Late Riphean Sedimentation in the Central Russian Aulacogen

Result of the analysis of combined structural, facies, mineralogical, and micropaleontological data suggest that the formation of the Central Russian Aulacogen was related to the evolution of a major strike-slip system in the Late Riphean on the Russian Plate. The strike-slip system led to the formation of parageneticaly interrelated structures: central anticlinal uplift framed by two troughs (structurally isolated echelon of lake-type sedimentary basins). The structural pattern of Late Riphean riftogenesis was responsible for the isolation of the sedimentation system. The variable intensity of extension at opposite flanks of the aulacogen is reflected in the fanlike form of the present-day structure and composition of sedimentary complexes, particularly the presence of red-colored molasse in the widest (southwestern) part of the study region. The growth of the central uplift is inferred from the enrichment of heavy fraction in epidote from blastomylonites derived from the lithostructural framing (rocks of the tectonic melange).