A New Tectonic Model for the Genesis of Adakitic Arc Magmatism in Cretaceous East Asia

A recently introduced plate reconstruction model refutes the migration of the Izanagi-Pacific ridge formerly considered to be responsible for the adakitic arc magmatism in East Asia during the Cretaceous. This chapter suggests that northeast-to-southwest migration of the East Asian continental blocks during the Cretaceous resulted in apparent southwest-to-northeast migration of an intracontinental mantle plume from eastern China to Far East Russia. The apparent migration of the mantle plume explains the southwest-to-northeast migration of intracontinental adakitic rocks and A-type granitoids formed by partial melting of delaminated thickened lower mafic crust and decompression melting of the mantle plume, respectively, and the simultaneous migration of adakitic arc magmatism generated by a hot lobe of the mantle plume injected into the mantle wedge, producing partial melting of subducted oceanic crust.