Petrological and geochemical characteristics of the Wanganzhen complex and discussion on its genesis.

	Petrological and geochemical characteristics of the Wanganzhen complex and discussion on its genesis.
	Cai, JH ; Yan, GH ; Chang, ZS ; Wang, XF ; Shao, HX ; Chu, ZY
刊名	ACTA PETROLOGICA SINICA
	2003
卷号	19 期号:1 页码:81-92
关键词	petrological and geochemical characteristics genesis adakite-like rock Sr Nd and Pb isotopes Rb-Sr isochron age the Wanganzhen complex
ISSN号	1000-0569
文献子类	Article
英文摘要	The Wanganzhen complex is one of representative example of Taihang-Da Hinggan tectonomagmatic belt in eastern China, which has the largest scale and the most rock types. It consists of three-stage rocks. According to the major element, trace element, REE and Nd,Sr,Pb isotopic characteristics of the Wanganzhen complex reported in this paper, the main stage rocks (granodiorite, adamellite and few quartz diorite) have the similar petrological and geochemical characteristics to those of adakite with SiO(2)greater than or equal to58%, Al(2)O(3)greater than or equal to15 %, low Y content (4.20similar to12.68mug/g), high Sr content (518similar to861mug/g) and Sr/Y ratios (60.19similar to178.10), LREE enrichment with (La/Yb)(N)=34.06similar to76.91, HREE depletion with Yb=0. 44similar to1.00, no obviously Eu anomaly (Eu/Eu-* = 0.83similar to1.03), and relative depletion in the high field strength elements (such as Nb, Hf, Ti), I-Sr=0.7060, negative epsilon(Nd)(t) value(-16.29similar to14.27)and positive epsilon(Sr)(t) value (+23.7similar to+25.0), but obviously different from those of subduction-related adakites. These adakite-like rocks were most likely derived from the partial melting of basaltic lower crust in the thickened crust resulted from hot mantle material upwelling as several mushroom cloud and the thermally altered ground uplifting to the bottom of continental crust during late Jurassic period. But the early and the late stage ones belong to non-adakites. The early basic- to intermediate- instrusive rocks (hornblendite, gabbroite and diorite) are high Mg and Fe, LREE enrichment, Eu positive anomaly, enriched in compatible elements and low incompatible elements, I-Sr = 0.7056, epsilon(Nd)(t)=-16.72similar to10.92, which are the products of partial melting of subcontinental lithospheric enrich mantle and probably represent the underplating basaltic magma below the thickened continental crust during early Mesozoic era. The late alkaline intermediate- to acid-intrusive rocks (alkali-granite, quartz syenite and quartz monzonite) are characteristic of high K and Na, alkaline series and high SigmaREE, negative Eu anomaly, low Sr content, high Y and Yb, negative Sr anomaly, I-Sr = 0.7062, epsilon(Nd)(t)=-16.25,suggesting that the formation of adakite-like rocks of the main stage result in the lithospheric delamination and cause asthenosphere to upwell to the bottom of thinned continental crust, so the rocks of the late stage are formed by the partial melting of the materials in the crust-mantle transformation belt even in the middle crust. In this paper the Rb-Sr isochronal age of granodiorite (145.7 +/- 5.3Ma) is reported. Based on the Rb-Sr isochronal age of granite and granidiorite, the main body of the Wanganzhen complex was probably formed in late Jurassic period between 137.8Ma and 145.7Ma.
WOS关键词	SUBDUCTED LITHOSPHERE ; DACITE GENESIS ; CRUST ; MAGMAS ; CHINA ; ARC ; ADAKITES ; PERIOD ; ROCKS ; SR
WOS研究方向	Geology
语种	英语
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000181176400009
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/79045]
专题	中国科学院地质与地球物理研究所
通讯作者	Cai, JH
作者单位	1.Peking Univ, Fac Earth & Space Sci, Beijing 100871, Peoples R China 2.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China 3.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Cai, JH,Yan, GH,Chang, ZS,et al. Petrological and geochemical characteristics of the Wanganzhen complex and discussion on its genesis.[J]. ACTA PETROLOGICA SINICA,2003,19(1):81-92.
APA	Cai, JH,Yan, GH,Chang, ZS,Wang, XF,Shao, HX,&Chu, ZY.(2003).Petrological and geochemical characteristics of the Wanganzhen complex and discussion on its genesis..ACTA PETROLOGICA SINICA,19(1),81-92.
MLA	Cai, JH,et al."Petrological and geochemical characteristics of the Wanganzhen complex and discussion on its genesis.".ACTA PETROLOGICA SINICA 19.1(2003):81-92.