The Carboniferous System. Use of the new official names for the subsystems, series, and stages

As a result of votes by the Subcommission on Carboniferous Stratigraphy [SCCS] that were ratified by the International Commission on Stratigraphy [ICS] and the International Union of Geological Sciences [IUGS] over the period 1999-2004, the official subdivision of the Carboniferous System has been substantially modified. For subsystems, the terms Mississippian and Pennsylvanian should be used in all regions of the world to replace the more ambiguous and more awkward terms Lower and Upper Carboniferous. Regional geographic names for series and stages may continue to be used in those regions in which they developed, specifically in Western Europe, the USA, and China. However, their global equivalents should be denoted equally, particularly as they become better correlated, in order to facilitate global correlation in future work. The SCCS also voted to standardize the scale of all regional units termed stages at rough equivalency with the global stages now recognized in the Carboniferous (which are similar in scale to those in the adjacent Devonian and Permian Systems). Therefore, the up to 26 subdivisions of the Tournaisian, Visean, Namurian, Westphalian and Stephanian of the regional western European classification should now be ranked and termed only as substages.