华北克拉通北部古-中元古代富碱侵入岩的Nd、Sr、Pb同位素地球化学:岩石圈地幔富集的证据

doi:10.3321/j.issn:1000-0569.2006.12.011

CORC > 北京大学 > 地球与空间科学学院

	华北克拉通北部古-中元古代富碱侵入岩的Nd、Sr、Pb同位素地球化学:岩石圈地幔富集的证据; 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.
	任康绪 ; 阎国翰 ; 蔡剑辉 ; 牟保磊 ; 李凤棠 ; 储著银
刊名	岩石学报
	2006
关键词	古-中元古代华北克拉通富碱侵入岩带 Nd、Sr、Ph 同位素富集地幔 Paleo-Mesoproterozoic North China Craton alkaline-rich intrusive rocks Nd,Sr and Pb isotopes enriched mantle
DOI	10.3321/j.issn:1000-0569.2006.12.011
英文摘要	华北克拉通北部古-中元古代富碱侵入岩主要分布在燕辽三叉裂堑系和辽吉拗拉谷中及附近,为一套高碱高钾的基性-中性岩,以正长岩类为主。本文通过开展系统的 Nd、Sr、Pb 同位素研究,发现所有岩体岩石均以高负ε_(Nd)(t)为特征,ε_(Nd)(t)=-3.4～-7.5,平均值为～4.8,这与研究区古-中元古代基性-超基性岩石的 Nd 同位素特征(ε_(Nd)(t)=-4～-8) 一致,与燕辽裂堑系发育的偏碱性火山岩 Nd 同位素特征(ε_(Nd)(t)=-4.3～-8.9)也比较相似,表明它们的物质来源相似,都与富集地幔有关。Sr 同位素初始比值(~(87)St/~(86)Sr)_i比较低,主要...; 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.; http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000245660400011&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701 ; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 3; 12; 2933-2944; 22
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/48929]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	任康绪,阎国翰,蔡剑辉,等. 华北克拉通北部古-中元古代富碱侵入岩的Nd、Sr、Pb同位素地球化学:岩石圈地幔富集的证据, 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]. 岩石学报,2006.
APA	任康绪,阎国翰,蔡剑辉,牟保磊,李凤棠,&储著银.(2006).华北克拉通北部古-中元古代富碱侵入岩的Nd、Sr、Pb同位素地球化学:岩石圈地幔富集的证据.岩石学报.
MLA	任康绪,et al."华北克拉通北部古-中元古代富碱侵入岩的Nd、Sr、Pb同位素地球化学:岩石圈地幔富集的证据".岩石学报 (2006).