This volume documents the present state of knowledge of the geology of the German North Sea sector. The geological synthesis is based on a large amount of geophysical and geological data. High quality data were available from a comprehensive network of seismic lines shot between 1972 and 1989 (avg. line distance: 2 km). The seismic data were geologically interpreted by integrating the well data of 32 offshore boreholes as well as data from wells in the three miles zone off Germany and onshore wells. The bulk of these data is from industrial sources previously unavailable. Lithostratigraphical and log-correlation of the offshore area with the well known onshore Permian, Mesozoic and Tertiary sequences are well established in detail. Also, new gamma ray measurements along the Helgoland Buntsandstein cliffs have been incorporated in order to correlate these outcrops with the subsurface lithological sequence of the LowerTriassic. The results of these investigations are documented on 14 large format structural maps, one coloured subcrop map and 12 coloured geological sections. They enable the reader to quickly understand the structural framework of the region. The accompanying text is divided into a brief outline of the structural units of the studied region, a review of the paleogeographical and structural development and a detailed description of the individual post-Permian structures of the region.