摘要
The Devonian-Carboniferous (D/C) boundary in China has been studied for a long time. The type section of the lower Carboniferous in China is situated between Wuliqiao and Heishiguan villages, south of Dushan County, Guizhou Province. Yu Jianzhang (1931) established two coral zones: the lower one is the Cystophrentis zone in the