北祁连奥陶系阴沟群中蒲花沟铜矿成矿类型及成因分析

Metallogenic Types and Genesis Analysis of the Puhuagou Copper Deposit in Ordovician Yingou Group in North Qilian

北祁连蒲花沟铜矿位于北祁连加里东造山带,赋存于奥陶系阴沟群之中。北祁连奥陶系阴沟群是一套典型的北祁连山火山岩型矿床含矿地层,因此是研究蒲花沟铜矿的理想地层。笔者从矿床角度出发,立足于详实的区域地质勘查资料,结合前人已取得的众多重要研究成果,在总结研究区阴沟群地质特征及铜矿化带、矿体和矿石特征的基础上,分析研究蒲花沟铜矿成矿类型及成因。结果表明,北祁连蒲花沟铜矿类型为破碎带蚀变岩型铜矿,成矿物质主要来源于奥陶系阴沟群,主要容矿围岩为孔雀石化碎裂英安质晶屑凝灰岩,成矿热动力来源于受北祁连在加里东运动末期(晚志留世)局部岩浆活动影响而于蒲花沟一带发育的酸性侵入体。

The Puhuagou Copper deposit,located in the North Qilian Caledonian orogenic belt,is occurred in the Ordovician Yingou group.The Ordovician Yingou group in Northern Qilian is a typical ore-bearing stratum of volcanic-type deposit in North Qilian Mountains,so it is an ideal stratum for the studying the Puhuagou Copper deposit.Based on the detailed geological exploration data and combined with many important previous research results,the geological characteristics of Yingou group,copper mineralized belt,ore-body and ore have been summarized in this paper.And then,the metallogenic types and genesis of the Puhuagou copper deposit have been analyzed and studied.The results show that the Puhuagou copper deposit belongs to the altered rock-type copper deposit and has been controlled by the fracture zone.The ore-forming materials are mainly derived from the Ordovician Yingou group,the main ore-bearing rock is the malachitization fragmented dacitic crystal tuf.The ore-forming thermal source is derived from the localmagmatic activity of North Qilian at the end of the Caledonian movement（Late Silurian）,and then the acidic intrusive body was depoloped in Puhuagou area.