Paleozoic subduction and collision magmatism in west Mongolia: Evidence from geochronology and geochemistry of the intrusive rocks

Abstract

The Central Asian Orogenic Belt (CAOB) resulted from amalgamation of voluminous subduction – accretionary complexes of Late Neoproterozic to Mesozoic time. Mongolia is the heartland of the CAOB and geologically divided into four complexes; continental blocks, subduction complexes, sedimentary basins and Cenozoic cover sequences. The magma activity in the southern part of Lake zone would, therefore, be related to the continental collision event. Considering geochronology and geochemical features of the intrusive rocks, the subduction and collision events occurred in the Lake zone during Cambrian time. Finally, the North China craton collided to the Siberia craton, giving rise to collision-type metamorphism and S-type granite magmatism during Permian time in the Mongolian Altay region.