Scientific publications

The results of the study of Paleoproterozoic intrusive rocks from the eastern Zaonezhsky Peninsula are reported. The petrographic and geochemical description of the rocks is presented and the results of the U.Pb dating of the zircons extracted from them are reported. The age of quartz dolerites from the eastern Zaonezhsky Peninsula (Lebeshchina area) is estimated at 1956 ± 5 Ma. The dolerites were shown to be petrogeochemically similar to those of the Onega structure and are probably indicative of a large-scale episode of magmatic activity. The dolerites we dated had less deep sources of generation of the primary melts, above the stability field of garnet, than the preceding Mg.rich Suisari basic rocks. A succession of the processes of melting of the mantle sources that occurred at different depths and at quite close times has been established for the Ludicovian. It presumably reflects one geodynamic event.