摘要
冀北退变榴辉岩的全岩Pb同位素比值(206Pb/204Pb)i,(207Pb/204Pb)i和(208Pb/204Pb)i分别为17.324～17.460,15.412～15.464和37.216～37.380;Δ(207Pb/204Pb)i和Δ(208Pb/204Pb)i相应为4.026～8.034和61.285～69.928,表明岩浆源区为具DUPAL异常的富集地幔,可能为亏损的软流圈地幔(DMM)与第一类富集地幔端元(EMI)相混合的异常地幔,指示该区早先存在有一次板块消减事件。这对正确认识华北古陆块北缘的大地构造格局和演化具有十分重要的意义。
The whole rock Pb isotopic compositions of the retrograded eclogites from the northern Hebei are reported in this paper. Their (()^(206)Pb/()^(204)Pb)_i, (()^(207)Pb/()^(204)Pb)_i and (()^(208)Pb/()^(204)Pb)_i ratios are 17.324^(17.460), 15.412~15.464 and 37.216~37.380, respectively. In addition, Δ(()^(207)Pb/()^(204)Pb)_i are 4.026^(8.034) and Δ(()^(208)Pb/()^(204)Pb)_i are 61.285~69.928. Pb isotope geochemistry indicates that the magma source is an abnormal mantle with DUPAL abnormality. This mantle is a mixture the the depleted asthenosphere mantle(DMM) and the first enriched mantle(EM I) in plate subduction zone. The results provide (important) data for the recognition of tectonic framework and evolution of the northern margin of the North China craton.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第2期125-128,共4页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
中国科学院知识创新工程项目(KZCX1-07)
国家自然科学基金重点项目(40234050)
关键词
PB同位素
退变榴辉岩
冀北
华北古陆块
Pb isotope
retrograded eclogite
northern Hebei
North China craton
