1 A stage in the Mississippian, comprising the Chadian, Arundian, Holkerian, Asbian, and Brigantian Substages (these are also stage names in western European stratigraphy). The Visean is preceded by the Tournaisian, followed by the Serpukhovian, and dated at 345.3–326.4 Ma (Int. Commission on Stratigraphy, 2004).
2 The name of the corresponding European series which has its lower boundary at the base of the Chadian Stage near Clitheroe, Lancashire, England. It is roughly contemporaneous with the upper Carboniferous Limestone Series (Britain), and the upper Osagean, Meramecian, and lower Chesterian (N. America). See also dinantian.