International correlation

Globally, the Carboniferous System can be subdivided into two time intervals, associated with a climatic change which produced quite distinct floral and faunal distribution and characteristics of sedimentation (Wagner & Winkler Prins 1991). The early Carboniferous, equivalent to the Mississippian of the U.S.A. and Lower Carboniferous of Russia, was a time of equitable climate in which sea levels were generally high and successions within low latitudes are typically marine. Unobstructed marine communication between the Palaeo-Tethys and Panthalassan shelves (Davydov et al. 2004) allowed marine fauna to have a world-wide distribution, in which latitudinal variations were stronger than longitudinal differences (Ross & Ross 1988). The late Carboniferous, equivalent to the Pennsylvanian of the U.S.A., and Middle and Upper Carboniferous of Russia, is typified by coal-bearing successions that displayed marked latitudinal climatic differentiation associated with the Gondwanan Ice Age. The mid-Carboniferous boundary, which separates the two climatic periods, is associated with widespread regression and on many cratonic areas by the presence of a nonsequence or unconformity. The comparable transition is seen in Western Europe between the Visean and Namurian stages, though this is not a direct time equivalent of the Mississippian – Pennsylvanian boundary (Fig. 2.1). The carbonate-dominated succession of the Visean and terrestrial clastic-dominated succession of the Namurian are interpreted as a facies change with no world-wide significance (Wagner & Winkler Prins 1991).