Namurian Stage

(named after Namur Province, Belgium), the upper stage of the Lower Carboniferous in the classification scheme adopted in the USSR and the lower stage of the Upper Carboniferous in the scheme used in Western Europe. In Europe, North America, and Kazakhstan the Namurian stage is represented by marine deposits containing ammonoids, brachio-pods, and foraminifera or by continental deposits containing plant remains (Lycopsida, articulated stem plants, ferns, and pteridosperms). In some parts of Siberia, Mongolia, and China identification of the Namurian stage is more difficult because of the uniqueness of the organic remains.