东天山三岔口铜矿区矿化岩体SHRIMP U-Pb年代学及锶同位素地球化学特征研究  

Zircon SHRIMP U-Pb Age and Strontium Isotopes of Mineralized Granitoids in the Sanchakou Copper Polymetallic Depoist,East Tianshan Mountains

作　　者：李华芹[1] 陈富文[1] 路远发[1] 杨红梅[1] 郭敬[1] 梅玉萍[1] 

机构地区：[1]中国地质调查局宜昌地质矿产研究所,湖北宜昌443003

出　　处：《地球学报》2004年第2期191-195,共5页Acta Geoscientica Sinica

基　　金：国家重点基础研究发展规划项目 (编号 :G19990 43 2 0 1和 2 0 0 1CB40 910 );国家科技攻关计划"新疆优势矿产资源勘查综合研究"(编号 :2 0 0 1BA60 9A 0 7 18)资助

摘　　要：锆石SHRIMPU Pb年代学及全岩和含矿石英脉锶同位素组成研究表明 ,东天山三岔口铜矿区矿化斜长花岗斑岩的岩浆侵位年龄为 2 78± 4Ma(95 %可信度 ) ,即成岩成矿时代为早中二叠世 ;矿化斜长花岗斑岩、英云闪长 (玢 )岩及含矿石英脉的 (87Sr/ 86Sr) i 在测定误差内一致 ,介于 0 .70 370～ 0 .70 4 37之间 ,而计算得到的εSr(t)值变化于 - 8.5～ +2 .7之间。锶同位素组成特征表明 ,成矿岩体为典型的I型花岗岩 ,可能是幔源火山岩或上地幔物质部分熔融的产物。Zircon SHRIMP U-Pb dating and strontium isotope analyses of granites and copper-bearing quartz veins show that the mineralized plagiogranite porphyry in the Sanchakou deposit of East Tianshan Mountains has an emplacement age of 278±4 Ma(95% Conf.),which means that the rock-forming and ore-forming event took place during early-middle Permian. The( 87 Sr/ 86 Sr)_ i values of mineralized plagiogranite porphyry,tonalite(porphyry)and copper-bearing quartz veins are consistent in test errors,ranging from 0.70370 to 0.70437,and the calculated ε_ Sr ( t )values vary from -8.5 to +2.7,showing that the mineralized intrusions are I-type granitoids and might have been derived from the upper mantle.

关 键 词：锆石SHRIMPU-Pb年代学 锶同位素 东天山 铜矿区 岩浆侵位年龄 

分 类 号：P618.41[天文地球—矿床学] P597.3[天文地球—地质学]