地质科学2013，Vol.48Issue(2)：484-500,17.DOI:10.3969/j.issn.0563-5020.2013.02.011
西藏措勤晚白垩世英安岩的厘定与地球化学特征
Geochemical characteristics of the Late-Cretaceous dacite in Coqen,western Gangdese batholith, Tibet
摘要
Abstract
Field investigations and zircon SHRIMP U-Pb dating show that a suite of dacite formed at Late Cretaceous (88.5 ±1.2 Ma) occurred in the southeast of Coqen, western Gangdese Batholith, Tibet. This suite of volcanic rocks is characterized by trace element geochemistry similar to those formed in the arc environment. Geochmical and isotopic data indicate that they are Ⅰ-type igneous rocks and have experienced high degrees of plagioclase fractional crystallization. As compared to those intrusive rocks of similar ages, this suite of rocks represents highly evolved magmas drieved from partial melting of deep crustal mafic rocks and is characterized by elevated Rb/Sr but lower Sr/Y ratios. Our new data as well as those from the literature further indicate that the Lhasa terrane had experinecd extensive magmatism at 90 ～ 85 Ma due to northward subduction the Neo-Tethyan oceanic lithosphere beneath the Lhasa terrane.关键词
岛弧岩浆作用/火山岩/拉萨地块/锆石U/Pb定年/Hf同位素地球化学Key words
Island arc magmatism, Volcanic rocks, Lhasa terrane, Zircon U-Pb age,Hf isotope geochemistry分类
天文与地球科学引用本文复制引用
王伟,曾令森,刘静,肖萍,高利娥..西藏措勤晚白垩世英安岩的厘定与地球化学特征[J].地质科学,2013,48(2):484-500,17.基金项目
国家重点基础研究发展计划"973"项目(编号:2011CB403102)和国家自然科学基金项目(编号:41073024,41273034)资助. （编号:2011CB403102）
