Periodic Law Patterns of Sequence Stratigraphy

Abstract

Abstract Based on the current theory of sequence stratigraphy, this study employs stillstand normal regression (SNR) to replace the method of highstand normal regression (HNR) to establish shoreline trajectory and sediment supply models of off-lap and onlap-type sequences, respectively. The basic principle of the digital model-driven approach in this study is to decompose the shoreline trajectory (fst) and sediment supply trajectory (fss) into their vertical and horizontal projection vectors to establish periodic sufficient condition of shoreline trajectory and sediment supply trajectory, aiming to obtain the remnant maximum flooding surface (RMFS) and/or its intersecting subaerial unconformity (ISU) sequence model: HST (SNR)-FSST (FR)-LST (LNR)-TST (T). This model established the synchronic necessary condition of shoreline trajectory and sediment supply trajectory and obtained the periodic law patterns of sequence stratigraphy, proposed as “two rhombuses sandwiching one subaerial unconformity”. This study defines a sequence as: a sequence is a stratigraphic unit constrained by periodic sufficient condition and synchronic necessary condition of shoreline and sediment supply trajectories and is composed of a relatively conformable succession of genetically interrelated strata bounded at their top and base by RMFS and/or intersecting subaerial unconformities (ISU). Moreover, the periodic laws of sequence stratigraphy show that the RMFS is almost potentially correlative to the lower boundary of the stage B (global boundary stratotype section and point) of chronostratigraphic units and close to the biohorizon or first appearance datums (first appearance datums) of biostratigraphic units.