Buried Paleoproterozoic orogen of the East European Craton: Age and origin of the Vyatka terrane

We studied the composition, isotopic geochemistry and zircon U-Pb dating of Paleoproterozoic supracrustal rocks of the Uni Formation and granitoids of the Talitsky Complex of the Vyatka terrane located on the northeastern margin of the East European Craton. The obtained data were used to constrain the age, origin and tectonic setting of the Vyatka terrane, which is thought to be a part of the Paleoproterozoic Vyatka-Kama orogenic belt. Most of the gneisses and schists of the Uni Formation have greywacke protoliths, while metatuffites of andesite to dacite compositions are subordinate. All of these rocks have similar suprasubduction geochemical characteristics and highly radiogenic Nd isotopic compositions. The age of magmatic zircons from the felsic metatuffites is 2.08 Ga, and individual detrital grains from these rocks date back to ca. 2.12 Ga. Detrital zircons from the metasedimentary rocks have well-preserved crystals and multimodal U-Pb age distributions peaking at 2.08, 2.10, and 2.14 Ga. Some zircons from migmatized gneisses have 2.05-Ga-old rims, corresponding to the age of the Talitsky granitoids. The obtained data suggest that the Vyatka terrane could be considered an accretionary complex of the Vyatka-Kama orogen. The Uni Formation was formed by the accretion of sediments derived from an eroding Paleoproterozoic magmatic arcs (2.08-2.14 Ga). The completion of the accretionary tectonics was marked by the intrusion of the ca. 2.05-Ga-aged post-tectonic Talitsky granitoids. The Vyatka terrane accretionary complex contains chronologic counterparts of the West Sarmatian and Volga-Don orogens. This complements the model of a simultaneous amalgamation of Archean blocks of the Volgo-Sarmatia dating back to 2.2-2.0 Ga. Data from the Vyatka terrane confirm the model of the superposition of the East European and Siberian cratons in the Paleoproterozoic Columbia/Nuna supercontinent reconstruction. The Vyatka-Kama and Batomga belts may have been parts of a single extended Paleoproterozoic orogen that combined the Archean Volgo-Uralia and Aldan composite terranes. (c) 2023 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.