阿尔泰蒙库铁矿斜长角闪岩锆石SHRIMPU-Pb年龄及地质意义  

Shrimp U-Pb Age of the Amphibolite from Mengku Iron Deposit and its Geological Implications in Altay,Xinjiang

作　　者：张保江[1] 李强[2] 耿新霞[2] 杨富全[2] 刘锋[2] 

机构地区：[1]河北省地矿局第四水文工程地质大队,河北沧州061000 [2]中国地质科学院矿产资源研究所,国土资源部成矿作用与资源评价重点开放实验室,北京100037

出　　处：《新疆地质》2012年第3期277-282,共6页Xinjiang Geology

基　　金：国家自然科学基金项目(40672065);国家科技支撑计划项目(2011BAB06B03-02;2006BAB07B02-01)联合资助

摘　　要：蒙库大型铁矿位于阿尔泰南缘麦兹盆地,赋存于康布铁堡组变质火山-沉积岩系中,容矿岩石为石榴石矽卡岩、变粒岩、浅粒岩、斜长角闪岩和大理岩。矿体总体顺层分布,空间上与矽卡岩密切相关。对9号矿体围岩斜长角闪岩锆石SHRIMP U-Pb年龄进行了测定,12颗锆石的206Pb/238U加权平均年龄为(403.9±4.8)Ma(MSDW=1.3)。结合区域年代学资料,限定康布铁堡组形成时代为晚志留—早泥盆世,同时限定蒙库铁矿形成时代小于404 Ma。The Mengku large-size iron deposit occurs in metavolcanic-sedimentary sequence of the Kangbutiebao Formation in the Maizi Basin of south Altay, with the host rocks being garnet skarn,granulitite,leucogranulitite,amphibolite and marble. Orebodies are largely concordant with the bedding of the strata,and the distribution of the orebodies is spatially related to skam.Precise SHRIMP U-Pb dating of zircon from the amphibolite in the No.9 orebody wall rock of the Mengku iron deposit has been carded out in this study.The results show that the weighted average 206pb/238U age of the 12 zircon grains is （403.9±4.8） Ma （MSDW=1.3）.A combination of the ages of Kangbutiebao Formation in the region limits the Kangbutiebao Formation is of Late Silurian-Early Devonian,and constraining the age of the Mengku iron deposit to〈404 Ma.

关 键 词：阿尔泰 蒙库铁矿 锆石SHRIMPU-PB年龄 斜长角闪岩 

分 类 号：P618.31[天文地球—矿床学] P597.3[天文地球—地质学]