气候变化领域集成服务门户(CCPortal): Origin of K-feldspar megacrysts of Quxu batholith in Gangdese belt, South Tibet: Implication for magma rejuvenation in a crystal mush reservoir

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DOI	10.1016/j.lithos.2023.107019
	Origin of K-feldspar megacrysts of Quxu batholith in Gangdese belt, South Tibet: Implication for magma rejuvenation in a crystal mush reservoir
	Yu, Yuzhi; Luo, Biji; Zhang, Hongfei; Xu, Wangchun; Yang, He; Pan, Fabin; Guo, Liang; Li, Jiacheng; Ruan, Bing; Lai, Ke; Zhang, Yunxuan; Cao, Zhenping
发表日期	2023
ISSN	0024-4937
EISSN	1872-6143
卷号	438
英文摘要	The origin of the K-feldspar megacrysts is still controversial and how magmas move in crystal-rich reservoir and the mechanism of the reactivation of crystal mushes after rheological locking are still elusive. K-feldspar megacryst in granitoids is a good candidate to constrain these issues. We carried out an integrated study of field geology, crystal size distribution (CSD), LA-ICP-MS zircon U-Pb geochronology, whole-rock geochemistry, and in-situ major and trace elements and Pb isotopic compositions of K-feldspar megacrysts from the monzogranites and mafic microgranular enclaves (MMEs) of the Quxu batholith in the Gangdese belt, southern Tibet. The Quxu monzogranites have a magma crystallization age of similar to 50 Ma. Some elements (e.g., Al, Sr, Cr and Ni) of the Quxu monzogranite and MMEs show scatter and no linear variations with increasing SiO2, indicating that simple magma mixing between mafic and felsic endmembers is unconspicuous for the formation of the Quxu monzogranites. The K-feldspar megacrysts from the Quxu monzogranites and MMEs can be divided into three types: normal zoning, reverse zoning and oscillatory zoning or no zoning. In-situ major and trace element of the Kfeldspar megacrysts, combined with their variation in-situ Pb isotopic composition (Pb-206/Pb-204 = 18.41-18.80, Pb-207/Pb-204 = 15.42-15.75 and Pb-208/Pb-204 = 38.29-39.06), indicate that the Quxu monzogranites were formed by the assembly of multiple heterogeneous magma pulses. The CSD results suggest that K-feldspar megacrysts have a longer residence time of 0.14-0.33 k.yr to 4.1-52 k.yr. We suggest that K-feldspar megacrysts could grow prolongedly via crystals transfer or magma injection of different batches in melt-present environments, and magma mush in cold-stored could be rejuvenated by the repeatedly recharging of hot magma pulses.
关键词	K-feldspar megacrysts Crystal size distribution Magma reservoir Magma mush rejuvenation Gangdese batholith
英文关键词	SIZE DISTRIBUTION CSD; PB ISOTOPE; ICP-MS; INTRUSIVE COMPLEX; ROCKS; PLUTON; EVOLUTION; SYSTEM; GROWTH; CRYSTALLIZATION
WOS研究方向	Geochemistry & Geophysics ; Mineralogy
WOS记录号	WOS:001012132900001
来源期刊	LITHOS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/283329
作者单位	China University of Geosciences - Wuhan; Chinese Academy of Sciences; Xinjiang Institute of Ecology & Geography, CAS; Tianjin University
推荐引用方式 GB/T 7714	Yu, Yuzhi,Luo, Biji,Zhang, Hongfei,et al. Origin of K-feldspar megacrysts of Quxu batholith in Gangdese belt, South Tibet: Implication for magma rejuvenation in a crystal mush reservoir[J],2023,438.
APA	Yu, Yuzhi.,Luo, Biji.,Zhang, Hongfei.,Xu, Wangchun.,Yang, He.,...&Cao, Zhenping.(2023).Origin of K-feldspar megacrysts of Quxu batholith in Gangdese belt, South Tibet: Implication for magma rejuvenation in a crystal mush reservoir.LITHOS,438.
MLA	Yu, Yuzhi,et al."Origin of K-feldspar megacrysts of Quxu batholith in Gangdese belt, South Tibet: Implication for magma rejuvenation in a crystal mush reservoir".LITHOS 438(2023).