地质通报2018，Vol.37Issue(5)：908-919,12.
胶东金矿成矿时代及区域地壳演化——基性脉岩的SHRIMP锆石U-Pb年龄及其地质意义
Metallogenic epoch and regional crust evolution in the Jiaodong gold deposit, Shandong Province: Evidence from SHRIMP zircon U-Pb ages of mafic dykes
摘要
Abstract
Although mineralogenetic epoch of the Jiaodong gold deposit in Shandong Province has been studied by many previous researchers,the accurate time frame of mineralization remains undecided.This paper reports SHRIMP zircon ages and oxygen isotopic values for pre-metallogenic and post-metallogenic mafic dykes in the Jiaojia gold deposit of Jiaodong Peninsula.In CL photos,the igneous zircons show good crystal form and clear zoning.Two samples from pre-metallogenic mafic dykes have recorded concordant ages of 124.9±1.8Ma(n=2,MSWD=2.2) and 124.2±1.1Ma (n=2,MSWD=0.50).A sample from post-mineralization lamprophyre yielded a concordant age of 112.2±0.7Ma(n=1),and therefore the emplacement age of the pre-metallogenetic mafic dykes is ≤124.9Ma and ≤124.2Ma.The emplacement age of the post-mineralization lamprophyre is ≤112.2Ma.The metallogenic age of the Jiaojia gold deposit is ≤124.2Ma.These data indicate that time limitation of mineralization of the Jiaojia gold deposit should be from 124Ma to 112Ma.Besides,the obtained multiple stages of inherited zircon ages from the samples have recorded the magmatic and/or metamorphic events of Jurassic,Triassic,Paleozoic,Neoproterozoic,Mesoproterozoic and Neoarchean.This suggests that,in addition to Neoarchean,Mesoproterozoic and Neoproterozoic geological bodies in North China Craton,there are also Paleozoic and Triassic geological bodies from Sulu orogenic belt in the depth of the Jiaobei uplift.These data suggest that the materials of the Sulu ultrahigh-pressure metamorphic belt was thrusting under the Jiaobei uplift.The δ18O values of zircons vary from 3.86‰ to 11.37‰,and this indicates that different stages of zircons have diverse oxygen isotope compositions and diversifted material sources.关键词
SHRIMP锆石U-Pb年龄/煌斑岩/金矿化/氧同位素/山东省焦家金矿床/成矿时代Key words
SHRIMP U-Pb zircon ages/lamprophyre/gold mineralization/oxygen isotopes/Jiaojia gold deposit in Shandong Province/metallogenic epoch分类
天文与地球科学引用本文复制引用
宋英昕,宋明春,孙伟清,马晓东,李大鹏..胶东金矿成矿时代及区域地壳演化——基性脉岩的SHRIMP锆石U-Pb年龄及其地质意义[J].地质通报,2018,37(5):908-919,12.基金项目
国家自然科学基金项目《探索胶东金矿成矿物质来源的新证据—岩石学、矿物学约束》(批准号:41503038)、泰山学者工程《胶东型金矿的构造岩浆背景和深部找矿关键技术》(编号:ts201511076)和山东省重点研发计划项目《深部金矿理论、方法与预测》(编号:2017CXGC1604) （批准号:41503038）
