Abstract Our paper presents the first draft of a geomorphological map of the German North Sea and Baltic Sea. The inspiration for this map comes from the international collaboration of marine researchers within the European EMODnet Geology Project ( https://www.emodnet-geology.eu/ ). The current climate change intensifies the natural processes of change in nature. Within the framework of various nature conservation projects, the importance of marine sediment structures on marine fauna and their reproductive cycles, sedimentation conditions, currents, etc. has been investigated. In order to be able to make statements for the German seas and document changes, the current state must first be recorded.

Abstract The Tornquist Fan, reflecting the northern part of the Trans-European Suture Zone, comprises a series of fault zones and major single faults, striking mainly subparallel to the SW margin of the Fennoscandian Shield. The deep-seated faults of Wiek, Nord Jasmund and Schaabe, which cross the northern part of Rügen Island and areas of the adjacent Baltic Sea from NW to SE, originated in the late Paleozoic. They are accompanied by younger faults, especially in the Pomeranian Bay, that were formed by Mesozoic tectonic processes. Based on reprocessed offshore seismic lines east of Rügen, a polyphase evolution for the Wiek Fault System is proposed. It implies changes in the stress field since the Caledonian Orogeny. Crustal extension in the Middle Devonian led to the formation of basins along the SW margin of Laurussia. Subsequent compressional movements, induced by the distant Variscan Orogeny, resulted in segmentation and block faulting of the Rügen Basin prior to the late Carboniferous. These Paleozoic faults were reactivated by Mesozoic extensional stress regimes. In addition, new en echelon faults were generated, contemporaneously with the formation of the Western Pomeranian Fault System. Since the Late Cretaceous (Africa–Iberia–Europe convergence), selected major normal faults have been reactivated as reverse faults.

Abstract Based on reprocessed offshore seismic lines acquired during oil and gas exploration in the 1980s, we reconstruct the formation and reactivation of major fault systems in the southern Baltic Sea area since the late Paleozoic. The geological evolution of different crustal blocks from the Caledonian Avalonia–Baltica collision until the Late Cretaceous–Paleogene inversion tectonics is also examined. The detected fault systems occur in the northern part of the Trans-European Suture Zone (TESZ) and belong either to the late Paleozoic Tornquist Fan or to the complex Western Pomeranian Fault System (WPFS) generated during Mesozoic extensional movements. While the NW–SE-trending deep Wiek Fault separates the Arkona High from the Middle Rügen Block, the NNW–SSE-trending Agricola Fault demarcates the Middle Rügen Block to the Falster Block in the west. Together with the Plantagenet Fault and numerous younger faults in the Mesozoic cover, it forms the Agricola Fault System. Furthermore, structural analyses of the Prerow Fault Zone above the Prerow salt pillow and the Werre Fault Zone crossing the Grimmen High indicate a complex fault history.

Abstract The North German Basin yields enormous geothermal resources of more than 13 000 EJ (exajoule: 1 EJ = 1 × 10 18 J) heat in place bound to Paleozoic petrothermal and Mesozoic hydrothermal reservoirs. So far, these resources are only exploited at a few localities. Thus, geothermal energy is considered an underutilized energy resource. Despite long-term experience in exploiting Rhaetian hydrothermal reservoirs, the exploration risk remains high, which is mainly related to high expectations on reservoir thickness and quality. Previous exploration campaigns have identified potential hydrothermal reservoirs in six Mesozoic reservoir complexes. But, as high-resolution subsurface maps are not available, the reliable prediction and targeting of reservoirs remains an unsolved problem. As such, an exploration strategy integrating methods of sedimentology, palaeontology, petrography and reservoir characterization was applied to a large database of cores and wireline logs. This contribution details the key results of the exploration of Upper Keuper and Middle Jurassic reservoir complexes, including high-resolution subsurface facies, sandstone thickness and reservoir quality maps. Sets of these maps enable the reliable prediction and targeting of individual hydrothermal reservoirs, and, thus, make a significant contribution to a lowered exploration risk.

Abstract Early Jurassic plesiosaurian fossils are rare in the Scandinavian region, with a few isolated bones and teeth known from Bornholm, and anecdotal finds from East Greenland. The only other identifiable specimens derive from Toarcian-aged (based on ammonites) erratics deposited during Late Pleistocene glacial advances near the town of Ahrensburg, NE of Hamburg in northern Germany. The geographical source of these transported clasts is debated, but reconstructed ice-flow directions and lithofacies comparisons implicate either the offshore Baltic Sea between the Island of Bornholm and Mecklenburg–Vorpommern (Germany) or, less probably, south of the Danish Archipelago (Mecklenburg Bay). These regions collectively bordered the Fennoscandian landmass and adjacent Ringkøbing-Fyn Island in the late Early Jurassic, and were dominated by near-shore marine deltaic to basinal settings. The Ahrensburg plesiosaurian remains include postcranial elements reminiscent of both the microcleidid Seeleyosaurus and the rhomaelosaurid Meyerasaurus . These occur alongside other classic ‘Germanic province’ marine amniotes, such as the teleosaurid crocodyliform Steneosaurus and ichthyosaurian Stenopterygius cf. quadriscissus : thus, advocating faunal continuity between Scandinavia and southern Germany during the Toarcian, and a less pronounced marine reptile faunal provinciality than previously assumed.