ON THE AGE OF THE CHARNOCKITOIDS OF THE TASHLYK COMPLEX OF THE INHUL REGION OF The UKRAINIAN SHIELD

Abstract

Zircons from charnockitoids of the Tashlyk complex from the Pryinhul syncline were studied and dated in order to determine their chronostratigraphic position. Zircons of two age generations were identified, namely the Early Archean (ca. 3 Ga) and the Early Proterozoic (2.0±0.1 Ga). The presence of the former generation indicates that the protolith for charnockites have been represented by the rocks older than the Spasove Series, which is considered to be Proterozoic in age. At ca. 2.0±0.1 Ga Archean rocks together with rocks of the Inhul-Inhulets Series, underwent granulite metamorphism. This event resulted in crystallization of the second (Paleoproterozoic) generation of zircon in charnockites. Archean zircons found in the rocks of the Tashlyk complex, which correspond morphologically to granitoid of the amphibolite facies, differ from Eoarchean zircons in enderbites of the Haivoron complex, which partially retain their appearance during the Neoarchean and Paleoproterozoic tectonic-magmatic events.