Sedimentation across a coastal plain to deep-water system: Insights from a Carboniferous succession, northern England

Documenting coeval sedimentary processes across continental to marine systems is challenging, especially in cases with poor preservation, uncertain correlations, and limited data. Outcrops of the Carboniferous Millstone Grit Group in Nidderdale, North Yorkshire, England, record mechanisms of sediment transport and deposition, and associated facies changes, across an ancient coastal plain to submarine ramp. The aim is to document controls on sedimentation from fluvial to deep-water systems via ramp-hosted deltas, and to determine why and how sediment is stored in each palaeoenvironment. Twenty-seven sedimentary logs (totalling ca. 470 m) were recorded from two correlated quarries and adjacent outcrops exposing a vertical rock unit of ∼160 m. Nineteen facies were identified and assigned to ten facies associations; integration with photo panels allowed interpretation of architectural elements and construction of depositional models. The following depositional environments were recognised: (i) mudstone-dominated offshore marine ramps intercalated with turbidites, (ii) heterolithic delta lobes, (iii) lower delta plains with distributary channels, (iv) upper delta plains, (v) alluvial plains with fluvial channel belts. The recognised architectural elements record relationships between coevally active and neighbouring depositional environments. Results demonstrate mechanisms of sediment transport across a sand-prone fluvial coastal plain, via a river-dominated delta, to a submarine ramp with turbidites. This model of sediment transport from continental to marine realms provides a predictive framework applicable to subsurface analogues to help predict the distribution of sedimentary facies, bounding surfaces, architectural changes, and stratigraphic evolution of depositional environments across a linked fluvio-deltaic to submarine systems in deltaic ramp settings.