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This volume offers an up-to-date ‘geology-without-borders’ view of the stratigraphy, sedimentology, tectonics and oil-and-gas exploration trends of the entire Atlantic Margin and Barents Sea basin. The challenges associated with data continuity and nomenclature differences across median lines are discussed and mitigated. Examples of under-exploited cross-border plays and discoveries are discussed.

A cross-border approach to exploration, appraisal and development is important in mature basins such as the North Sea, where the ‘low hanging fruit’ have long gone. This approach emphasizes the need to see the basin as one geological entity, in order to maximize economic recovery and prepare the area for the energy transition. This volume offers an up-to-date, ‘geology-without-borders’ view of the stratigraphy, sedimentology, tectonics and oil-and-gas exploration trends of the entire North Sea basin, along with the challenges associated with differences in data continuity and nomenclature across median lines. This volume includes overviews of cross-border play statistics, lithostratigraphic naming conventions and exploration performance through to new facies models for cross-border areas. As such, this volume will be a valuable reference for every geoscientist working in the North Sea for years to come.

As geological information about the North Sea is increasingly made available to the public, there is great potential to build cross-border datasets to enable people to more rapidly filter relevant geological data and also to better understand and further study the subsurface. This paper discusses the construction of such a geological database and presents the associated map set. Public domain lithostratigraphic data from petroleum exploration and appraisal wells drilled in the Norwegian, Danish, German, Dutch and UK North Sea sectors were used to create a series of 13 well-penetration maps, ranging from Basement to Eocene age. In order to produce the maps, lithostratigraphic well tops had to be translated into a chronostratigraphic scheme, followed by building a database and subsequent mapping in a GIS. Three well categories were used for each of the maps: wells that (1) fully penetrate a chronostratigraphic interval, (2) prove it is absent or (3) reach total depth in the interval under consideration. The resulting maps, which will all be discussed and presented in this paper, form a starting point for multiple types of (petroleum) geological screening studies. The North Sea database is freely available in QGIS format and can be easily imported into any geospatial software platform.

The Southern North Sea Basin area, stretching from the UK to the Netherlands, has a rich hydrocarbon exploration and production history. The past, present and expected future hydrocarbon and geothermal exploration trends in this area are discussed for eight key lithostratigraphic intervals, ranging from the Lower Carboniferous to Cenozoic. In the period between 2007 and 2017, a total of 95 new hydrocarbon fields were discovered, particularly in Upper Carboniferous, Rotliegend and Triassic reservoirs. Nineteen geothermal systems were discovered in the Netherlands onshore, mainly targeting aquifers in the Rotliegend and Upper Jurassic/Lower Cretaceous formations. Although the Southern North Sea Basin area is mature in terms of hydrocarbon exploration, it is shown that with existing and new geological insights, additional energy resources are still being proven in new plays such as the basal Upper Rotliegend (Ruby discovery) for natural gas and a new Chalk play for oil. It is predicted that hydrocarbon exploration in the Southern North Sea Basin area will probably experience a slight growth in the coming decade before slowing down, as the energy transition further matures. Geothermal exploration is expected to continue growing in the Netherlands onshore as well as gain more momentum in the UK.

Fungi defend their ecological niche against antagonists by producing antibiosis molecules. Some of these molecules are only produced upon confrontation with the antagonist. The basidiomycete Coprinopsis cinerea induces the expression of the sesquiterpene synthase-encoding gene cop6 and its two neighboring genes coding for cytochrome P450 monooxygenases in response to bacteria. We further investigated this regulation of cop6 and examined if the gene product is involved in the production of antibacterials. Cell-free supernatants of axenic cultures of the Gram-positive bacterium Bacillus subtilis were sufficient to induce cop6 transcription assessed using a fluorescent reporter strain. Use of this strain in a microfluidic device revealed that the cop6 gene was induced in all hyphae directly exposed to the supernatant and that induction occurred within less than one hour. Targeted replacement of the cop6 gene demonstrated the requirement of the encoded synthase for the biosynthesis of the sesquiterpene lagopodin B, a previously reported antibacterial compound from related species. Accordingly, lagopodin B from C. cinerea inhibited the growth of several Gram-positive bacteria including B. subtilis but not Gram-negative bacteria. Our results demonstrate that the C. cinerea vegetative mycelium responds to soluble compounds of a bacterial culture supernatant by local production of an antibacterial secondary metabolite.