Geochemical and Nd isotopic evidence for the genesis of the gneisses from the southern Shandong Peninsula, Sulu orogen

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	Geochemical and Nd isotopic evidence for the genesis of the gneisses from the southern Shandong Peninsula, Sulu orogen
	Xue, HM (Xue HuaiMin); Liu, FL (Liu FuLai); Meng, FC (Meng FanCong)
刊名	ACTA PETROLOGICA SINICA
	2007
卷号	23 期号:12 页码:3239-3248
关键词	granitic gneiss plagiogneiss geochemistry neoproterozoic southern Shandong Peninsula
ISSN号	1000-0569
英文摘要	The gneisses outcroped in the southern part of the Shandong peninsula, Sulu orogen include three types biotite-plagiogneisses, monzogranitic gneiss and A-type granitic gneiss, their protoliths are all belong to igneous rocks based on geochemical discriminations. The three types of gneisses have different geochemical characteristics, which reflecting different evolutionary processes of their protoliths. Compared to other gneisses, the biotite-plagiogneisses are characterized by feeble negative to large positive Eu anomalies (delta Eu = 0.60 similar to 1.45), significant positive Ba anomalies, no negative Sr anomalies, which is characteristic of rocks that have high model concentrations of plagioclase. The bulk geochemical features make them similar to the acidic end-member (rhyolitic pyroclastic rocks) of the Neoproterozoic bio-modal volcanic rocks that outcrop along the northern margin of the Yangtze Craton, implying that the gneisses may be metamorphosed from the rhyolitic pyroclastic rocks; The monzogranitic gneisses are characterized by strong fractionation between LREE and HREE (La-N/Yb-N = 6.3 similar to 17.2) which similar to the biotite-plagiogneisses, while strong negative Eu anomaly (delta Eu = 0.27 similar to 0.54), strong negative Sr anomalies and feeble negative Ba anomalies which obvious different to the biotite-plagiogneisses; The A-type granitic gneisses have similar REE and multielement spidergram patterns with the monzogranitic gneisses, while have relatively feeble negative Nb and Ta anomalies compared to the monzogranitic gneisses. The epsilon(Nd) (t) values are homogeneous among these three types of gneisses, which may reflecting genesis relationship among their protoliths. Their model ages of Nd isotope (T-DM) are focused at about 2.0Ga, implying that they formed by partial melting of homogeneous Paleoproterozoic rocks in the Neoproterozoic. It can be considered that the protoliths of the biotite-plagiogneisses and the monzogranitic gneisses are comagmatic and out-of-phases, and the A-type granitoid may formed by remelting of dehydrated charnockitic lower crust after large I-type granitic magma formed.
学科主题	变质岩岩石学
WOS关键词	ZIRCON U-PB ; SCIENTIFIC DRILLING PROJECT ; METAMORPHIC ROCKS ; TECTONIC IMPLICATIONS ; GRANITIC GNEISSES ; DABIE MOUNTAINS ; IGNEOUS ROCKS ; ELEMENT ; CHINA ; AGES
WOS研究方向	Geology
语种	中文
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000254582000016
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/38460]
专题	中国地质调查局
作者单位	Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China
推荐引用方式 GB/T 7714	Xue, HM ,Liu, FL ,Meng, FC . Geochemical and Nd isotopic evidence for the genesis of the gneisses from the southern Shandong Peninsula, Sulu orogen[J]. ACTA PETROLOGICA SINICA,2007,23(12):3239-3248.
APA	Xue, HM ,Liu, FL ,&Meng, FC .(2007).Geochemical and Nd isotopic evidence for the genesis of the gneisses from the southern Shandong Peninsula, Sulu orogen.ACTA PETROLOGICA SINICA,23(12),3239-3248.
MLA	Xue, HM ,et al."Geochemical and Nd isotopic evidence for the genesis of the gneisses from the southern Shandong Peninsula, Sulu orogen".ACTA PETROLOGICA SINICA 23.12(2007):3239-3248.