Nd, Sr and Ph isotopic geochemistry of Paleo-Mesoproterozoic alkaline-rich intrusions from the northern part of the North China Craton: evidence of the lithospheric mantle enrichment.

	Nd, Sr and Ph isotopic geochemistry of Paleo-Mesoproterozoic alkaline-rich intrusions from the northern part of the North China Craton: evidence of the lithospheric mantle enrichment.
	Ren KangXu ; Yan GuoHan ; Cai JianHui ; Mu BaoLei ; Li FengTang ; Chu ZhuYin
刊名	ACTA PETROLOGICA SINICA
	2006-12-01
卷号	22 期号:12 页码:2933-2944
关键词	Paleo-mesoproterozoic North China Craton Alkaline-rich Intrusive Rocks Enriched Mantle Nd Sr And Pb Isotopes
ISSN号	1000-0569
文献子类	Article
英文摘要	The Paleo-Mesoproterozoic alkaline-rich intrusive rocks, mostly distributed in or near Yan-Liao triple-junction aulaeogen system and Liao-Ji aulacogen along the north part of the North China Craton (NCC), are composed of basic to intermediate rocks dominated with syenite suites with elevated contents of total alkali and potassium. In this paper a systematic geochemical study on Nd, Sr and Pb isotopic characteristics is presented. All the epsilon(Nd) ( 0 values of these alkali-rich rocks are negative and the range (-3.4 similar to -7.5) is in a small scale with an average of -4.8. These are consistent with the Nd isotopic characteristics of the Paleo-Mesoproterozoic basie-ultrabasic rocks in this area (epsilon(Nd) = -4 similar to -8), and also similar to the subalkaline extrusive in Yan-Liao aulacogen (E,, ( 1) = -4. 3 similar to -8. 9), which indicate that these alkaline-rich intusives are of enriched mantle origin. Their initial Sr-87/Sr-86 values have a relatively restricted range from 0. 7028 to 0. 7053, with an average of 0. 7041. The Pb-206/Ph-204 (14.500 similar to 15.701 14.968 average), (207)pb/Pb-204 (14.887 similar to 15.150, 14. 984 average) and Pb-208/Pb-204 (34.178 similar to 36.537, 35.057 average) ratios for K-feldspar show that most of these alkali-rich rocks have very low ratios except for those from the Liangtun-Kuangdonggou complex. On the epsilon(Nd) (t) - E-Sr (t) diagram, all the spots are near the mantle array line and close to the EMI endmember, which indicates that these rocks have a close connection to the materials from the EMI enriched mantle. Their lead-isotope evolution also illustrates that they have relation with mantle and lower crust. Furthermore, a simulative calculation of the two endmembers reveals that the average ratio of the lower crust contamination is about 14%. According to this study, the depletion degree of lithospheric mantle of NCC has become weak and weak since ca. 2. 5Ga, and the mantle enrichment appeared partly at about 2. 2Ca, all the lithospheric mantle was enriched at 1.85Ga and then became more and more enriched. It's also suggested that the lithospheric mantle enrichment of NNC is related to the crust materials carried by subduction at early time and the subsequent mantle fluid metasomatism.
WOS关键词	GEOLOGICAL IMPLICATION ; LIAONING PROVINCE ; COMPLEX ; ORIGIN ; PETROGENESIS ; CONSTRAINTS ; ROCKS ; FRACTIONATION ; CHRONOLOGY ; MOUNTAINS
WOS研究方向	Geology
语种	英语
出版者	SCIENCE CHINA PRESS
WOS记录号	WOS:000245660400011
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/66002]
专题	中国科学院地质与地球物理研究所
通讯作者	Ren KangXu
作者单位	1.Peking Univ, Sch Earth & Space Sci, Key Lab Orogen Belts & Crustal Evolut, Minist Educ, Beijing 100871, Peoples R China 2.PetroChina, Res Inst Explorat & Dev, Tarim Oilfield Co, Korla 841000, Peoples R China 3.Chinese Acad Geol Sci, Inst Mineral Resources, Beijing 100037, Peoples R China 4.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China
推荐引用方式 GB/T 7714	Ren KangXu,Yan GuoHan,Cai JianHui,et al. Nd, Sr and Ph isotopic geochemistry of Paleo-Mesoproterozoic alkaline-rich intrusions from the northern part of the North China Craton: evidence of the lithospheric mantle enrichment.[J]. ACTA PETROLOGICA SINICA,2006,22(12):2933-2944.
APA	Ren KangXu,Yan GuoHan,Cai JianHui,Mu BaoLei,Li FengTang,&Chu ZhuYin.(2006).Nd, Sr and Ph isotopic geochemistry of Paleo-Mesoproterozoic alkaline-rich intrusions from the northern part of the North China Craton: evidence of the lithospheric mantle enrichment..ACTA PETROLOGICA SINICA,22(12),2933-2944.
MLA	Ren KangXu,et al."Nd, Sr and Ph isotopic geochemistry of Paleo-Mesoproterozoic alkaline-rich intrusions from the northern part of the North China Craton: evidence of the lithospheric mantle enrichment.".ACTA PETROLOGICA SINICA 22.12(2006):2933-2944.