Geochemical characteristics, and tectonic setting of the Laohushan basalts, North Qilian Mountains

	Geochemical characteristics, and tectonic setting of the Laohushan basalts, North Qilian Mountains
	Qian, Q; Zhang, Q
刊名	ACTA GEOLOGICA SINICA-ENGLISH EDITION
	2001-12-01
卷号	75 期号:4 页码:452-457
关键词	North Qilian Mountains Laohushan basalts sediments geochemistry
ISSN号	1000-9515
文献子类	Article
英文摘要	The Ordovician Laohushan ophiolite, located in the eastern part of the North Qilian Mountains, is mainly composed of meta-peridotites, gabbros and basalts alternating with sediments. The sediments are mainly turbidites, including sandstones, siltstones, cherts etc. Major elements show that the basalts are subalkaline tholeiites and may be analogous to ocean-floor basalts. Except a few N-MORBs, most of the basalts are E-MORBs as indicated by incompatible element ratios such as (La/Ce)(N), La/Sm, Ce/Zr, Zr/Y and Zr/Nb. Negative Nb anomaly is common but negative Zr, Hf and Ti anomalies are quite rare. Based on the geochemical characteristics, it is suggested that the Laohushan basalts were formed in a back-are basin. epsilon (Nd) (t) of the basalts ranges between +3.0 and +8.9 and (Sr-87/Sr-86)(i) ranges between 0.7030 and 0.7060, indicating a depleted mantle source which was mixed with more or less enriched mantle components. Furthermore, the petrography of the sandstones and geochemistry of the cherts suggest that the sediments were deposited near a continental margin.
WOS研究方向	Geology
语种	英语
出版者	GEOLOGICAL SOC CHINA
WOS记录号	WOS:000172268600013
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/76653]
专题	中国科学院地质与地球物理研究所
通讯作者	Qian, Q
作者单位	CAS, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Qian, Q,Zhang, Q. Geochemical characteristics, and tectonic setting of the Laohushan basalts, North Qilian Mountains[J]. ACTA GEOLOGICA SINICA-ENGLISH EDITION,2001,75(4):452-457.
APA	Qian, Q,&Zhang, Q.(2001).Geochemical characteristics, and tectonic setting of the Laohushan basalts, North Qilian Mountains.ACTA GEOLOGICA SINICA-ENGLISH EDITION,75(4),452-457.
MLA	Qian, Q,et al."Geochemical characteristics, and tectonic setting of the Laohushan basalts, North Qilian Mountains".ACTA GEOLOGICA SINICA-ENGLISH EDITION 75.4(2001):452-457.