Neoproterozoic Bimodal Intrusive Complex in the Southwestern Tarim Block, Northwest China: Age, Geochemistry, and Implications for the Rifting of Rodinia
MetadataShow full item record
We report here the first SHRIMP U-Pb zircon ages and bulk-rock geochemistry for a Neoproterozoicbimodal intrusive complex in the Tarim block and discuss the tectonic implications. The Kudiigneous complex (KIC) crystallized at 783 10 Ma. Granite and gabbro comingled, indicating thatthe intrusions were coeval. The granite displays: high total alkalis (Na2O + K2O = 8?11 wt%); highabundances of Zr, Nb, Y, and total REE; and strong LREE enrichment [(La/Yb)N = 9?59] with asignificant negative Eu anomaly (dEu = 0.17?0.44), characteristic of A-type granites. Furthermore,samples of the granite have homogeneous positive eNd(T) values of 1.4 to 2.1 and MesoproterozoicNd modal ages (~1.3 Ga). We thus interpret the granite as probably generated by partial melting ofthe regional Mesoproterozoic arc and/or back-arc crust. The KIC gabbro is geochemically similar tointraplate alkaline basalts, with trace elements and isotope compositions indicating an OIB-typemagma source, variably contaminated by continental crust. Field observations, petrology, andgeochemistry indicate that the KIC was a bimodal alkaline complex formed by mixing of these twomagma types of different origins in a continental rift, possibly related to a mantle superplumebeneath the Rodinian supercontinent.
Showing items related by title, author, creator and subject.
Gladkochub, D.; Donskaya, T.; Sklyarov, E.; Kotov, A.; Vladykin, N.; Pisarevskiy, Sergei; Larin, A.; Salnikova, E.; Saveleva, V.; Sharygin, V.; Starikova, A.; Tolmacheva, E.; Velikoslavinsky, S.; Mazukabzov, A.; Bazarova, E.; Kovach, V.; Zagornaya, N.; Alymova, N.; Khromova, E. (2017)© 2017 Elsevier B.V. We report new geological, mineralogical, geochemical and geochronological data about the Katugin Ta-Nb-Y-Zr (REE) deposit, which is located in the Kalar Ridge of Eastern Siberia (the southern part of ...
Korhonen, Fawna; Saito, S.; Brown, M.; Siddoway, C. (2010)The Fosdick migmatite–granite complex in West Antarctica records evidence for crustal melting during two periods of tectonism along the East Gondwana margin. Initial high-temperature metamorphism in the Devonian–Carboniferous ...
Magma-driven, high-grade metamorphism in the Sveconorwegian Province, southwest Norway, during the terminal stages of Fennoscandian Shield evolutionSlagstad, T.; Roberts, N.; Coint, N.; Høy, I.; Sauer, S.; Kirkland, Chris; Marker, M.; Røhr, T.; Henderson, I.; Stormoen, M.; Skår, �.; Sørensen, B.; Bybee, G. (2018)Â© 2018 The Authors. Recently it has been argued that the Sveconorwegian orogeny in southwest Fennoscandia comprised a series of accretionary events between 1140 and 920 Ma, behind a long-lived, active continental margin ...