Isotope-Geochemical Features of the Migmatites of the Taratash Metamorphic Complex (Southern Urals).

The article presents data on migmatites of the Taratash metamorphic complex, Southern Urals. We studied the Sm-Nd isotopic system in ultrametamorphic processes leading to partial melting of a protolith and migmatization. The Sm-Nd isotopic system of the rocks indicates the contribution of Paleoarchean protolith (TNd2 = 3.2–3.6 Ga) to the Taratash metamorphic complex, with the predominance of the crustal component (ɛNd(T) from −7.6 to −10.5). Based on morphology, U-Pb isotopic age, and Th/U-ratio, zircon found in melanosome and leucosome of the migmatites is subdivided into two generations. The main stage of migmatization occurred within 2.1–1.8 Ga ago and was triggered by granulite metamorphism at 2.06 Ga. Zircon grains of this stage have the low uranium concentration (213–469 ppm) at typical thorium concentration (180–631 ppm), Th/U = 0.8–1.7. [ABSTRACT FROM AUTHOR]