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 si milar trend in the deepening and shallowing of the sedimentation envir onment occurs in the two palaeogeographically distinct areas. The stra tigraphic 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 s ystems tract in the late P. rhenana zone. A major sequence boundary wi thin the latter zone is indicated by an unconformity in intraplatform and platform areas and by a conformity in the basinal area. The upperm ost sediments within the late rhenana zone correspond to a lowstand sy stems tract. A rapid flooding took place near the base of the Palmatol epis linguiformis zone and dark shales and limestones formed. A second sequence boundary coincides with or is very close to the Frasnian-Fam ennian boundary (base P. triangularis zone). The global extinction eve nt at the Frasnian-Famennian boundary coincides with an important eust atic fall in sea level. The proposed stratigraphic subdivision should allow worldwide correlations of shallow and deep water deposits.