THE TRIASSIC STRATIGRAPHIC FRAMEWORK OF THE GUIYANG AREA,GUIZHOU PROVINCE

Through field mapping and tracing of unconformities, four unconformitybounded stratigraphic units （or "sequences"） have been recognized in the Triassic carbonate platform-basin transition zone of the Guiyang area, Guizhou Province. They may be essentially correlated with the table of the cycle of the Triassic global sea-level changes presented by Harke et al. （1988）. On the basis of an analysis of lithofacies and stratigraphic structure, four sedimentary systems may be distinguished; they are the marine transgressive carbonate rock gentle slope, high-water level carbonate rock platform, low-water level carbonate rock slope and basinal clastie-carbonate rock mixture. Thus the features of the Triassic stratigraphic framework in the Guiyang area has been ascertained. The transgression surfaces represent important depositional breaks in the basin sequences. Therefore the author proposes that it is advisable to take the unconformity-transgression surface in the subaerial exposure zone as the interface of the unconformity-bounded stratigraphic units （"sequences"）. More intensive biostratigraphic and chronostratigraphic studies should be made in the future.