Geochemical features and tectonic significance of granitic gneiss of;Laguigangri metamorphic core complexes in southern Tibet

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	Geochemical features and tectonic significance of granitic gneiss of;Laguigangri metamorphic core complexes in southern Tibet
	Gu PingYang 3; He ShiPing ; Li RongShe ; Shi Chao ; Dong ZengChan ; Zha XianFeng ; Wu JiLian 1; Wang Yi
刊名	ACTA PETROLOGICA SINICA
	2013
卷号	29 期号:3 页码:756-768
关键词	Laguigangri metamorphic core complexes Granitic gneiss Geochemistry Ziron U-Pb dating Pan African orogenic events
ISSN号	1000-0569
英文摘要	The granitic gneiss of Laguigangri metamorphic core complexes in southern Tibet is characterized by high SiO2 and K2O, low Fe2O3, MgO and MnO, with alumina saturation index (A/CNK) of 1.07 similar to 1.19 and peraluminous minerals (such as muscovite and garnet). These features suggest that the granitic gneiss belongs to the high-K calci-alkaline peraluminous rocks. It is obvious that the chondrite-normalized REE shows right inclined patterns with obvious negative Eu abnormity, simultaneously, the primitive mantle normalized trace element spidergrams are characterized by enriched LILE (such as Rb, Th and U) and depleted HFSE (such as Sr and Nb), as well as evidently low contents of Ba and Hf, which are compatible with the characteristics of crustal derived S-type granites. The initial values of Sr-87/Sr-86(I-Sr) are in a range of 0.709 similar to 0.7306, the epsilon(Sr) (t) in a range of 80.65 similar to 379 and epsilon(Nd) (t = 514Ma) values of -7.13 similar to -8.97, without significant correlation between epsilon(Nd) (t) and I-Sr. The ratios of (Pb-206/Pb-204), (= 18.1062 similar to 18.8085), (Pb-207/Pb-204), (=15.7 similar to 15.8) and (Pb-208/Pb-204), (=37.5 similar to 38.2) also reveal crustal Pb isotopic features. Therefore, the granitic magma is originated from partially melting of clay and sandstone sedimentary rocks. With the U-Pb isotopic age of 514Ma, we believe that these rocks in Laguigangri formed during the transition period from syncollision (compressional) to post collision (extensional environment) in Pan African orogenic events in the north Himalayan. This magmatic activity may play an important role in formation of the Laguigangri metamorphic core complex.
学科主题	变质岩岩石学
WOS关键词	A-TYPE GRANITES ; JIANGXI PROVINCE ; CALC-ALKALINE ; PAN-AFRICAN ; ZIRCON ; AGES ; CHINA ; CONSTRAINTS ; DOME ; DISCRIMINATION ; PETROGENESIS
WOS研究方向	Geology
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000318829900002
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39909]
专题	中国地质调查局西安地质调查中心
作者单位	1.Xian Geol Survey Ctr, MLR, Key Lab Study Focused Magmatism & Giant Ore Depos, Xian 710054, Peoples R China. 2.Chang An Univ, Earth Sci & Resources Coll, Xian 710054, Peoples R China. 3.中国地质调查局西安地质调查中心
推荐引用方式 GB/T 7714	Gu PingYang,He ShiPing,Li RongShe,et al. Geochemical features and tectonic significance of granitic gneiss of;Laguigangri metamorphic core complexes in southern Tibet[J]. ACTA PETROLOGICA SINICA,2013,29(3):756-768.
APA	Gu PingYang.,He ShiPing.,Li RongShe.,Shi Chao.,Dong ZengChan.,...&Wang Yi.(2013).Geochemical features and tectonic significance of granitic gneiss of;Laguigangri metamorphic core complexes in southern Tibet.ACTA PETROLOGICA SINICA,29(3),756-768.
MLA	Gu PingYang,et al."Geochemical features and tectonic significance of granitic gneiss of;Laguigangri metamorphic core complexes in southern Tibet".ACTA PETROLOGICA SINICA 29.3(2013):756-768.