The Mesoproterozoic mantle plume beneath the northern part of the Siberian craton |
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| Institution: | 1. Institute of the Earth’s Crust, Siberian Branch of the RAS, ul. Lermontova 128, Irkutsk, 664033, Russia;2. Australian Research Council Centre of Excellence for Core to Crust Fluid Systems (CCFS) and the Institute for Geoscience Research (TIGeR), Department of Applied Geology, Curtin University, GPO Box U1987, Perth, WA 6845, Australia;3. School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia;4. Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada;5. Tomsk State University, pr. Lenina 36, Tomsk, 634050, Russia;6. Ernst Geosciences, 43 Margrave Ave., Ottawa, ON K1T 3Y2, Canada;1. Department of Earth Sciences, University of Toronto, Toronto, ON, Canada;2. Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, Scotland, United Kingdom;1. Department of Geosciences, University of Montana, 32 Campus Drive #1296, Missoula, MT 59812-1296, USA;2. Department of Geosciences, Boise State University, 1910 University Drive, Boise, ID 83725-1535, USA;3. School of the Environment, Washington State University, Pullman, WA 99164-2812, USA;1. Department of Geoscience, Aarhus University, Høegh-Guldbergs Gade 2, 8000 Aarhus C, Denmark;2. Ruhr-Universität Bochum, Institut für Geologie, Mineralogie und Geophysik, D-44870 Bochum, Germany |
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| Abstract: | The study of the Mesoproterozoic (1473 ± 24 Ma) dolerites of the Olenek uplift of the Siberian craton basement has shown their petrologic and geochemical similarity to typical OIB produced with participation of a mantle plume. The dolerites are characterized by variations in the geochemical composition explained by different degrees of melting of the same source. A conclusion is drawn that the parental melts of the rocks were slightly modified by crustal contamination, as evidenced from their Nd isotope composition (£Nd(T) = + 0.6 to ? 0.8) and the presence of inherited zircons of four ages (2564, 2111, 2053, and 1865 Ma). Since the Siberian craton in the structure of the Nuna supercontinent (Columbia) was located relatively close to the Baltic continent and the Congo and Sao Francisco cratons, we assume that the Early Mesoproterozoic mafic intrusions (1500–1470 Ma) of all these cratons belong to the same large igneous province (LIP). The province formation was related to the activity of superplume (or mantle hot field), which supplied mantle matter to the lithosphere basement. The superplume core was probably located beneath the northern part of the Siberian craton, where basites are compositionally most similar to the primary mantle source. |
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