High-pressure melting of metapelite and the formation of Ca-rich granitic melts in the Namche Barwa Massif, southern Tibet

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	High-pressure melting of metapelite and the formation of Ca-rich granitic melts in the Namche Barwa Massif, southern Tibet
	Zeng, LS (Zeng, Lingsen)5; Gao, LE (Gao, Li-E); Dong, CY (Dong, Chunyan); Tang, SH (Tang, Suohan)
刊名	GONDWANA RESEARCH
	2012
卷号	21 期号:1 页码:138-151
关键词	Metapelite Partial melting Migmatite Granulite facies metamorphism Geochemistry Zircon geochronology Tibet
ISSN号	1342-937X
英文摘要	A detailed geochemical and geochronological study of anatectic migmatites from the Namche Barwa Massif (NBM), southern Tibet, has been carried out to place important constraints on the thermal and tectonic evolution of the eastern Himalayan syntaxis. SHRIMP zircon U/Pb dating indicates that the granulite-facies metapelite underwent metamorphism at 21.8 +/- 0.7 Ma and 24.5 +/- 0.7 Ma, respectively. The latter is similar to the timing of partial melting and the formation of Ca-rich leucosomes at similar to 24-25 Ma. These leucosomes are characterized by (1) high CaO, Na2O, and Na/K ratios (2) radiogenic Sr (Sr-87/Sr-86(t) = 0.7407-0.7904) but unradiogenic Nd (epsilon(Nd)(t) = -7.0 to -21.2) isotope compositions (3) depleted HFSE, and (3) variable but depleted HREE relative to their host pelites. Some of the leucosomes show large degrees of Nd isotopic disequilibrium, up to 10 epsilon units with respect to their hosts. These high CaO and Na2O leucosomes were derived from fluxing melting of metapelite at high pressures. A similar process could have operated during the formation of the Himalayan leucogranites and contributes to the heterogeneities in such granites. (C) 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.
学科主题	沉积学与沉积岩
WOS关键词	EASTERN HIMALAYAN SYNTAXIS ; GRANULITE-FACIES METAMORPHISM ; ND-ISOTOPE DISEQUILIBRIUM ; YARDOI GNEISS DOME ; CRUSTAL ANATEXIS ; TECTONIC EVOLUTION ; NANGA-PARBAT ; PETROLOGICAL CONSTRAINTS ; GEOCHEMICAL CONSTRAINTS ; GEOLOGICAL IMPLICATIONS
WOS研究方向	Geology
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000300204400011
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39665]
专题	中国地质调查局
作者单位	1.[Zeng, Lingsen 2.Gao, Li-E 3.Dong, Chunyan 4.Chinese Acad Geol Sci, Inst Geol, State Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China 5.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Zeng, LS ,Gao, LE ,Dong, CY ,et al. High-pressure melting of metapelite and the formation of Ca-rich granitic melts in the Namche Barwa Massif, southern Tibet[J]. GONDWANA RESEARCH,2012,21(1):138-151.
APA	Zeng, LS ,Gao, LE ,Dong, CY ,&Tang, SH .(2012).High-pressure melting of metapelite and the formation of Ca-rich granitic melts in the Namche Barwa Massif, southern Tibet.GONDWANA RESEARCH,21(1),138-151.
MLA	Zeng, LS ,et al."High-pressure melting of metapelite and the formation of Ca-rich granitic melts in the Namche Barwa Massif, southern Tibet".GONDWANA RESEARCH 21.1(2012):138-151.