Geologicheskii Vestnik

The paper presents new data on the discoveries of “ancient” zircons in igneous rocks of the Shatak complex. Based on the study of morphology of the crystals, it was shown that the zircons from the basaltoids of the complex belong to igneous type, modified by secondary processes. It is concluded that the “ancient” zircons are xenogenic material of the Archean-Paleoproterozoic granite-gneiss substrate, which melted during contamination as a result of the AFC process, which was characterized by a fractionation of liquidus phases (olivine±clinopyroxene) and accumulation of a fluid phase in the roofing section of the chamber on the one hand, and the assimilation of host rocks on the other.

South Ural, basalts, zircons, U-Pb dating, magmatic melt, fractionation, assimilation

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