Sequence stratigraphy of the Frasnian-Famennian transitional strata: a comparison between South China and southern Belgium

The sedimentological evolution of the Frasnian-Famennian transitional strata in South China and southern Belgium has been investigated. A similar trend in the deepening and shallowing of the sedimentation environment occurs in the two palaeogeographically distinct areas. The stratigraphic succession has been subdivided into depositional sequences. A general deepening occurs in the Palmatolepis rhenana conodont zone. During the most rapid rise in sea level, a transgressive systems tract formed. This transgressive systems tract is followed by a highstand systems tract in the late P. rhenana zone. A major sequence boundary within the latter zone is indicated by an unconformity in intraplatform and platform areas and by a conformity in the basinal area. The uppermost sediments within the late rhenana zone correspond to a lowstand systems tract. A rapid flooding took place near the base of the Palmatolepis linguiformis zone and dark shales and limestones formed. A second sequence boundary coincides with or is very close to the Frasnian-Famennian boundary (base P. triangularis zone). The global extinction event at the Frasnian-Famennian boundary coincides with an important eustatic fall in sea level. The proposed stratigraphic subdivision should allow worldwide correlations of shallow and deep water deposits.