Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record

doi:10.1111/j.1440-1738.2008.00612.x

	Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record
	Zhang, Jin; Zhang, Hong-Fu; Ying, Ji-Feng; Tang, Yan-Jie; Niu, Li-Feng
刊名	ISLAND ARC
	2008-06-01
卷号	17 期号:2 页码:231-241
关键词	asthenospheric source contribution of subducted Pacific slab Late Cretaceous mafic dike Qingdao
ISSN号	1038-4871
DOI	10.1111/j.1440-1738.2008.00612.x
文献子类	Article
英文摘要	The occurrence of the Pishikou mafic dike in the Qingdao region, China provides important constraints on the origin of Late Cretaceous (86-78 Ma) mafic magmatism on the eastern North China craton. The Pishikou mafic dike is distributed in the Cretaceous Laoshan granitoid body, Qingdao region and contains peridotitic and granulitic xenoliths, xenocrysts, and megacrysts. Rocks from the Pishikou mafic dike are basanites and have low SiO(2) (< 42 wt%) and Al(2)O(3) (12.5 wt%) contents, and high MgO (> 8 wt%), total alkalis (Na(2)O + K(2)O > 4.8 wt%, Na(2)O/K(2)O > 1), TiO(2) (> 2.5 wt%), CaO (> 9 wt%) and P(2)O(5) (> 1 wt%). In trace element abundances, they are highly enriched in large ion lithophile elements (LILEs) and light rare-earth elements (LREEs) (Sigma REE = 339-403 ppm, (La/Yb)(N) = 39-42) without high field strength element (HFSE) depletion. These rocks have radiogenic Sr and Pb, and less radiogenic Nd isotopic compositions [((87)Sr/(86)Sr)(i) > 0.7059, epsilon Nd approximate to 2.7-3.8 ((206)Pb/(204)Pb)(i) approximate to 18.0 +/- 0.1]. The diagnostic elemental ratios, such as Nb/La, Nb/U, and Nb/Th, are compatible with those of mid-oceanic ridge basalts (MORBs) and oceanic island basalts (OIBs). Therefore, the Pishikou mafic dike has a geochemical feature completely different from those of the Early Cretaceous mafic dikes from the Qingdao region, but similar to those of back-arc basalts from the Japan Sea. This geochemical feature suggests that the Pishikou mafic dike was derived from an asthenosphere source, but contaminated by materials from the subducted Pacific slab. The discovery of this mafic dike thus provides a petrological evidence for the contribution of subducted Pacific slab to the Late Cretaceous magmatism in the Qingdao region of the eastern North China craton.
WOS关键词	LITHOSPHERIC MANTLE BENEATH ; EASTERN NORTH CHINA ; SINO-KOREAN CRATON ; ND-PB ISOTOPE ; CONTINENTAL-CRUST ; SHANDONG PROVINCE ; TRACE-ELEMENT ; TECTONIC IMPLICATIONS ; MESOZOIC BASALTS ; MAJOR-ELEMENT
WOS研究方向	Geology
语种	英语
出版者	WILEY-BLACKWELL
WOS记录号	WOS:000255464000005
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/69370]
专题	中国科学院地质与地球物理研究所
通讯作者	Zhang, Hong-Fu
作者单位	Chinese Acad Sci, State Key Lab Lithospher Evolut, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Jin,Zhang, Hong-Fu,Ying, Ji-Feng,et al. Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record[J]. ISLAND ARC,2008,17(2):231-241.
APA	Zhang, Jin,Zhang, Hong-Fu,Ying, Ji-Feng,Tang, Yan-Jie,&Niu, Li-Feng.(2008).Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record.ISLAND ARC,17(2),231-241.
MLA	Zhang, Jin,et al."Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region, China: A petrological record".ISLAND ARC 17.2(2008):231-241.