南秦岭东江口岩体群Pb、Sr和Nd同位素地球化学特征及其对物源的制约  

Pb、Sr AND Nd ISOTOPIC GEOCHEMICAL CHARACTERISTICS OF DONGJIANGKOU PLUTONS IN SOUTHERN QINLING BELT AND CONSTRAINS ON THEIR SOURCES

作　　者：朱茂旭[1] 骆庭川[2] 张宏飞[2] 

机构地区：[1]中国科学院地球化学研究所,贵阳550002 [2]中国地质大学地球化学研究所,武汉430074

出　　处：《地质地球化学》1998年第1期30-36,共7页Geology-Geochemistry

摘　　要：以区域地球化学研究成果为基础，通过Pb、Sr、Nd同位素特征分析，揭示出东江口岩体群的Pb同位素特征与南秦岭东段基底具有耦合关系，而与其它构造单元则存在明显的差异，204Pb-207Pb／206Pb，204Pb-208Pb／206Pb图解研究表明，该岩体群为下地壳源花岗岩类，Nd同位素特征（tDN和εNd（t））表明，耀岭河群最适合于作为岩体群的主要物源。该岩体群和耀岭河群的Sr同位素存在一定的差别，这可能是由于南秦岭在280－200Ma间强烈的地质作用使Rb－Sr同位素体系改造所致。Studies of the Pb isotopic characteristics show a coupling of Pb isotopic composition betweenDongjiangkou plutons and the basement of the eastern part of southern Qinling. 204Pb vs. 207Pb/206Pband 204Pb vs. 208Pb/206Pb diagrams indicate that the source of Dongjiangkou plutons is characteristic ofthe basement of the lower crust which has undergone high-grade metanlorphism. Similarities in Ndisotopic characteristics between Dongjiangkou plutons and the Yaolinghe Group imply that the Yaolinghe Group is the most possible source of Dongjiangkou plutons in the eastern part of southern Qinlinghelt.

关 键 词：东江口 岩体群 同位素地球化学 物源 铅 锶 

分 类 号：P597[天文地球—地球化学] P583[天文地球—地质学]