Albian-Cenomanian Orogenic Belt and Igneous Province of Pacific Asia

Geological data and about 300 precision geochronological and geochemical determinations are analyzed to identify the Albian-Cenomanian continental-margin orogenic belt and simultaneous igneous province of Pacific Asia. The orogenic belt represents a newly formed region of continental lithosphere that resulted from the deformation of mainly Jurassic-Early Cretaceous epioceanic terranes. The igneous province is made up of volcanic and intrusive complexes of mostly Albian age, which are syn-orogenic within the belt and post-orogenic beyond it. The igneous rocks include A-, I-, and S-type granitoids; adakites; and VAB- and OIB-type basalts and their intrusive analogues. Both the orogenic belt and the igneous province were formed in a tectonic setting of a transform continental margin between 110 and 95 Ma. The interval of 103-97 Ma became the peak of orogenic and magmatic activity caused by upwelling of the hot asthenospheric mantle through destructed stagnant slabs of the pre-Albian subduction. The Albian-Cenomanian age of the large gold, copper, tungsten, tin, and other ore deposits argues in favor of recognition of the corresponding metallogenic province. The first age data (100-97 Ma) are reported for the granite from the Malmyzh deposit within the Sikhote-Alin Ridge.