Palaeotopography-governed sediment distribution—a new predictive model for the Permian Upper Rotliegend in the Dutch sector of the Southern Permian Basin

The Southern Permian Basin (SPB) formed a large, elongated saucer-shaped inland depression extending from the UK to Poland and from Belgium to Denmark. During the Middle to early Late Permian the SPB was filled progressively by playa sediments from its centre in northwestern Germany before it was flooded at the onset of the Zechstein. The Netherlands were situated at the southern part of the saline playa lake. The sediment fill has an onlap configuration upon the underlying Carboniferous and Lower Rotliegend strata. Although regional contour maps suggest a fairly gradual thinning of the Upper Rotliegend interval towards the basin edge, more careful examination reveals that there are prominent steps in thickness and facies. It can be concluded that these steps are defined by steps in the palaeotopography of the basin. These topographic steps are related to pre-Variscan and Variscan structural elements. During deposition of the Upper Rotliegend these large-scale topographic steps defined the location of the main fluvial fairways towards the basin centre, extensive (mud)flat areas, and the relative highs on which the dune fields developed. Next to these large topographic elements relief inversion, differential erosion, and faults caused smaller-scale topographic relief elements. This relief exerted prominent influence on the sediment dispersal patterns and sediment type both laterally and vertically. This holds especially true for the basal Rotliegend sandstones and in the pinch-out area near the playa margin. Copyright © 2011 SEPM (Society for Sedimentary Geology).