新疆准噶尔北缘早石炭世金-铜-钼成矿事件:年代学证据  

The Early Carboniferous gold-copper-molybdenum mineralization events in the northern margin of Junggar Basin,Xinjiang: Geochronological evidence

作　　者：王玉往[1] 王京彬[1] 龙灵利[1] 丁汝福[2] 石煜[3] 赵路通[4] 

机构地区：[1]北京矿产地质研究院,北京100012 [2]有色金属矿产地质调查中心,北京100012 [3]中国地质大学地球科学与资源学院,北京100083 [4]昆明理工大学国土资源工程学院,昆明650093

出　　处：《岩石学报》2015年第5期1448-1460,共13页Acta Petrologica Sinica

基　　金：国家重点基础研究发展规划项目(2014CB440803;2007CB411304);国家自然科学基金项目(41202064);中国地质调查局老矿山深部与外围找矿项目(121200113086300)联合资助

摘　　要：新疆准噶尔北缘地区已发现多处大中型内生金属矿床,它们主要形成于2个构造-岩浆活动期,即泥盆纪洋陆俯冲期的岛弧型斑岩铜（金）矿,二叠纪后碰撞造山期的铜镍硫化物型矿床和造山型（或剪切带型）Au矿。作者近年来在对该区地质构造和矿床研究中获得了一批早石炭世成岩成矿年代学数据：除已发表的希勒库都克斑岩铜钼矿床流纹斑岩（329Ma）和辉钼矿（327Ma）年龄外,本文工作新近获得201金矿闪长岩年龄为324Ma、科克森套地区花岗闪长斑岩年龄为328Ma、库尔吐班套地区花岗岩年龄为323Ma、阿克塔斯Au矿区花岗闪长岩年龄为327Ma,这些年龄数据集中在323～328Ma,即早石炭世（主要在维宪阶和谢尔普霍夫阶）。综合分析认为,该区在早石炭世洋盆已经闭合进入碰撞造山阶段,该阶段岩浆活动以出露小规模中酸性岩脉、岩株为特征,构造活动和壳幔相互作用强烈,主要成矿类型有斑岩型Cu Mo矿、浅成低温热液型Au矿、脉岩-构造蚀变岩型Au矿,构成一独特的与浅成岩有关的早石炭世金-铜-钼成矿带。Many large-scale to medium-sized endogenetic metallic deposits proved up in north margin of Junggar Basin（ NMJB） of Xinjiang,which are mainly formed in two periods of tectonic-magmatic activity with ocean-continent subduction period and postcollisional orogeny period,are the Devonian island arc porphyry type Cu-Au deposit of earlier period and the Permian Cu-Ni sulfide deposit and orogenic type Au deposit（ or shear zone type Au deposit） of later period. Now,a number of Early Carboniferous diagenetic and metallogenetic geochronology data of this area are obtained during this work： the ～ 324 Ma for diorite in ＂201 ＂Au deposit, ～328Ma for granodiorite-porphyry in Kekesentao area, ～ 323 Ma for granite in Tuerkubantao area,and ～ 327 Ma for granodiorite in Aketasi Au deposit. These data concentrate in 323 ～ 328 Ma of the Early Carboniferous. It is inferred that the study area may be in collisional orogenic stage during the Early Carboniferous Epoch through comprehensive analysis. The events of tectonic activity and crust-mantle interaction occurred frequently in this stage,which was quite favorable for ore-forming with porphyry type Mo-Cu,epithermal type Au, and dyke structure altered rock type Au mineralization. Thus, it is considered that there was an Early Carboniferous Au-Cu-Mo metallogenetic belt associated with hypabyssal rock spreading along northern margin of Junggar Basin.

关 键 词：锆石U-PB定年 早石炭世 斑岩型Cu-Mo-Au矿床 碰撞造山 中亚造山带 北准噶尔 新疆 

分 类 号：P597.3[天文地球—地球化学]