The block and basin tectonostratigraphic framework for the northern Pennine (rift) Basin, within which buoyant granite intrusions core intra-basin fault-bounded blocks, has long held traction. However, many of the elements of this framework are rooted in primitive tectonic models and, perhaps unsurprisingly, corresponding depositional models often reflect this. Using sedimentological and sedimentary provenance approaches, the synrift (Mississippian) fluvio-deltaic Fell Sandstone Formation and age-equivalent strata within the northern Pennine Basin are examined. Highlighted divergences from classically depicted models relate to occurrences of pre-Carboniferous basement domes or monoclines, which are unbounded by major vertically displacing (>100 m) fault systems. Such structures in the northern Pennine Basin are all granite-cored and their origins are associated with their buoyancy and flexural isostatic processes. One such basement dome, the Cheviot Block, confined and deflected the Fell Sandstone fluvio-deltaic system from the west, causing locally elevated net sand content and variations in the dominant palaeodrainage direction. Central parts of the Alston Block, which forms a regional monocline along an east–west axis, were comparatively uplifted because of flexural isostatic responses to granite intrusions. The findings presented are at variance not only with classically depicted depositional models for the region, but also with more general depictions of dominantly normal fault-driven rift basin systems.
The British Geological Survey (BGS) is thanked for providing digital map, borehole information and 3D subsurface data for northern England. Further borehole data were supplied by the UK Oil and Gas Authority (OGA) via its data release agent IHS Markit. The National Trust and D. Armstrong of Murton Farm are thanked for granting access to their land. Geochemical (XRF) analysis was performed at Keele University, where D. Wilde also prepared thin-section samples. Seismic data were curated by the UK Onshore Geophysical Library (UKOGL). We would like to thank S. Boulton for her role as editor during the preparation of this paper, as well as G. Cole and R. Grant as reviewers. The contributions of A. Rotevatn, M. Booth, R. Jarrett, B. Barrett and anonymous reviewers to previous versions of this paper are also gratefully acknowledged. A. Regis and G. Meinhold of the Basin Dynamics Research Group (BDRG) at Keele University are also thanked for their contributions to this paper.
This study was conducted as part of a PhD supported by the Natural Environment Research Council (NERC) Centre for Doctoral Training (CDT) in Oil and Gas (grant number NEM00578X/1). It is sponsored by NERC, the Keele University Acorn Fund and the National Productivity Investment Fund (NPIF), whose support is gratefully acknowledged.