R1: Characterization and description of minerals

[R1P-14] Occurrence of Co ores from the Eboshi deposit, the Naganobori copper mine, Yamaguchi, Japan

*Mariko Nagashima¹, Yuji Imoto², Yukina Morishita² (1. Yamaguchi Univ. Earth Sci., 2. Yamaguchi Univ. Sci.)

Keywords:Naganobori, Copper, Skarn, Cobalt

Mineral assemblages and chemical compositions of ore minerals in Co-rich ores from the Eboshi deposit, Naganobori copper mine, Yamaguchi, Japan were investigated. The major ore minerals are cobaltite, chalcopyrite (Cpy), and early stage pyrite (Py-I) and later stage pyrite (Py-II). Py-II is enriched in arsenic. Bi-bearing minerals are associated with cobaltite. Ag-bearing minerals also occur. As results, Cpy and Py-I were formed in the early to middle stages; cobaltite, Py-II and Bi-minerals were of the middle stage; and Ag- and Te-minerals were crystallized in the late stage.