Intraplate magmatism in Central Asia and China and associated metallogeny

Abstract

Large areas of central Asia and mainland China have been affected by intraplate anorogenic magmatism, linked to mantle activity from the Palaeoproterozoic to present day. This magmatism is manifested by layered mafic–ultramafic intrusions, flood basalts, bimodal volcanic rocks, dyke swarms, I- and A-type granitoids, alkaline complexes, carbonatites and kimberlites. In this paper we discuss a selection of these thermal events, namely East Asia Mesozoic–Cenozoic, Siberian Traps, Emeishan, Tarim (Bachu), Yakutsk and South China. Mineral systems that are associated with the Asian intraplate magmatic events include Ni–Cu–PGE in mafic–ultramafic intrusions, porphyry Cu–Mo and skarn deposits, polymetallic veins and auriferous lode deposits generally hosted in granitoids, rare earths and rare metals in alkaline complexes and diamondiferous kimberlites. The anorogenic intraplate igneous rocks originate from mantle sources or mixed mantle and crustal sources and are related, directly or indirectly, to deep mantle plumes or to asthenospheric upwellings that occur in response to lower crust and subcontinental lithosphere delamination linked to collision and subduction processes.