Givetian Stage

(named for the city of Givet, department of Ardennes, France, near the Belgian border), the upper-most stage of the Middle Devonian series. It was identified by the Belgian geologist J. Gosselet in 1880 in the Ardennes region. It corresponds in time to the beginning of the sea’s advance onto the continental platforms (the Devonian transgression). The beds of the Givetian stage are represented by marine, lagoon, and continental sediments. Marine fauna is widespread on the Russian platform, in the Urals, on Novaia Zemlia, and in the Caucasus, Middle Asia, and the northeastern part of Asiatic USSR. Among the marine beds of the Givetian stage, carbonaceous sediments with brachiopods (Stringocephalus burtinii Defiance, Uncites gryphus Schloth) and, more rarely, with goniatites (Maenioceras, Agoniatites) predominate. Lagoon and continental beds are also quite common (northwestern part of the USSR, Scotland). They are represented by red sandstones and clays with fossils of fish (Pterichthys, Coccosteus), brachiopods of the genera Estheria and Lingula, and plants. Deposits of petroleum, bauxite, and hard coal have been found in beds of the Givetian stage.