STABILITY OF ZIRCON IN THE SYSTEM MgO-SiO2-H2O AT 2.5 GPa
N.L. Dobretsov1,2, A.I. Chepurov3, V.M. Sonin3, E.I. Zhimulev3
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, 3, pr. Koptyuga, Novosibirsk, 630090, Russia 2Novosibirsk State University, 2, ul. Pirogova, Novosibirsk, 630090, Russia 3S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, 3, pr. Koptyuga, Novosibirsk, 630090, Russia
Keywords: Zircon, baddeleyite, peridotitic mineral assemblage, high pressure, high temperature
Abstract
We report preliminary experimental data on the interaction of zircon with the peridotitic assemblage olivine + serpentine at 2.5 GPa and 1400 °C. In these conditions, zircon is unstable and decomposes with the formation of baddeleyite. Therefore, it is unlikely that zircon could survive in ultramafic rocks for a long time in the presence of a fluid phase at high temperatures. Thus, rigorous constraints on boundary conditions are required for the use of zircon in the dating of high-temperature geologic processes.
DOI: 10.15372/RGG2019043
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