It is between the Dogger Bank and the ridge dividing the northern from the southern North Sea basins, which runs between Norfolk and Friesland.
[1] In the Cromerian Stage, before more recent glaciation had influenced the area, a ridge of high ground, the Weald-Artois Anticline, joined the Upper Cretaceous chalk in Kent, England to that of the Boulonnais at Cap Blanc-Nez in the Pas de Calais, France.
It is possible that in the Cromerian Stage, the Outer Silver Pit was the bed of the combined Maas, Rhine, Scheldt and Thames.
Maps by some geologists[1] show rivers from the German part of the Urstrom's catchment area flowing northwards east of the Dogger Bank highland area; but Scandinavian ice reaching the Dogger Bank would have forced the Urstrom into another route.
When the Scandinavian and Scottish ice caps first met, the Urstrom (unless it found a way northwards under the ice) would have backed up into a huge lake in the southern North Sea, which finally found an outlet southwards over the Weald-Artois Anticline and helped to cut the valley of the Strait of Dover: see Strait of Dover#Geological formation.