Age of terrigenous deposits of the Khingan Group in the Lesser Khingan terrane in the eastern part of the Central Asian fold belt

摘要

The results of investigations of gneissose hornblende granitoids, which intrude terrigenous deposits of the Murandav Formation of the Khingan Group and which were deformed together with them due to later structural transformations, are given. It is shown that by their geochemical properties these granitoids are comparable with granitoids of type I and are 535 +/- 6 Ma old (UaEuro'Pb method on zircons). The obtained data indicate that dikes of hornblende granites, which intrude terrigenous rocks of the Murandav Formation of the Khingan Group and are deformed together with them, were embedded at the Cambrian and Ediacaran transition. The assumption that terrigenous deposits of the Khingan Group (at least the Murandav and underlying Igincha formations) were accumulated in the Neoproterozoic is supported.