Tournaisian

The main elements that prompted the international community to use the Tournaisian as a name for the oldest stage of the Mississippian Subsystem are the same as those for the Viséan, i. e., the quality of exposures in southern Belgium, the diversity of facies, the pioneering palaeontological work that started in the mid 19th century and development of foraminiferal, conodont and rugose corals zonations in the last decades. The numerous Tournaisian sections in southern Belgium document a progressive change in environmental setting, from a ramp during the early Tournaisian to a shelf during the late Tournaisian. The spectacular late Tournaisian Waulsortian buildups that occurred within 2 third-order sequences had a strong impact on subsequent Viséan sedimentation. Recent advances in understanding the sequence stratigraphy has led to new insights on correlation between the central Dinant Sedimentation Area and more proximal areas. Service de Paléontologie animale, Université de Liège, Bâtiment B18, Allée du 6 août, Sart Tilman, B-4000 Liège; E-mail: [email protected]