40Ar/39Ar chronology and geochemistry of high-K volcanic rocks in the Mangkang basin,Tibet
Our two newly obtained high-quality 40Ar/39Ar ages suggest that the high-K volcanic rocks of the Lawuxiang Formation in the Mangkang basin, Tibet were formed at 33.5 ( 0.2 Ma. The tracing of elemental and Pb-Sr-Nd isotopic geochemistry indicates that they were derived from an EM2 enriched mantle in continental subduction caused by transpression. Their evidently negative anomalies in HFSEs such as Nb and Ta make clear that there is an input of continental material into the mantle source. The high-K rocks at 33.5 ( 0.2 Ma in the Mangkang basin may temporally, spatially and compositionally compare with the early one of two-pulse high-K rocks in eastern Tibet distinguished by Wang J. H. Et al., implying that they were formed in the same tectonic setting.
作 者： Zhang Huihua HE HuaiYu Wang Jianghai Xie Guanghong 作者单位： Zhang Huihua,Xie Guanghong(Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China)HE HuaiYu(Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China)
Wang Jianghai(College of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China;Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China)
刊 名： 中国科学D辑（英文版） SCI 英文刊名： SCIENCE IN CHINA (EARTH SCIENCES) 年，卷(期)： 2005 48(1) 分类号： P59 关键词： Cenozoic high-K volcanic rocks 40Ar/39Ar chronology Mangkang basin Tibet