川西乡城-滇西北洛吉地区燕山期花岗岩及铜钼多金属成矿作用  

The Yanshanian Granites and Coppe-Molybdenum Polymetallic Mineralization in the Luoji-Xiangcheng Area Between Western Sichuan and Northwestern Yunnan

作　　者：蒋成兴 尹光候 杨艳 余海军 卢映祥 

机构地区：[1]云南省地质调查局,云南昆明650051 [2]云南省地质技术信息中心,云南昆明650051

出　　处：《地质与勘探》2013年第6期1017-1035,共19页Geology and Exploration

基　　金：国家重点基础研究发展计划项目(编号:2009CB421007);中国地质调查局地质调查工作项目(编号:资[2010]矿评01-06-26)联合资助

摘　　要：川西与滇西北接壤的乡城-洛吉地区，经过印支期甘孜-理塘洋俯冲-消减于中咱地块之下，将中咱地块（义敦岛弧）、扬子地块焊接成一体之后，进入整体演化阶段。即254～203Ma之后，65Ma喜马拉雅期碰撞造山之前的76～85Ma间，发育了南北向展布的乡城一洛吉燕山期过铝质一弱铝质A型花岗岩带，由二长花岗岩-花岗斑岩等组成，属于岛弧基础之上经历了岛弧岩浆作用的陆壳，或大陆碰撞旋回的异常地壳（幔源岩浆岩、碰撞造山，地壳加厚）派生富碱和铝、贫水的A型花岗岩。发育强烈的铜钼多金属成矿作用，形成岩体边部角岩带内细脉状黄铜矿及团块状辉钼矿化；中部蚀变花岗岩内的辉钼矿石英脉、稀疏粗晶和浸染状辉钼矿；沿裂隙发育石英-辉钼矿脉3种成矿类型。The Xiangcheng-luoji area straddles the border between western Sichuan and northwestern Yunnan. During Indosinian the Zhongza block （ i. e. Yidui island arc） and Yangzi block were welded to each other, as a whole they commenced the integrated evolution stage, with the Garze-Litang ocean being subducted beneath the Zhongza block. That is, after 254 -203Ma, a north-south striking Luoji-Xiangcheng Yanshanian peraluminous to meta- luminous A-type granitic belt developed during 76 ~ 85Ma prior to Himalayan orogenic collision at 65Ma, that comprises adamellite to granitcporphyry. It was an alkali-and aluminum-rich, and water-lack A-type granite, which derived from the continental crust formed from an island arc by island arc mag- matism or abnormal crust by a continental collision cycle （ mantle-derived magmatic rock, collision orogeny and crustal thickening）. The strong copper and molybdenum polymetallic mineralization occurred in the belt, forming mainly thin vein ehalcopyrite mineralization in the hornfcls zone of the outer margin of magmatic intrusions with molybdenite in briquets with concentration; molybdenite mineralization forming molybdenite quartz veins, sparsely coarse crystal and disseminated molybdenitc in alteration granite in the middle of that; and 3 types of quartz-molybdenite vein mineralization occurred in the fraclutes.

关 键 词：燕山期 A型花岗岩 地球化学 铜钼成矿 乡城 洛吉 

分 类 号：P618.44[天文地球—矿床学]