Geochemistry and SHRIMP zircon U-Pb age of diabases in the Lajishankou ophiolitic melange, South Qilian terrane.

	Geochemistry and SHRIMP zircon U-Pb age of diabases in the Lajishankou ophiolitic melange, South Qilian terrane.
	Fu ChangLei 5; Yan Zhen ; Guo XianQing 1; Niu ManLan 2; Xia WenJing 2; Wang ZongQi 1; Li JiLiang 3
刊名	ACTA PETROLOGICA SINICA
	2014
卷号	30 期号:6 页码:1695-1706
关键词	Diabase Ocean island/Seamount Mid-ocean ridge Ophiolitic melange Lajishan Mountain
ISSN号	1000-0569
英文摘要	The Lajishankou ophiolitic melange, which is an important ingredient of the ophiolitic m lange between the Central and the South Qilian terranes, contains varities of Ethological units showing tectonic relationship between them. Diabases in this m lange occur as blocks and dykes respectively. The formers have SiO2, contents of 49. 80% similar to 50. 13%, MgO contents of 5.43% similar to 5. 64%, FeOT contents of 10. 96% similar to 11. 52% and relatively higher TiO2 contents of 2. 38% similar to 2. 62%; the laters have SiO2 contents of 43. 41% similar to 45. 74%, MgO contents of 9. 04% similar to 10. 64%, FeOT contents of 8.39% 9. 96% and low TiO, contents of 0. 89% similar to 1. 02%. They belong to tholeiitic rocks. The diabase blocks have high total REE contents ( 135. 4 x 10(-6) similar to 150. 9 x 10 (-6)) and ( La/Yb), ratios (3. 51 similar to 4. 03) with right-inclined REE patterns and enrichment in large ion lithophile elements ( including Rb, Ba, K, Sr) and high field strength elements ( including Th, Nb, Ta, Zr,, Hf, Ti), showing typical features of OIB. However, the diabase dykes have low total REE contents (36. 10 x 10(-6) similar to 43.72 x 10(-6)) and ( La/Yb), ratios ( 1. 12 similar to 1. 20) and flat REE patterns, indicating similar character of MORB. In addition, diabase blocks and dykes are lack of negative Nb, Ta and Ti anomalies. SHRIMP zircon U-Pb dating of diabase block yields a weighted mean Pb-206/U-238 age of 491. +/- 0 5. 1Ma, representing the age of crystallization. These characters suggest that the mafic diabases in the Lajishankou ophiolitic m lange were probably formed in ocean island/seamount and mid-ocean ridge environments, which were mixed with other lithological units during the northward subduction-accretion of the Proto-Tethys Ocean.
学科主题	变质岩岩石学
WOS关键词	TECTONIC IMPLICATIONS ; OCEANIC-CRUST ; ORIGIN ; CLASSIFICATION ; EMPLACEMENT ; ELEMENTS ; DIAGRAM ; BASALTS ; SERIES ; ZR
WOS研究方向	Geology
语种	中文
出版者	SCIENCE PRESS
WOS记录号	WOS:000338487400012
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/40481]
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, State Key Lab Continental Tecton & Dynam, Beijing 100037, Peoples R China 2.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China 3.Hefei Univ Technol, Dept Resources & Environm, Hefei 230009, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 5.中国地质科学院地质研究所
推荐引用方式 GB/T 7714	Fu ChangLei,Yan Zhen,Guo XianQing,et al. Geochemistry and SHRIMP zircon U-Pb age of diabases in the Lajishankou ophiolitic melange, South Qilian terrane.[J]. ACTA PETROLOGICA SINICA,2014,30(6):1695-1706.
APA	Fu ChangLei.,Yan Zhen.,Guo XianQing.,Niu ManLan.,Xia WenJing.,...&Li JiLiang.(2014).Geochemistry and SHRIMP zircon U-Pb age of diabases in the Lajishankou ophiolitic melange, South Qilian terrane..ACTA PETROLOGICA SINICA,30(6),1695-1706.
MLA	Fu ChangLei,et al."Geochemistry and SHRIMP zircon U-Pb age of diabases in the Lajishankou ophiolitic melange, South Qilian terrane.".ACTA PETROLOGICA SINICA 30.6(2014):1695-1706.