西北地质2018，Vol.51Issue(1)：54-64,11.
甘肃北山地区花牛山群变英安岩LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义
LA-ICP-MS Zircon U-Pb Age, Geochemistry and Tectonic Implications of Metamorphic Dacite from Huaniushan Group in Beishan Area, Gansu, China
摘要
Abstract
By using the zircon LA-ICP-MS U-Pb dating,the obtained ages of metamorphic dacite from Huaniushan Group are (454.7 ± 0.87) Ma (MSWD=0.28),which belong to the early stage of Late Ordovician.This age can provide a new basis for accurately determining the depositional age of Hunshan Group,thus the age of Hunshan Group has been revised as Upper Ordovician.This metamorphic dacite have high alkali and high Al,obvious enrichment of Rb,Th,U,K,Pb,negative anomalies of Nb,Ta,Ti,no obvious δEu anomaly,showing the typical volcanic magma characteristics.According to the regional geological data,the metamorphic dacite is formed in the active continental margin,which is related to the addition of subduction fluid or subduction sediments and is different from the formation of massive sulfide deposits in the Huaniushan Pb-Zn deposit.Therefore,it is considered that the Huaniushan Group is not the orebearing strata of Huaniushan Pb-Zn deposit.关键词
火山弧/赋矿层位/锆石U-Pb年龄/变英安岩/花牛山群/甘肃北山Key words
volcanic arc/ore-bearing strata/zircon U-Pb age/metamorphic dacite/Huaniushan Group/Beishan in Gansu分类
天文与地球科学引用本文复制引用
谢建强,第鹏飞,杨婧,陈万峰,魏海峰,翟新伟..甘肃北山地区花牛山群变英安岩LA-ICP-MS锆石U-Pb年龄、地球化学特征及其地质意义[J].西北地质,2018,51(1):54-64,11.基金项目
中国地质调查局“甘肃北山营毛沱-玉石山地区铁铜金钨多金属矿整装勘查区关键基础地质研究”(12120114014501)、国家自然科学基金项目“峨眉山大火成岩省钒钛磁铁矿矿床成矿机制的流体组成制约”(41472070)和中央高校基本科研业务费专项资金“金川Ni-Cu硫化物矿床成矿过程的Mg同位素组成示踪”(lzujbky-2017-77)资助 （12120114014501）
