Geochemical characteristics of the Changhai granitic gneisses in;Southeast Liaoning Province, NE China: Implications for its protolith;property and formed tectonic setting

	Geochemical characteristics of the Changhai granitic gneisses in;Southeast Liaoning Province, NE China: Implications for its protolith;property and formed tectonic setting
	Meng En; Liu FuLai; Liu JianHui; Shi JianRong
刊名	ACTA PETROLOGICA SINICA
	2012
卷号	28 期号:9 页码:2793-2806
关键词	Granitic gneisses Geochemistry Sodium-rich Potassium-rich Protolith petrogenesis Jiao-Liao-Ji Belt Changhai
ISSN号	022HC
英文摘要	In this paper, we performed systematically petrological and geochemical studies on the granitic gneisses near the Changhai Town in the southeastern Liaoning Province. Our data placed constraints on their protolith and tectonic setting. The results showed that these granitic gneisses could be divided into two types, (sodium) Na-rich and (potassium) K-rich granitic gneisses. The former are mainly composed of biotite monzogneisses and biotite granodioritic gneisses, and their mineral compositions chiefly include plagioclase, quartz, biotite and K-feldspar, etc. The latter consist of granitic, monogranitic and mylonitic granitic geisses, the mineral compositions of which are mainly composed of K-feldspar, plagioclase, quartz and minor muscovite and biotite. Geochemical analyses indicate that the Na-rich granitic gneisses are characterized by high contents of SiO2, Na2O and Al2O3, enrichment in light rare earth elements (LREEs) and large ion lithophile elements (LILEs), strong depletion in heavy rare earth elements (HREEs) and high field-strength elements (HFSEs), relative depletion in Ba and weak negative Eu anomaly. On the other hand, the K-rich granitic gneisses are peraluminous and show geochemical features of high contents of SiO2 and K2O, enrichments in LREEs and LILEs, and depletion in HREEs and HFSEs. However, compared to the Na-rich ones, the K-rich granitic gneisses exhibit moderate negative Eu anomaly, relatively weaker REEs fractionation and stronger depletion in HFSEs and Ba. These features suggest that the Na-rich granitic gneisses could be derived from the partial melting of intermediate-acid crustal materials, with some basaltic material involved in the source and their protolith could be the granodiorite formed at an active continental margin The formation of these Na-rich granitic gneisses could be related to the subduction of the pre-existent oceanic basin beneath the Nangrim Massif (or Jiao-Liao Massif). On the other way, the Na-rich granitic gneisses could originate by partial melting of the crust and their protolith could be alkaline granites in a collisional tectonic setting after subtraction and closure of the previous oceanic crust.
学科主题	变质岩岩石学
WOS关键词	TRONDHJEMITE-GRANODIORITE TTG ; PB ZIRCON GEOCHRONOLOGY ; NORTH CHINA ; U-PB ; CRUSTAL EVOLUTION ; EASTERN BLOCK ; JI BELT ; BASEMENT ROCKS ; LIAOHE-GROUP ; GEOLOGICAL SIGNIFICANCE
WOS研究方向	Geology
语种	中文
WOS记录号	WOS:000309947500010
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39663]
专题	中国地质科学院地质研究所
作者单位	Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China.
推荐引用方式 GB/T 7714	Meng En,Liu FuLai,Liu JianHui,et al. Geochemical characteristics of the Changhai granitic gneisses in;Southeast Liaoning Province, NE China: Implications for its protolith;property and formed tectonic setting[J]. ACTA PETROLOGICA SINICA,2012,28(9):2793-2806.
APA	Meng En,Liu FuLai,Liu JianHui,&Shi JianRong.(2012).Geochemical characteristics of the Changhai granitic gneisses in;Southeast Liaoning Province, NE China: Implications for its protolith;property and formed tectonic setting.ACTA PETROLOGICA SINICA,28(9),2793-2806.
MLA	Meng En,et al."Geochemical characteristics of the Changhai granitic gneisses in;Southeast Liaoning Province, NE China: Implications for its protolith;property and formed tectonic setting".ACTA PETROLOGICA SINICA 28.9(2012):2793-2806.