Viséan
Geologic period
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The Visean, Viséan or Visian is an age in the ICS geologic timescale or a stage in the stratigraphic column. It is the second stage of the Mississippian, the lower subsystem of the Carboniferous. The Visean lasted from 346.7 to 330.9 Ma. Wikipedia
Epoch: Mississippian
Occurred: 346.7 (+/- 0.4) million years ago - 330.9 (+/- 0.2) million years ago
Alternate spelling(s): Visean, Visian
Lower boundary definition: FAD of the benthic foraminifer Eoparastaffella simplex
Lower GSSP ratified: 2008
Regional usage: Global (ICS)