Introduction to and classification of manganese deposits of China

Manganese (Mn) ore deposits are widely distributed in China and can be divi ded into six types based on origin and subsequent modifications: (1) sedime ntary, (2) volcanic-sedimentary, (3) metamorphosed, (4) hydrothermally modi fied, (5) hydrothermal, and (6) supergene. Sedimentary and supergene Mn ore deposits are economically the most important. Mn ore deposits and ore-bear ing sequences are distributed temporally from the Proterozoic through the Q uaternary, but they principally are Middle Proterozoic, Sinian, Cambrian, O rdovician, Devonian, Carboniferous, Permian, Triassic and Quaternary ages. The largest Mn metallogenic periods in China are Sinian and Devonian, in co ntrast to the widespread Proterozoic, Cretaceous and Oligocene Mn deposits found elsewhere in the world. Mn-bearing stratigraphic successions in China can be divided into six types of lithologic associations: (1) black shale series, (2) chert-mudstone-limestone, (3) carbonate, (4) mudrock-carbonate, (5) volcanic-sedimentary, and (6) Epeirogenic elastic rock types. The most important Mn metallogenic regions in China are: (1) Yanliao, (2) border of Hunan-Sichuan-Guizhou-Hubei Provinces, (3) Southern Shaanxi and northeaste rn Sichuan, (4) Middle Guizhou and eastern Yunnan, (5) Southwestern Guangxi , (6) Southeast Yunnan, (7) Hunan-Guangxi-Guangdong-Fujian, and (8) Xinjian g. The most striking characteristics of Mn ore deposits in China are the wi de distribution in geological ages and variety of compositional types of or es, such as Fe-Mn, B-Mn, P-Mn, Go-Mn, Ca-Mn, Ca-Mg-Mn, among others. The pr imary Mn ores of China are mainly Mn carbonates. (C) 1999 Elsevier Science B.V. All rights reserved.