ПАЛЕОАРХЕЙСЬКИЙ ВІК АКЦЕСОРНОГО ЦИРКОНУ З ТОНАЛІТОВИХ ГНЕЙСІВ ВЕРХНЬОТОКМАЦЬКОЇ ТОВЩІ ПРИАЗОВСЬКОГО МЕГАБЛОКА

Анотація

The tonalite gneiss outliers which contain zircon with the age of 3 560±50 Ma have been
first discovered in the Tokmak river head. Gneisses of the similar composition have been de-
scribed in the stratotype section of Verkhnyotokmak thickness (West-Priazovan series); they
form the grey gneiss crystalline basement of the Peri-Azovian megablock. Post-kinematic
pegmatoid granites which intrude tonalite gneisses contain zircon whose age is 2 036 Ma.
Key words: zircon, monazite, tonalite gneisses, grey gneiss crystalline basement, Pa-
leoarchean, isotopic age, Peri-Azovian megablock.