The stratigraphy of the Pyeongan Supergroup of South Korea: A review

The Pyeongan Supergroup can be divided into seven lithostratigraphic units (Moscovian to Early Triassic?) in the Samcheok coalfield and four lithostratigraphic units (Bashkirian to Artinskian) in the Yeongwol coalfield of South Korea. On the basis of fusulinid biostratigrapic data in the Yeongwol coalfield, the boundary between the Carboniferous and Permian strata of the Pyeongan Supergroup has been considered as unconformity since the Kasimovian and Gzhelian strata are missing. Protriticites and Triticites, which are the cosmopolitan index fusulinids indicating the Kasimovian and Gzhelian age, are not found from the uppermost part of the Geumcheon and Pangyo Formations. Recently some fusulinids such as Xenostaffella koreaensis, Hanostaffella magna, and Fusulina danyangensis found from the uppermost part of the Geumcheon and Pangyo Formations are recognized as the early Kasimovian-type fusulinids, although the upper Kasimovian- to Gzhelian-type fusulinids are still missing.