• 责任者：Xiang Hua (State Key Laboratory of Continental Tectonics and Dynamics ; Institute of Geology ; Chinese Academy of Geological Sciences ; Beijing 100037 ; China) ; Zhang Zeming
• 刊名：Acta Petrologica Sinica
• 出版年：2013
• 卷期：29(11)
• 关键词：高压变质作用 ; high pressure metamorphism ; 深熔作用 ; anatexis ; 喜马拉雅构造带 ; Himalaya Tectonic Zone
• 页码：p.3792-3802
• 图表：6 illus., 2 tables, 79 refs.
• 分类号：0802
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

     The Namche Barwa complex （NBC） in Eastern Himalayan Syntaxis, is generally interpreted as a part of the Higher Himalayan Crystalline Series. The Namche Barwa complex experienced high pressure （HP） metamorphism during the deep subduction of the Indian continent beneath Eurasian continent. In this paper, based on petrology and mineral chemistry, phase equilibria modeling was carried out for high-pressure pelitie rocks of NBC. This results show that the pelitic rocks have suffered HP granulite facie metamorphism, with a peak-metamorphic assemblage of garnet ＋ kyanite ＋ biotite ＋ plagioclase ＋ k-feldspar ＋ quartz ＋ rutile, and a peak-metamorphic condition of - 820℃ and 13.0 - 13.5kb. This indicates the Indian continent subducted to more than 45km depth and formed the thickened lower ernst of the Tibetan Plateau. This research also indicates the HP pelitie rocks have undergone dehydration melting of muscovite and biotite under HP granulite facies conditions, and may produce up to 27vo1% granitic melt, which may be the source of leucogranites in Himalayan orogeny. Thus, Qinghai-Tibet Plateau has a partly melted thickened lower crust, and provides advantageous rheologieal conditions for lateral flow.