气候变化领域集成服务门户(CCPortal): Sequential melting of deep crustal source rocks in a rift system: An example from southern Tibet

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DOI	10.1016/j.chemgeo.2022.121295
	Sequential melting of deep crustal source rocks in a rift system: An example from southern Tibet
	Gao, Li-E; Zeng, Lingsen; Zhao, Linghao; Yan, Lilong; Romano, Claudia
发表日期	2023
ISSN	0009-2541
EISSN	1872-6836
卷号	618
英文摘要	Granitic rocks derived by sequential partial melting are not well-documented worldwide. This paper provides another new important case in southern Tibet. The Yardoi gneiss dome within the Southern Tibet Rift System (STRS) consists of at least four suites of Miocene high-Sr/Y granites, formed at 20.4 Ma, 18.9 Ma, 17.7 Ma, and 17.1 Ma, respectively. Geochemical data indicate that they are Na-rich and peraluminous granites with high Sr/Y and La/Yb ratios. These granites show relatively radiogenic 87Sr/86Sr(t) (0.7091-0.7149) and unradiogenic epsilon Nd(t) (-11.1 to-7.7) isotopic signatures. As crystallization ages become younger, they are characterized by decreases in epsilon Nd(t) and Sr/Y but increases in 87Sr/86Sr(t) and Rb/Sr. Such temporal trends could be explained by sequential partial melting of first the mafic lower crustal rocks and then progressively shallower metasedi-mentary rocks. These findings together with literature-derived data, suggest that from north to south along the STRS, as extension proceeded with a heat source from the upwelling of asthenospheric mantle, sequential partial melting produced different Miocene magmatic rocks. This provides new insight into the mechanisms for the generation of geochemical and isotopic variations in spatially confined but temporally progressed granitic rocks.
关键词	Sequential melting High-Sr Y ratios Granites Extension Rift Southern Tibet
英文关键词	ND-ISOTOPE DISEQUILIBRIUM; EAST-WEST EXTENSION; PERALUMINOUS GRANITES; ZR/HF FRACTIONATION; LATE OLIGOCENE; ANATEXIS; OROGEN; LEUKOGRANITE; CONSTRAINTS; COLLISION
WOS研究方向	Geochemistry & Geophysics
WOS记录号	WOS:000921871100001
来源期刊	CHEMICAL GEOLOGY
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/282679
作者单位	China Geological Survey; Institute of Geology, Chinese Academy of Geological Sciences; Chinese Academy of Geological Sciences; China Geological Survey; Chinese Academy of Geological Sciences; National Research Center for Geoanalysis, Chinese Academy of Geological Sciences
推荐引用方式 GB/T 7714	Gao, Li-E,Zeng, Lingsen,Zhao, Linghao,et al. Sequential melting of deep crustal source rocks in a rift system: An example from southern Tibet[J],2023,618.
APA	Gao, Li-E,Zeng, Lingsen,Zhao, Linghao,Yan, Lilong,&Romano, Claudia.(2023).Sequential melting of deep crustal source rocks in a rift system: An example from southern Tibet.CHEMICAL GEOLOGY,618.
MLA	Gao, Li-E,et al."Sequential melting of deep crustal source rocks in a rift system: An example from southern Tibet".CHEMICAL GEOLOGY 618(2023).