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The contact between the continental redbeds of the Early Permian Rotliegendes and the marine sediments of the Late Permian Zechstein is a widespread and significant stratigraphic interface in the western European North Sea basin. It is this boundary that the economically important Weissliegendes reservoir sandstone beds are present. Petrologic examination of the Weissliegendes sandstone and adjacent units, in the outcrop belts of eastern England and western Germany and in the subsurface in the southern North Sea and in the Netherlands, gives indications of their origins and suggests possible distribution patterns for the Weissliegendes reservoir sandstone bodies in the North Sea basin. The Weissliegendes sandstones, whose compositional aspects are controlled by local cond tions, range from orthoquartzites, to subarkoses, to subgraywackes, to graywackes. The sandstones are multicycle deposits, largely derived from the local marine reworking of Rotliegendes sandstone, mudstone, and conglomerate. Interpretations of the textural and bedding characteristics of the Weissliegendes sandstone bodies indicate that they are of a subaqueous origin (e.g., submarine sand ridges and banks), rather than of the eolian dune origin that has been long postulated for them. The distribution of the sandstone bodies is irregular with some having elongate shapes several kilometers wide, up to 40 m thick, and several tens of kilometers long. These sandstone bodies are most prevalent on the flanks of pre-Permian structural highs, in places overlapping the Rotliegendes and extending onto the Variscan basement.
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