中文摘要：

本文对躬穷左波Fe-Cu矿区出露的三套酸性侵入岩进行了系统的LA-ICP-MS锆石U-Pb年代学和岩石地球化学研究。年代学测试结果显示花岗斑岩、二长花岗斑岩和钾长花岗岩206Pb/238U加权平均年龄分别为147.0Ma、143.6Ma和142.8Ma,矿区存在晚侏罗世—早白垩世存在3期岩浆事件。岩石地球化学组成特征显示,花岗斑岩属准铝质-弱过铝质I型花岗岩;二长花岗斑岩为高钾钙碱性系列,属弱过铝质I型花岗岩;钾长花岗岩经历了强烈的结晶分异作用,属高分异I型花岗岩。岩石微量元素富集Rb、Th、U、Pb而亏损Nb、Ta、Ti、P元素,Nb/Ta比值接近大陆地壳组成及锆石负的εHf(t)值特征,指示成岩物质以壳源物质为主。躬穷左波晚侏罗世矽卡岩型Fe-Cu矿化事件的发现对于完善班—怒带西段成矿规律和指导区域找矿工作具有重要意义。

英文摘要：

This paper reports systematic research about LA-ICP-MS zircon U-Pb age,whole-rock major and traceelement of three acid intrusives from the Gongqiongzuobo Fe-Cu deposit.The result of Geochronology testingshows that the weighted average age are147.0Ma(Granite porphyry),143.6Ma(Monzonitic granite porphyry)and142.8Ma(K-feldspar granite)respectively and finds there are three periods of magma activity inGongqiongzuobo area during Late Jurassic–Early Cretaceous Epoch.The result of geochemistry characteristicsshows that(1)Granite porphyry belongs to aluminum-weakly peraluminous I-type granite,(2)Monzonitic graniteporphyry is high potassium calc-alkine series and belongs to weakly peraluminous I-type granite,(3)K-feldspargranite has experienced strong crystallization differentiation and belongs to high differentiation I-type granite.Those rocks enrich in Rb Th U Pb and deplete in Nb Ta Ti P,their Nb/Ta ratio are close to continental crust andthe zircon has negativeεHf(t)value.All these feature implys rock-forming materials are mainly come from thecrust-source.The discoveray of Late–Jurassic skarn-type mineralization has important significance forconsummating regional metallogeny and directing regional prospecting.