Vysotskyi O. Geochronology of rocks of the Osnitsky block

The dissertation is devoted to the results of isotope - geochemical and radiogeochrological researches of rocks of Osnitsky block. For the first time, data were obtained on the age of gabbro, diorite and granodiorite of the Osnitsky complex, both for zircon and titanite. For both titanites and zircons from the plutonic rocks of the Osnitsky block, almost the same age values were obtained within the margin of error - 1.99-1.96 Ga. It is determined that the Klesiv series was formed in the age range of 2.02 -1.97 Ga. The age of the leptites of the Klesiv series is 2.02 Ga, which corresponds to the age of the beginning of volcanic activity. The age of zircon from quartz porphyries is 1.97 Ga, that corresponds to the upper limit of the volcanic processes that led to the formation of rocks of the Klesiv series. According to radiogeochronological data (LA-ICP-MS method), the affiliation of pre-Osnitsky plagiogranites to the Sheremetyvsky complex (the age of the central parts of zircon crystals is 2.16 Ga) is substantiated. The source of formation of magmatic melts using primary strontium ratios (87Sr/86Sr) in apatites and plagioclases was determined, and isotopic Sm-Nd dating of gross samples of rocks of the block.