地质通报2016，Vol.35Issue(6)：894-905,12.
西藏仲巴地块加达钾质火山岩LA-ICP-MS锆石U-Pb年龄和地球化学特征
LA-ICP-MS zircon U-Pb age and geochemical characteristics of Jiada potas-sic volcanic rocks in Zhongba terrane, Tibet
摘要
Abstract
Cenozoic potassic volcanic rocks are widely distributed in the Tibetan Plateau, mainly in northern Tibet and Lhasa block with a few reports in Zhongba terrane. The study of Jiada potassic volcanic rocks found in Zhongba terrane shows that the rocks are almost exclusively trachyte, and the magma erupted incessantly by overflowing and erupting. These rocks are also characterized by high potassium and high aluminum, rich LILE, LREE and Sr, and poor HFSE,Y and Yb, with Eu negative anomaly. Their geochemi⁃cal characteristicss are similar to those of typical adkite rocks. The LA-ICP-MS zircon U-Pb age of trachyandesites is 17.03 ± 0.32Ma, which means that these volcanic rocks were formed in Miocene. The Jiada potassic magma was derived from partial melting of thickened crust. The rocks represent post-collisional tectonic setting and extension environment.关键词
钾质火山岩/埃达克岩/地球化学特征/LA-ICP-MS锆石U-Pb年龄/仲巴地块Key words
potassic volcanic rock/adakite/geochemical characteristics/LA-ICP-MS zircon U-Pb age/Zhongba terrane分类
天文与地球科学引用本文复制引用
杨硕,向树元,张先,李志璇,刘桢何..西藏仲巴地块加达钾质火山岩LA-ICP-MS锆石U-Pb年龄和地球化学特征[J].地质通报,2016,35(6):894-905,12.基金项目
中国地质调查局项目 （）
