Title

79 M. V. Naumov, A. N. Larionov, V. L. Masaitis, M. S. Mashchak, S. V. Bogdanova, S. L. Presnyakov, E. N. Lepekhina

Isotopic age determination of shocked crystalline rocks from the central part of the East Eu-ropean Platform (Vorotilovo deep hole)

Results of the U-­Pb isotopic-­geochronologic investigation of zircon from shocked metamorphic and magmatic rocks composing the central uplift of the Puchezh-­Katunki impact structure are submitted. These results are the first representative geochronologic data for the crystalline basement of the central part of the East European platform. Two main events are revealed: 2540–2530 Ma – formation of the plagiogneiss­-amphibolite Late Archean sequence; 2020–1980 Ma – anatexis and granitization of the Archean Complex. The Jurassic meteorite impact influenced insignificantly to isotope system of primary zircons from crystalline rocks. Although the high-­level shock metamorphism (P > 35 GPa) causes some loss of radiogenic Pb from zircons, no full erasing of previous isotopic information is occurring. Thus, shocked zircon preserves a possibility to date ancient events.
Key words: East European Platform, U-­Pb dating on zircon, Puchezh-­Katunki impact structure, Vorotilovo deep hole, Early Precambrian, shock metamorphism.