General features and classification

Paleozoic-Mesozoic volcanogenic stratiform Cu deposits in Japan which are generally metamorphosed have been called Besshi-type deposits (Kato, 1937) or bedded cupriferous iron sulfide deposits (Kanehira and Tatsumi, 1970). 

General descriptions of Besshi-type deposits have been given by Kanehira and Tatsumi (1970), Franklin et al. (1981) and Fox (1984). 

Besshi-type deposits in Japan are divided into Besshi-subtype and Hitachi-subtype based on geological, mineralogical and geochemical characteristics (Sato and Kase, 

Sato and Kase (1996) summarized these characteristic features and divided Besshi-subtype into Group A (sediment-barren type) and Group B (sediment-covered type) (Table 2.21). These characteristic features of these Besshi-type deposits in Japan, mainly focusing on the Besshi-subtype and comparing of these features with those of Kuroko and midoceanic ridge deposits are described below. 

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