Biostratigraphy of the Akiyoshi Limestone Group,

10 Yasuhiro Ota
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Fig. 2. Approximate ranges of important fusulinacean genera near the Virgilian-Wolfcam
pian boundary in the Big Hatchet Mts. (after Wilde, 1984; Rui and Zhang, 1987).
fauna in the section of the "Carboniferous" to Permian continuous sediments above
the uppermost Pseudoschwagerina Zone or the Robustoschwagerina schellwieni Zone of
Permian age. This sequence seems to represent the Liangshan Member, and Rui
advocated that the lower boundary of the Permian should be placed below this
limestone sequence. Afterwards, some workers supplemented and revised the
definition on the traditional boundary. At present 18 main proposals for the
Chinese Carboniferous-Permian boundary are known (Rui and Zhang, 1987).
These Chinese proposals have been continuously discussed and they are put into six
main opinions about the definition of the Carboniferous-Permian boundary (Table
3).
1. Putting the boundary between the Carboniferous and Permian at the top of
Schwagerina Zone, is known as the traditional boundary in China and used for more
than 40 years. In short, the boundary is compared with the top of the Pseudo
schwagerina Zone or the Sphaeroschwagerina Zone, namely the top of the Maping
Formation or the Chuanshan Formation, correlated with the boundary between the