Abstract:

The Caledonian granites take the second importance among the multi-aged granitoids in so-called South China Large
Granite Province. However, the pervious studies show less concern on the metallogenic aspects of Caledonian granites. Some early studies considered no important mineralization related to Caledonian granites. Based on some newly discovered granitic intrusionsof Caledonian ages, together with the synthetic assessment of related literature, the present paper reviews the general character of Caledonian granites and discusses the relationship between Caledonian granites and large scale rare metal metallogeneses in South China. Although the large-scale rare metal mineralization mainly took place in the Yanshanian Period of Late Jurassic Era,Caledonian granitoids of mostly Silurian Era made great positive effects. Some well-evolved Caledonian granites, such as those in Penggongmiao of southeastern Hunan, Niutangjie of northern Guangxi, Guiling of northeastern Guangxi, and Qingjie of Youjiang area, can cause W, Mo and Sn mineralization. Some others might serve as rare metal supply for mineralization associated with late-staged granites, such as Shilei of southern Jiangxi and Meiziwo of northern Guangdong. At Yijiang of southern Hunan, the weathering products of Caledonian quartz diorite form a unique REE-Sc deposit. The most important significance, however, is that the Caledonian Orogeny started the intra-continental crust evolution of South China. The Caledonian granitoids resulted mainly by melting of crust materials, instead of adding of mantle material. The following tectonic episodes such as Variscan, Indo-sinian, and Yanshanian, together with the accompanying granitic magmatism, promoted the forward evolution of crust. As a result, the crust of South China became highly matured, which is indicated by high enrichment of felsic components and lithophile rare metals, and finally yielded the largest rare metal mineralization in the world.

Key words: Caledonian, granite, large-scale mineralization, South China