Evolution, source and tectonic significance of Early Mesozoic granitoid magmatism in the Central Asian Orogenic Belt (central segment)

The generation of the Early Mesozoic granitoid magmas in the NMTB and the CMEB was dominated by the ongoing closure of the Mongol-Okhotsk Ocean and some was probably related to a mantle plume process. They were possibly derived from subducted materials melting or juvenile components with some probable contributions from ancient continental crust. Early Mesozoic granitoid magmas in the SMXB, the AB and the BIJB were generated in a post-/non-orogenic setting after the closure of the Paleo-Asian Ocean and were the results of partial melting of crustal components in response to underplating of mantle-derived magmas, most likely linked to lithospheric thickening and delamination and asthenospheric upwelling. Early Mesozoic granitoid magmatism provides critical information on Mesozoic post-accretionary tectonic evolution of the Paleo-Asian Ocean and transitional tectonic regimes from Early Mesozoic subduction to Late Mesozoic closure of the Mongol-Okhotsk Ocean as well as post-accretionary continental growth.