocanic rocks-hosted copper-polymetallic deposits can be divided into VHMS-type deposits.Furthermore,after preliminarily discussing the geological setting of the deposits,we suggest that these deposits formed in the setting of oceanic arc-continental margin arc,during southward subduction of Garzê-Litang ocean in Upper Triassic.
出处
《地质科技情报》
CAS
CSCD
北大核心
2017年第1期140-151,共12页
Geological Science and Technology Information
基金
中国地质调查局项目"青海省多彩地区铜多金属矿整装勘查区关键基础地质研究"(科[2014]04-025-081)
