Geochemistry of the Mesozoic basaltic rocks in southern Hunan Province

Southern Hunan Province is famous for its intensive rare, radioactive and other metal elements’ mineralizations. There is a relation between the basaltic rocks and mineralizations in space, time and ore-forming elements. The Jurassic-Cretaceous (204–81 Ma) basaltic rocks consists mainly of alkali-basalt and tholeiitic basalt formed in plate environment. Trace elements and Sr, Nd, Pb isotopic compositions show that the regional mantle source was metasomatized shortly before the partial melting. The alkali basalt and tholeiitic basalt might be 3%–5% and 10%–15% of the partial melting of the enriched mantle source respectively. Obviously the enrichment of the regional mantle played an important role in formation of the large and super-large deposits in southern Hunan Province.