SequenceboundaryisstudiedindetailinreferencetothePermianGuadalupianLopingianboundary,basedonhighresolutioncorrelationofconodootzones.Aconceptualsynchronousstratigraphicboundary,correspondingtotheageofthesequenceboundarydatedintheconformableportionofthesequenceboundary,isdefinedasthesequencechronostratigraphicboundary(SCB).Thesequenceboundaryisprovedtobedualinnatureinregardstothesynchronyanddiachroneityofstratigraphicboundaries.Themeritsofthesequenceboundaryinstratigraphicsubpision,correlationandclassificationareelucidatedincomparisonwiththelithostratigraphicboundary,thebiostratigraphicboundaryandthetraditionalapproachoftheglobalstratotypesectionandpoint(GSSP).ByintegratingthevirtuesofthesequenceboundaryandtheGSSP,itisproposedthattheGSSPshouldbeestablishedintheconformableportionoftherelatedsequenceboundary.Theboundaryestablishedinlightofthisapproachisdefinedas
