Late Paleozoic granitoid magmatism of Eastern Kazakhstan and Western Transbaikalia: plume model test

Abstract

We present results of a comparative study of Late Paleozoic granitoids of Eastern Kazakhstan and Western Transbaikalia composing the large Kalba-Narym and Angara-Vitim batholiths. We have established that despite the different geologic history of these regions, granitoid magmatism there proceeded nearly synchronously at the Carboniferous/Permian boundary (330–280Ma) and was accompanied by mantle magmatism. The regularities of its evolution are considered in terms of the plume model and different stages of interaction of mantle plumes with the lithosphere. The major principles of plume-lithosphere interaction in accretion-collision fold belts have been formulated: (1) Plume-lithosphere interaction results in large-scale melting of sublithospheric mantle, lower lithosphere, and crustal substrates warmed by the preceding orogenic processes; (2) The processes last 30 to 50 Myr and produce large volumes of igneous rocks, mostly granitoids; (3) The sequence of formation of granitoid and basic igneous complexes and the metallogenic specialization can be different and depend on the lithosphere structure and preceding geologic history of the region.