Abstract There was a shift away from, but not an abandonment of, mining and Dalradian topics after Gregory's January 1910 presidential address, towards geomorphological topics such as the origin of fjords, sea lochs, lakes and glacial deposits. In the summers of 1910 and 1912 he went to Spain, probably with Audrey, on holiday as no overt scientific account followed, but he included his coastal observations in Gregory (1913) . In August–September 1910 he visited Sweden in connection with the International Geological Congress, returning immediately to the BA Meeting in Sheffield. From 1910–13 he was President of the Scottish Ski Club ( Who Was Who , 3). In 1911 he was elected Dean of the Science Faculty (Senate minutes), presumably for three years, and he made a long holiday trip with Audrey to France, Italy and Dalmatia, returning through Germany. It was also in 1911 that Gregory became a member of the Athenaeum Club (Athenaeum records), probably in order to enjoy more comfortable accommodation and more congenial company during his visits to London. He remained a member until his death. In 1912, he led an expedition to Benguella (Angola). His movements during the summer of 1913 are uncertain. Audrey had three thimbles purchased in 1913 in Langres, France, which suggests she might have been there with Gregory; however, she sometimes went on summer painting holidays to the continent when Gregory was away. There is a letter in August 1914 from Gregory showing his concern about her getting out of France quickly at the

Abstract 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.

Abstract In analytical models of salt diapirism, the initial salt-layer thickness and the post-deformation spacing of salt structures are key parameters. Here, 3D seismic data from The Netherlands offshore has enabled these parameters to be measured over large areas which can then be compared with model predictions. Estimates of the original salt-layer thickness were obtained by spatially filtering present thickness, using filters with varied spatial scales that remove local effects. Loss of evaporite minerals by dissolution or erosion during exposure, cannot be ruled out and, as such, thicknesses are minima. Spacing estimates were derived in two dimensions by locating the minimum separation of lines representing ridgelines of diapirs/walls. Because the length scale of spatial filtering was chosen based on the dependent variable, diapir spacing, the results are non-unique. Nevertheless, choosing an apparently optimal filter length of 50 km, a ratio between diapir spacing and original thickness from 12 to 20 is defined. This ratio is greater than has been reported for the pillow province of the UK North Sea Quadrant 44, which is as expected if pillows evolve into diapirs with progressive halokinetic deformation. This work is key to understanding the evolution of salt displacement, a necessity for unlocking remaining hydrocarbon resources.