XIAO Ling-ling, JIANG Zong-sheng

The Graduate School of the Chinese Academy of Sciences,Beijing 100049,China

Abstract:　　Amphibolites,one of the kinds of Precambrian basement rocks,are exposed in the south-middle Zanhuang Metamorphic Complex,central-south segment of the Trans-North China Orogen.These metamorphic rocks were carefully studied through field investigations and petrographical and geochemical analyses.It was found that protoliths of the Zanhuang amphibolites are calc-alkaline and tholeiitic rocks with a large range of ∑REE（41.38×10-6232.55×10-6） and weak LREE enrichment.The multi-element variation results showed that K,Rb and Ba were relatively concentrated,Nb and Ta were of evident depletion while Ti was of weak depletion.Geochemical characteristics and various relevant geochemical discrimination diagrams showed that the Zanhuang amphibolites were formed in volcanic arcs of continental margin similar to the current continental margin,which was resulted from the subduction between the Western Block and the Eastern Block.

Key words:　 North China Craton； Trans-North China Orogen； Zanhuang metamorphic complex； amphibolite； tectonic discrimination；

*Corresponding Author, E-Mail: xiaolingl05@mails.gucas.ac.cn

Bulletin of Mineralogy, Petrology and Geochemistry Vol. 29, No.4, 2010, page 339-347

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