八达岭花岗岩的年龄、地球化学特征及其地质意义  

Zircon U-Pb age, geochemistry characteristics of Badaling granitoid complex and their geological significance

作　　者：焦守涛[1,2] 颜丹平[1] 张旗[2] 李承东[3] 万博[2] 田忠华[2] 

机构地区：[1]中国地质大学,北京100083 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国地质调查局天津地质矿产研究所,天津300170

出　　处：《岩石学报》2013年第3期769-780,共12页Acta Petrologica Sinica

基　　金：国家自然科学基金重大研究计划项目(91014001)资助

摘　　要：八达岭花岗岩基是由不同时代、不同类型的花岗岩侵入体组成的,对八达岭花岗岩中的黄花城花岗斑岩、分水岭北西花岗岩和铁炉子二长花岗岩的岩石学、岩相学、地球化学特征及锆石U-Pb年代学研究的结果表明,铁炉子二长花岗岩具有高Sr(312×10-6)、低Yb(0.98×10-6)和高Sr/Yb值(318),属于埃达克型花岗岩,其侵位年龄137Ma;黄花城花岗斑岩具低Sr(193×10-6)、低Yb(1.43×10-6)的特征,属喜马拉雅型花岗岩,其侵位年龄为133Ma;分水岭花岗岩Sr含量很低(10.2×10-6)、低Yb(0.98×10-6)、贫铝(Al2O3=13.66%),且REE图上具明显的负铕异常(Eu/Eu*=0.32),属于南岭型花岗岩,侵位年龄为128.5Ma。研究表明,137Ma的埃达克型花岗岩代表了中国东部高原存续的时间,133Ma的喜马拉雅型花岗岩指示高原可能开始垮塌了,而128Ma的南岭型花岗岩表明高原已经垮塌了。因此,八达岭花岗岩不同类型花岗岩的时代及其Sr、Yb特征可能反映了中国东部高原北部经历了从形成到垮塌的全过程。The Badaling granitoid complex is composed of different ages and types of plutons and is located in the northern margin of the North China Craton. In this study, three plutons, Huanghuacheng granite porphyry, Fenshuiling granite and Tieluzi monzonitic granite, are dated using LA-MC-ICP-MS zircon U/Pb technique and analyzed to obtain whole-rock compositions. The Tieluzi monzonitic granite pluton is dated to be 137±1.2Ma and belongs to adakite-like granite with Sr = 312×10^-6（ 〉 300×10^-6） and Yb = 0. 98×10^-6（ 〈 2. 5 ×10^-6）. The Huanghuacheng granite porphyry body is dated to be 133±1.3Ma and belongs to Himalaya-type granite with Sr = 193 ×10^-6 （ 〈 300 ×10^-6） and Yb = 1.43 x 10 -6 （ 〈 2×10^-6 ）. The Fenshuiling granite pluton is dated to be 128.5±1.2Ma and belongs to Nanling-type granite with very low Sr = 10. 2 ×10^-6 （ 〈 100×10^-6 ） and low A1203 （ A1203 = 13.66% ） and Yb = 0. 98×10^-6 and very negative Eu anomalies （Eu/Eu＊ = 0. 32）. The compositions of these plutons in different ages and different Sr, Yb signatures indicate that the northern East China plateau may have been uplifted before 137Ma and then started to collapse at 133Ma and ended at 130Ma.

关 键 词：八达岭花岗杂岩体 地球化学特征 锆石U-PB年龄 中国东部高原 

分 类 号：P588.121[天文地球—岩石学] P597.3[天文地球—地质学]