Comparative studies of the latest investigations in various parts of the marsh areas of Lower-Saxony (Germany) and of the Netherlands lead to the conclusion that despite different local influences upon the sedimentation characteristics the geology of the holocene layers must have been determined by factors which had more than only regional importance. The geology of the holocene layers of the southern Northsea coast is mainly determined by sea transgressions, originating from glacial eustatic changes of sea level. The influences of tectonic movements and other factors are, in comparison to this, only of minor significance. The sequence of the holocene sea transgressions on the southern Northsea coast are illustrated in a diagram on the basis of fiftyseven C14-determinations and of extensive field survey work. This diagram shows, in consideration of the subsiding rates of the sediments, the mean highwater levels of the sea at different time periods. Greater upward movements of the sea level occured during the Preboreal (8000—7650 B.C.), the Atlanticum (5500—2500 B.C.), and during the Subatlanticum (beginning 300 B.C.) until today. Opposite trends were found during the Boreal (6750—5500 B.C.) and the Subboreal (2500—300 B.C.). These retardations or interruptions of transgressions occured at approximately the same time during which the important regenerations of glacier took place an the American continent. These two most important incisions in the course of the holocene transgressions during the Boreal and Subboreal are used for subdividing the Holocene into 3 subdivisions (Old holocene, Middle holocene and Young holocene). Within these subdivisions a lower step (transgression acceleration) and an upper step (transgression retardation) are differentiated respectively. Today's status can be considered within the lower step of the Young holocene. A further subdivision of sequences can be derived from minor fluctuations of the transgressions. Thus the Lower Middle holocene is divided in 3 sequences, the Upper Middle holocene in 2 sequences and the Young holocene in 4 sequences. Each of these sequences is composed of one flooding phase and one silting-up phase.