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Geochemical characteristics，Zircon U-Pb isotopic and the indicative geotectonic environment of the granitoids in Lupa terrain, Tanzania
HE Shengfei, LIU Xiaoyang, SUN Kai, XU Kangkang, GONG Penghui
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Geochemical characteristics，Zircon U-Pb isotopic and the indicative geotectonic environment of the granitoids in Lupa terrain, Tanzania
This paper is the result of rock geochemistry. [Objective] Lupa terrane is the second largest gold ore concentration area in Tanzania, and its formation age and genetic mechanism are controversy. [Methods] Through the analysis of zircon geochronology and geochemical characteristics of granite, the formation age and genetic mechanism of the Lupa terrane granite are determined. [Results] Zircon U-Pb geochronology studies indicate that there are two types of granites in the Lupa terrane: Neoarchean granites (2 663 ± 22 Ma～2 778 ± 13 Ma); Paleoproterozoic granite (1 944 ± 10 Ma～2 006 ± 10 Ma), and their geochemical characteristics are similar to those of I-type granite. The other basic rocks, carbonates and other rocks distributed within the earth represent the beginning of the breakup of the Rodinian super continent.[Conclusions] The geochemical characteristics of rocks indicate that the material source of non-A-type granite is not from the mantle, but the result of crustal remelting. The tectonic environment discrimination diagram of the granite shows that the sample projection falls in the volcanic arc granite, and the granite is concentrated in the continental granite area, away from the oceanic granite, oceanic basalt and gabbro area. The Neoarchean and Paleoproterozoic granites were formed in the continental margin arc.
Highlights：Through the study of zircon U-Pb chronology and rock geochemical characteristics, it is determined that the granite of Lupa terrane was formed in Paleoproterozoic, which is the result of crustal remelting, and the tectonic environment belongs to the continental margin arc.
Zircon U-Pb geochronology / geochemical characteristics / Lupa terrane / Tanzania {{custom_keyword}} /
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