Enrichment of Mantle-derived Fluids in the Formation Process of Granitoids: Evidence from the Himalayan Granitoids around Kunjirap in the Western Qinghai-Tibet Plateau

• Published in: Acta geologica Sinica (Beijing) Vol. 76; no. 3; pp. 343 - 350
• Main Authors: Yaohui, JIANG, Hongfei, LING, Shaoyong, JIANG, Xunruo, ZHOU, Xingjian, RUI, Wanzhi, YANG
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2002
• Subjects: fluid; granitoid; mantle-derived; mantle-derived fluid; plateau; Qinghai-Tibet; western; western Qinghai-Tibet plateau
• ISSN: 1000-9515; 1755-6724
• DOI: 10.1111/j.1755-6724.2002.tb00551.x

Taking the Himalayan granitoids around Kunjirap in the western Qinghai-Tibet plateau as an example, the authors present in this paper the characteristics of the granitoids rich in mantle-derived fluid components and discuss their rock-forming mechanism. The research results indicate that the rock assemblage of the studied granitoids involves diopside syenite-diopside granite-biotite (monzonitic) granite, consisting mainly of K-feldspar, oligoclase, quartz, iron-phlogolite, diopside and edenite. The rocks are rich in mantle-derived fluid components of volatiles including F, alkali metal elements such as K, Na, Rb, Sr and Ba, and radiogenic heat-producing elements such as U and Th. They were generated by the influx of mantle-derived fluids into the lower crust to give rise to partial melting during the lithosphere thinning in the Qinghai-Tibet plateau.