• 责任者：Hu Guyue (State Key Laboratory of Continental Tectonics and Dynamics ; Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Zeng Lingsen
• 刊名：Acta Petrologica Sinica
• 出版年：2011
• 卷期：27(11)
• 关键词：浅成岩 ; hypabyssal rocks ; 二云母花岗岩 ; two-mica granite ; 岩浆作用 ; igneous processes ; 喜马拉雅山 ; Himalayas
• 页码：p.3308-3318
• 图表：6 illus., 3 tables, 54 refs.
• 分类号：0801
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

Recent studies in the Yardoi gneiss dome (YGD) of the Tethyan Himalaya, have demonstrated that the Tethyan Himalayan belt experienced a major episode of crustal melting at Mid-Eocene (44～40 Ma) time, represented by the formation of a suite of high Sr/Y two-mica granites. Petrographic observations, zircon U-Pb age and geochemical data show that: 1) the Lhunze-Qiaga rhyolitic subvolcanic rocks formed at ca.43～41 Ma and may represent the shallow counterpart of the two-mica granites crystallized at a much deeper level; 2) in contrast with the two-mica granites, the subvolcanic rocks had experienced intensive hydrothermal-magmatic interactions as well as An-rich plagioclase fractional crystallization as evidenced by pronounced negative Eu anomalies, much lower Sr concentrations, and enhanced common Pb and U concentrations in the magmatic zircon; and 3) these two suites of rocks formed a Mid-Eocene igneous edifice under crustal thickened conditions.