Alb-Cenomanian granitoid magmatism and copper ore genesis of the Sikhote-Alin

Abstract

Late Albian-early Cenomanin epoch of Au-Cu porphyry mineralization has been distinguished within the Sikhote-Alin. It is associated with the Alb-Cenomanian granitic rocks which emplacement coincided with the processes of orogeny and neoformation of continental lithosphere caused by compressive stress in the setting of transform continental margins of that time. The intrusion of the granitic magma into the crust of Jurassic accretionary wedge terranes and Early Cretaceous terrane of epicontinental turbidite basin provoked development of Au-Mo-Cu and Cu-Au-W ore genesis, respectively. U-Pb dating of zircons from host granites of the Malmuzh Au-Cu deposit yielded Alb-Cenomania age of 100-95 Ma. This age harmonizes with the age data reported by other researchers on the granitic rocks of East and Southeast Asia which are productive for hydrothermal mineral deposits of copper, gold, tin and other metals. Such age consistency suggests that there is Albian-Cenomanian metallogenic megabelt extending throughout the entire East Asian continental margin.