We report new data on the petrogenesis, tectonic settings, thermodynamic conditions, metamorphism and protolith ages for compositionally contrasting rocks of the Garevka metamorphic complex, obtained from the results of mineralogical-petrological, geochemical, and isotope-geochronological studies. Zircon SHRIMP U–Pb analyses coupled with 40Ar-39Ar dating constrain the timing of two new pulses of Neoproterozoic endogenous activity at the western margin of the Siberian Craton, associated with Grenville (930–900 Ma) and (880–845 Ma) post-Grenville Valhalla (880–845 Ma) accretion-and-collision processes.