Regionally developed, mature, vertisols and calcisols are used to distinguish and correlate nonmarine, fourth order sequences (major cyclothems) consisting of fluvially-dominated strata with their down-dip marine-cored counterparts.

Initial stages of sequence-bounding paleosol development occurred on interfluves during FSST and LST under well-drained oxidizing conditions and strongly seasonal climate.

Sediment bypassing allowed for prolonged pedogenesis lasting 10s to 100s of thousand years; gleying of soils and local histosol development occurred during TST when local water tables rose due to rising sea level and wetter, less seasonal climate.

Microconchid limestones formed under lacustrine, palustrine, and possibly brackish intertidal conditions and represent maximum flooding surfaces within predominantly terrestrial sequences.

Coarsening-upward bay- and lake-fill sequences formed during the HST.

Sea-level/base level was the primary control on high-frequency variations in accommodation space within the coastal plain fluvial systems.

A nonmarine sequence stratigraphic model and a polygenetic paleosol model are developed.