Upper Carboniferous sedimentary cycles produced by river-dominated, elongate deltas

Coarsening upwards cycles in the upper Carboniferous Bideford Group of north Devon reflect the repeated progradation of riverdominated, elongate deltas. The cycles consist of progradational sequences (large-scale, prodelta to mouth bar coarsening upwards sequences, and major distributary channel sandstones), aggradational sequences (small-scale beach-spit coarsening upwards sequences and fining upwards crevasse channel sequences), and sporadically developed abandonment fades (thin, bioturbated siltstones and a coal horizon). Variations between cycles are governed principally by the location of bar fingers, and axial, lateral and (?) distal bar finger successions are distinguished.