GRANODIORITES OF THE GRENVILLE PHASE IN THE KOKCHETAV BLOCK, NORTHERN KAZAKHSTAN

Abstract

The Kokchetav Block is composed of Precambrian metamorphic rocks of the Zerenda and Sharyk groups. The Zerenda Group (amphibolite-facies rocks) is overlain with geological and metamorphic unconformities by greenschists of the Sharyk Group. Based on the U–Pb zircon dating, gneisses of the Zerenda Group in the central Kokchetav Block are estimated at 1300–1900 Ma.