赣东北鹅湖岩体SHRIMP锆石U-Pb年龄、Sr-Nd-Hf同位素地球化学与岩石成因  

SHRIMP Zircon U-Pb Age,Sr-Nd-Hf Isotopic Geochemistry and Petrogenesis of the Ehu Pluton in Northeastern Jiangxi Province

作　　者：赵鹏[1,2] 姜耀辉[1,2] 廖世勇[1,2] 周清[1,2] 靳国栋[1,2] 

机构地区：[1]南京大学地球科学与工程学院 [2]内生金属矿床成矿机制研究国家重点实验室(南京大学),南京210093

出　　处：《高校地质学报》2010年第2期218-225,共8页Geological Journal of China Universities

基　　金：国家自然科学基金重点项目(40730313)资助

摘　　要：对赣东北鹅湖岩体进行了SHRIMP锆石U-Pb年代学、元素和Sr-Nd-Hf同位素地球化学及岩石成因研究。SHRIMP锆石U-Pb定年结果表明,鹅湖岩体形成于早白垩世的(121.7±2.9)Ma;岩相学及元素和Sr-Nd-Hf同位素特征表明鹅湖花岗岩属于S型,主要是由地壳深处(至少40km)的古元古代变质沉积岩发生部分熔融形成的,成岩过程中并没有发生强烈的分离结晶作用和幔源岩浆混合作用,赣东北地区早白垩世伸展构造背景造成的软流圈地幔上涌可能是下地壳岩石发生部分熔融的诱因。In this study,we present detailed SHRIMP zircon U-Pb chronology,major and trace elements,and Sr-Nd-Hf isotope data for the Ehu pluton in northeastern Jiangxi province,in an attempt to better constrain its petrogenesis.SHRIMP zircon U-Pb dating shows that the Ehu pluton was emplaced in the Early Cretaceous（121.7 Ma±2.9 Ma）.Petrographic,elemental and Sr-Nd-Hf isotopic characteristics suggest that the Ehu granites are of S-type,generated by partial melting of Paleoproterozoic metasedimentary basement in the deep（40 km）crust,with no fractional crystallization and mantle-derived magma mixing in their evolution.The upwelling of asthenosphere during the Early Cretaceous extensional tectonic regime in the region induced partial melting of the lower crust.

关 键 词：鹅湖花岗岩 赣东北 SHRIMP锆石U-PB年龄 SR-ND-HF同位素 

分 类 号：P578.941[天文地球—矿物学] P597.3[天文地球—地质学]