Metallogenesis of two types of late Early Yanshanian granitoids in South China： Case studies of south Jiangxi and southwest Fujian

Abstract：Late-stage Early Yanshanian granitoids are widely distributed in South China and closely related to metallogenesis. They have two different distribution patterns, being EW-trending in Nanling and NE-trending in Wuyi area. Granitic rocks formed in two different tectonic settings have different geochemical characteristics. The little stocks in southern Jiangxi Province are closely related to W and Sn mineralization, quite different from things of big batholiths. The little stocks and big batholiths might have been formed by partial melting of the crust-derived argillaceous-arenaceous metasedimentary rocks related to Proterozoic crust; nevertheless, fluid was present during magmatic evolution and experienced highly differentiation and evolution in the formation of little stocks, whereas NE-extending granitoids were probably formed by partial melting of argillaceous metasedimentary rocks related to Mesoproterozoic crust. During that period, the mainland lithosphere of Nanling and adjacent regions belonged to an extensional setting, southeast China was mostly under the tectonic framework of East Asia active continental margin, and the collision and compressional role of the Pacific plate toward East Asian continental margin began to emerge.