Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,;North China Craton and its geological implications

doi:10.1016/j.jseaes.2012.09.031

	Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,;North China Craton and its geological implications
	Yang, Chonghui 3; Du, Lilin ; Ren, Liudong ; Song, Huixia ; Wan, Yusheng 1; Xie, Hangqiang 1; Geng, Yuansheng
刊名	JOURNAL OF ASIAN EARTH SCIENCES
	2013
卷号	72;SI SI 页码:178-189
关键词	TTG gneisses ca. 2.7 Ga Geochemistry Zanhuang Complex North China Craton
ISSN号	1367-9120
DOI	10.1016/j.jseaes.2012.09.031
英文摘要	Through detailed studies we have delineated a suite of banded ITG gneisses from the Zanhuang Complex. The protolith of the gneisses, predominantly tonalite, has undergone intensive metamorphism, deformation and anatexis and in a banded structure is intimately associated with melanocratic dioritic gneiss and leucocratic trondhjemitic veins. SHRIMP Zircon U-Pb data show that the tonalite was formed ca. 2692 +/- 12 Ma ago. The tonalitic gneiss has the features of high SiO2 (67.76-73.31%), high Al2O3 (14.38-15.83%), rich in Na2O (4.48-5.07%) and poor in K2O (0.77-1.93%). The gneiss is strongly fractioned in REE ((La/Yb)(N) = 12.02-24.65) and shows a weak positive Eu anomaly (Eu/Eu* = 1.05-1.64). It has high contents of Ba (199-588 ppm) and Sr (200-408 ppm), low contents of Yb (0.32-1.00 ppm) and Y (3.41-10.3 ppm) with high Sr/Y ratios (21.77-96.77) and depletion in HFSE Nb, Ta and Ti. These characteristics are similar to those of the high-Si adakitic rocks. The melanocratic dioritic gneiss has low SiO2 (59.81%), high MgO (6.34%), high Al2O3 (14.02%) contents, rich in Na2O (3.7%) and poor in K2O (1.79%), with high Mg index (Mg-# = 67). REE and trace elements are on the whole similar to that of the tonalitic gneiss, but compatible element abundances V (116 ppm), Cr (249 ppm), Co (37 ppm) and Ni (179 ppm) are higher. The leucocratic felsic bands (approximating trondhjemite in composition) have major oxides similar to that of the TTG gneisses but the REE and compatible elements are extremely low, which are indicative of the products of anatexis. The tonalitic gneiss has positive epsilon(Nd)(t) (2.37-3.29) and low initial Sr (0.69719-0.70068) values with depleted mantle Nd model age of ca. 2.8 Ga, suggesting its generation from partial melting of mantle-derived juvenile crust. The dioritic gneiss was also derived from subduction environment, but has undergone significant metasomatism of mantle wedge. The delineation of the ca. 2.7 Ga TFG gneisses in the Zanhuang Complex further proves that the North China Craton experienced large-scale continental crustal accretion in early Neoarchean, and gives new constraints on the subdivision of the early blocks and greenstone belts of the craton. (C) 2012 Elsevier Ltd. All rights reserved.
学科主题	变质岩岩石学
WOS关键词	ARCHEAN CRUSTAL EVOLUTION ; PB ZIRCON GEOCHRONOLOGY ; SOUTHERN WEST ; GREENLAND ; U-PB ; SUPERIOR PROVINCE ; CONTINENTAL GROWTH ; GREENSTONE-BELT ; ISOTOPIC CONSTRAINTS ; METAMORPHIC EVENTS ; TECTONIC EVOLUTION
WOS研究方向	Geology
语种	英语
出版者	PERGAMON-ELSEVIER SCIENCE LTD
WOS记录号	WOS:000321404900015
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40082]
专题	中国地质科学院地质研究所
作者单位	1.Chinese Acad Geol Sci, Inst Geol, Beijing 100037, Peoples R China. 2.Beijing SHRIMP Ctr, Beijing 100037, Peoples R China. 3.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Yang, Chonghui,Du, Lilin,Ren, Liudong,et al. Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,;North China Craton and its geological implications[J]. JOURNAL OF ASIAN EARTH SCIENCES,2013,72;SI SI:178-189.
APA	Yang, Chonghui.,Du, Lilin.,Ren, Liudong.,Song, Huixia.,Wan, Yusheng.,...&Geng, Yuansheng.(2013).Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,;North China Craton and its geological implications.JOURNAL OF ASIAN EARTH SCIENCES,72;SI SI,178-189.
MLA	Yang, Chonghui,et al."Delineation of the ca. 2.7 Ga TTG gneisses in the Zanhuang Complex,;North China Craton and its geological implications".JOURNAL OF ASIAN EARTH SCIENCES 72;SI SI(2013):178-189.