Abstract Mesozoic extensional basins of the Southern Permian Basin (SPB) System became inverted from Late Cretaceous time onwards. Following a first Cretaceous ‘Subhercynian’ pulse of contractional deformation and basin uplift, several distinct inversion events of Cenozoic age were often described. The oldest of these is the ‘Laramide’ event of Paleocene age which coincides with the termination of chalk deposition and widespread regression around the North Sea Basin, whose axial part continued to subside. The spatial extent of these effects is too wide to be compatible with inversion by folding and reverse faulting. The width of the uplifting and subsiding regions was also too large to be consistent with folding of the entire lithosphere under tangential compression. There appears to be no unequivocal evidence of discrete structures formed or reactivated in the Laramide event. By contrast, well-documented younger inversion of approximately Late Eocene to Late Oligocene–(Miocene?) age affected the region from the Celtic Sea to the western Netherlands. The associated deformation is weaker than that of the Late Cretaceous event and spatially overlaps with it only in the Southern North Sea. Structural inversion of the SPB thus comprised only two events separated in time and mostly also in space.

Abstract A review of recent Triassic research across the Southern Permian Basin area demonstrates the role that high-resolution stratigraphic correlation has in identifying the main controls on sedimentary facies and, subsequently, the distribution of hydrocarbon reservoirs. The depositional and structural evolution of these sedimentary successions was the product of polyphase rifting controlled by antecedent structuration and halokinesis, fluctuating climate, and repeated marine flooding, leading to a wide range of reservoir types in a variety of structural configurations. Triassic hydrocarbon accumulations form an important energy resource across the basin, not only in the established Buntsandstein fairway but also in Rogenstein oolites and Muschelkalk carbonates. In addition, sand-prone sections in the Late Triassic, such as the Schilfsandstein, have the potential to be hydrocarbon reservoirs. Several Triassic intervals are now the focus for developing geothermal projects. A detailed understanding of Triassic reservoir quality and distribution is one of the main keys to efficiently unlocking the geothermal and remaining hydrocarbon potential across the basin.

Abstract Basin-scale stratigraphic correlation is the fundamental base for successful reservoir exploration, and especially when dealing with cross-border areas. Differences in lithostratigraphic and chronostratigraphic nomenclature between sub-basins and countries often result in problematic estimations of reservoir geometries and potential. This study combines available biostratigraphic, biofaunal and lithofacies data, together with sequence-stratigraphical correlations of the Lower Jurassic from the Central European Basin (CEB), to propose a genetic-based framework of transgressive and regressive depositional units. The determination of four major biofacies environments, composed of (I) polyhaline open-marine/offshore environments, (II) upper mesohaline marine–brackish environments, (III) lower mesohaline brackish environments and (IV) low oligohaline to freshwater continental environments comprising very rare marine phytoplankton and terrestrial spores and pollens, were translated into 12 biofacies reconstructions of ammonite (sub-) chronozone levels. Variations of biofacies reconstructions in time and space were supplemented by biostratigraphically constrained large-scale progradational and retrogradational sedimentary architecture. Retrogradation is accompanied by increasing polyhaline environments and pinpoint basinwide third-order flooding events, whereas progradation is accompanied by decreasing polyhaline environments pointing to third-order regressions. The outcomes of this study support exploration of Lower Jurassic deep geothermal reservoirs or CO 2 storage sites in the eastern CEB (especially Germany and Poland). Supplementary material: A list of all documented Liassic ammonites known from the eastern European shelf area (Denmark, The Netherlands, Sweden, Germany, Poland; wells and outcrops) is available at https://doi.org/10.6084/m9.figshare.c.3923467

Abstract A detailed 3D petroleum system model was constructed for the Schleswig-Holstein area in northern Germany. Salt movement and the Quaternary ice episodes were implemented in order to reconstruct their impact on temperature, maturity and pressure. Burial, temperature and maturity histories were calculated for the Jurassic troughs and the Glueckstadt Graben showing both differences and similarities. For example, all locations reached (almost) deepest burial at present day, whilst subsidence and long-term sedimentation rate was highest in Glueckstadt Graben during the Triassic. The Jurassic troughs received their major subsidence and sedimentation pulse later, and were strongly affected by a later salt movement. The implementation of Quaternary glacial episodes does not have a strong impact on petroleum generation from the major source rock (Lower Toarcian Posidonia Shale). In the case of the Posidonia Shale reaching the stage of petroleum expulsion (outside of the study area), the effect of ‘glacial pumping’(i.e. the development of high pore pressures during glaciation followed by expulsion and subsequent pressure release during deglaciation) can be deduced from the model. Petroleum accumulations in the reservoir layers (Dogger sandstones) are also seen to have been affected. This finding is of interest for exploration, as it might control petroleum composition, biodegradation and leakage through cap rocks.

Abstract A high-resolution three-dimensional (3D) numerical basin model, incorporating the eastern part of the Lower Saxony Basin (LSB), the Gifhorn Trough and parts of the southern Pompeckj Block, was built to reconstruct the thermal and structural evolution of this area. The estimation and calculation of the unconventional oil and gas resource density within the Posidonia Shale source-rock unit was the main objective of this study. Incorporating organic–geochemical data for the Posidonia Shale source-rock units, such as compositional petroleum generation kinetics data, allowed a more accurate prediction of hydrocarbon potential compared to large-scale models of the area, as well as a better prediction of bulk adsorption capacity and adsorbed gas content. For the accurate calculation of oil and gas contents within the source-rock lithologies, mineralogy and physical properties of the rocks, such as compressibility, sorption capacity and porosity, are important as well as organic matter quantity, quality and thermal maturity. These properties in turn are strongly dependent on the vastly different burial/uplift histories within the LSB, Gifhorn Trough and the Pompeckj Block. The Gifhorn Trough, large parts of the Pompeckj Block and the flanks of the LSB are interesting concerning the unconventional oil potential, with current source-rock maturities between 0.65% and 1.2% vitrinite reflectance. Central parts of the LSB and small parts of the Pompeckj Block show inherent unconventional gas potential. Methane adsorption capacity is influenced by the burial/uplift history of the basin, which stresses the importance of structural and geochemical interlocking in understanding unconventional hydrocarbon systems.

Eight climatic events can be distinguished in the Triassic–Jurassic (ca. 201 Ma) continental strata of Poland. These events are distinguished by kaolinite/illite ratio, chemical index of alteration (CIA), color of sediments, and palynomorphs. The first transition to wetter climate, evidenced by a shift from smectite- to kaolinite-dominated mudrocks, coincides with the earlier (“precursor”) Rhaetian negative δ 13 C org excursion, which means that the beginning of climate perturbations predates the oldest known Central Atlantic magmatic province flood basalts by some 100–200 k.y. The later global, late Rhaetian “initial” negative δ 13 C org excursion is divided into two subpeaks, each corresponding to hot and humid events, separated by a cooler and drier event. The upper subpeak is also associated with perturbation of the osmium isotope system (attributed to volcanic fallout), and darkened miospores, pointing to acid rains. Between the “initial” excursion and the Triassic-Jurassic boundary interval, five climatic fluctuations are inferred from the changing kaolinite/illite ratio, the last two of which are also associated with an Os isotope perturbation, polycyclic aromatic hydrocarbon (PAH) occurrences, a “spore peak,” and darkened miospores. A series of periodic atmospheric loading events by CO 2 , CH 4 , or alternatively by SO 2 , sulfate aerosols, and toxic compounds, is inferred to have caused this series of rapid climatic reversals and resulting extinction of many less-adapted forms. Just above the palynofloral extinction level, appearance of new forms commenced Jurassic palynofloral recovery. Tetrapod evolution events in the end-Triassic–earliest Jurassic were related to the extinction of the Pseudosuchia, Dicynodontia, Capitosauroidea, Plagiosaroidea, and Rhynchosauria, while appearance of highly diversified tetrapod ichnofauna in the earliest Jurassic strata indicates a rapid recovery and refill of ecological niches by dinosaurs.