Abstract Spatially and temporally variable Tournaisian to Namurian Carboniferous fluvial, fluvio-deltaic, platform carbonate and shale-dominated basin sedimentary successions up to 3.5 km thick are preserved in a complex series of basins from the Outer Moray Firth (Quadrant 14) to the Silverpit Basin (Quadrant 44). Differences in stratigraphic nomenclature in the areas surrounding the Mid North Sea High and onshore, combined with sparse biostratigraphic data, have hindered the systematic regional understanding of the timing and controls on stacked source and reservoir rock intervals. Over 125 well reinterpretations, tied to seismic interpretations, provide evidence of the inception and extent of a delta system. Regional time slices highlight a long-lived laterally equivalent basinal, mud-rich succession across Quadrants 41–44. They also show that the area from the Outer Moray Firth to the Silverpit Basin was part of the same sedimentary system up to at least Namurian times. All of this is placed within a simplified stratigraphic framework. Supplementary material: Appendix A in the Supplementary Material contains the stratigraphic intervals interpreted on each well and highlights which intervals have biostratigraphic control. Supplemental Figures 1 and 2 are larger scale versions of Figures 6 – 8 . The Supplementary Material is available at https://doi.org/10.6084/m9.figshare.c.4087046

Abstract Intrusive igneous rocks contributed very significantly to crustal growth in northern England and the English Midlands during Ordovician and Devonian times, and the buoyancy effect of these mainly granitic rocks beneath the Lake District, Cheviot Hills and the Askrigg and Alston areas of the north Pennines was to have a profound effect on the later development of Carboniferous and Permo-Triassic extensional basins in the region. During late Ordovician times voluminous subduction- related intrusive rocks were emplaced at the margin of Eastern Avalonia in a zone extending at least from Ireland, through the Lake District and the Midlands, to Belgium as a result of closure of the Iapetus Ocean and Tornquist Sea. By contrast, Early Devonian granitic plutons in northern England and the Southern Uplands belong to suites that were emplaced across the Iapetus suture zone, before, during and after the Acadian Orogeny. A similar sequence may be present in the Isle of Man. In the Lake District, the main components of a large, subvolcanic, granitic batholith (Fig. 7.1), along with a wide variety of minor intrusions, were emplaced contemporaneously with the Caradoc Eycott and Borrowdale volcanic groups (Millward 2002, 2004 and references therein). Some of the exposed intrusions are linked geochemically to the volcanic rocks, whereas others have distinctive geochemical signatures (e.g. O’Brien et al. 1985). To the SE, within the Askrigg Block and in central England, late Ordovician calc-alkaline intrusive and volcanic rocks comprise a relatively small number of exposures