Bezvinniy V. Particularities of geological structure, composition supracrustal and ultrametamorphic formations of Rosinsk-Tikich block of Ukrainian Shield

This work discusses some features of geological structure of the Rosinsk-Tikich block of Ukrain-ian Shield. New data about composition of rocks, their protocomposition, conditions of formation and structure of supracrustal formations section have been obtained. New approach is offered to their stratifi-cation. These formations are considered to be as common series of metamorphic sedimentary-volcanic rocks -rosinsk-tikich series, in which such layers are allocated (from top to the bottom): mizinovsky, vo-lodarsk-belocerkovsky and lysiansky. Potassium depleted granites of neoarchean and paleoproterozoic bifeldspar granitoids are distinguished within ultra metamorphic formations. The former are paragenetic-cally associated with supracrustal layers and comprise continuous succession of rock groups combined in tetievsky complex: diorite, quartz diorite - tonalite, granodiorite - plagiogranite. Possibility of remobili-zation of tetievskiky granitoides without the substantial alteration of their compositionin paleoprotero-zoic (zvenigorodsky complex) is not improbable. Bifeldspar granites of Bygsk-Rosinsky megablock, in contrast to adjacent Volynsky and Ingul'sky megablocks, were formed on preliminary granitized rocks rather than on host supracrustal layers. They are considered as regressive ones that formed during tectono-magmatic activation. Four large subsequently formed rocks associations, antonovskaya, boguslavskaya, ol'shanickaya and associations of aplite-pegmatitic and pegmatitic granites are distinguished among bifeldspar granites. Taken together these rock groups and associations comprise umanskii complex, the age of formation of which is determined by interval of 2080-1990 million years.