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      https://www.ias.ac.in/article/fulltext/jess/117/01/0001-0021

    • Keywords

       

      Large igneous provinces; basalts; trace elements; Geochemistry; Geodynamics; Mineralogy and Petrology.

    • Abstract

       

      Siberian Traps Large Igneous Province (STLIP) is one of the most voluminous volcanic provinces on Earth. The dominant erupted rocks are low-Ti basalts, which make up 80% by volume of the classical Noril’sk lava sequence. In the west Siberian basin and Maymecha-Kotuy area, the low- Ti basalts make up about 99% and 50% by volume, respectively. Dolerite sills in the Angara– Taseevskaya Syncline at the southeastern STLIP exhibit trace element patterns and Sr isotope ratios typical of the low-Ti basalts of the Noril’sk sequence. The most Mg-rich (MgO 9.5–11 wt%) and hence least differentiated dolerites are characterized by trace element patterns with Ta-Nb depletion, low Ce/Pb and high Sr/Pr. These trace element features are similar to water-saturated, mantle wedge-derived island arc basalts. These imply an important role of subduction fluid-derived trace elements in the source of melting beneath the Angara–Taseevskaya Syncline and other regions of the STLIP. Less magnesium rocks (MgO 3.8–6.1 wt%) with less prominent Ta-Nb depletion, higher Ce/Pb and lower Sr/Pr could be produced via olivine-plagioclase fractionation of primary high-magnesium melts.

    • Author Affiliations

       

      Alexei V Ivanov1 Elena I Demonterova1 Sergei V Rasskazov1 Tatyana A Yasnygina1

      1. Institute of the Earth’s Crust, Siberian Branch of Russian Academy of Sciences, Lermontov St. 128, Irkutsk 664 033, Russia.
    • Dates

       
  • Journal of Earth System Science | News

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