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广西六景泥盆系剖面是我国泥盆系标准剖面之一 ,通过对其吉维阶 -弗拉斯阶界线上下地层进行详细的牙形石生物地层研究 ,自上而下识别出 12个牙形石带 :Palmatolepis jamieae带、Palmatolepis hassi带、Palmatolepispunctata带、Palmatolepistransitans带、上 Mesotaxisfalsiovalis带、下 Mesotaxisfalsiovalis带、Klapperina dispar-ilis带、上 Schmidtognathus hermanni- Polygnathus cristatus带、下 Schmidtognathus hermanni- Polygnathus cristatus带、上 Polygnathus varcus带、中 Polygnathus varcus带、下 Polygnathus varcus带。吉维阶 -弗拉斯阶界线 (即中 -上泥盆统界线 )由 Ancyrodella binodosa→ Ancyrodella rotundiloba early form→ Ancyrodella rotundiloba late form这一演化线系中的 Ancyrodella rotundiloba early form的首次出现确定 ,处于下 Mesotaxis falsiovalis带下部 ,在谷闭组底界之上 1.80 m处。
The Devonian section of Liujingang in Guangxi Province is one of the Devonian standard sections in China. Through detailed study of the conodont stratigraphy of the upper and lower strata of the Jwevi-Frase level, 12 teeth are identified from the top Belt: Palmatolepis jamieae, Palmatolepis hassi, Palmatolepispunctata, Palmatolepistransitans, Mesotaxisfalsiovalis, Mesotaxisfalsiovalis, Klapperina dispar-ilis, Schmidtognathus hermanni- Polygnathus cristatus, Schmidtognathus hermanni- Polygnathus cristatus, Polygnathus varcus band, medium Polygnathus varcus band, under Polygnathus varcus band. The first occurrence of the Jiyvi-Frasezon boundary (ie, the mid-upper Devonian boundary) from the Ancyrodella rotundiloba early form Ancyrodella binodosa → Ancyrodella rotundiloba early form → Ancyrodella rotundiloba late form Mesotaxis falsiovalis with a lower part, 1.80 m above the bottom of the valley closure group.