Transgressive surface as sequence boundary

Analysis of the four cases of the sequence boundary (SB)-transgressive surf ace (TS) relation in nature shows that applying transgressive surfaces as s equence boundaries has the following merits: it improves the methodology of stratigraphic subdivision; the position of transgressive surface in a sea level curve is relatively fixed; the transgressive surface is a transformin g surface of the stratal structure; in platforms or ramps, the transgressiv e surface is the only choice for determining the sequence boundary; the tra nsgressive surface is a readily recognized physical surface reflected by se ismic records in seismostratigraphy. The paper reaches a conclusion that to delineate a SE in terms of the TS is theoretically and practically better than to delineate it between highstand and lowstand sediments as has been d one traditionally.