Stages of Granitoid Magmatism in the Eastern Part of the Kazakhstan Composite Continent in the Early–Middle Paleozoic

Abstract

For the northeastern part of the Chingiz–Tarbagatai segment of the Boshchekul–Chingiz folded area, U‒Pb age estimates of Middle Paleozoic granitoid complexes were obtained for the first time and their geochemical features were described. The recent data indicate a wide distribution of Late Silurian granitoids, represented by I-type rocks, on this territory. Early Devonian rocks form a number of separate volcano-plutonic structures, the granitoids of which can be classified as A-type. The compositional features of granitoids formed during the Cambrian‒Devonian enable one to trace the evolution of the crust of this part of the Chingiz–Tarbagatai segment from an ensimatic island arc to a volcanic belt with a relatively mature continental-type crust.