Sedimentology of a Devonian fault-bounded braidplain and lacustrine fill in the lower part of the Skrinkle Sandstones, Dyfed, Wales

摘要: The Upper Devonian to Lower Carboniferous Skrinkle Sandstones of the Pembroke Peninsula are predominantly continental deposits from post-Caledonian synrift succession at southern margin Palaeozoic Welsh Landmass. lower part record deposition in 30 × 10 km Tenby–Angle fault block, which a 6- 68-m-thick interval is described and interpreted as lacustrine deposit succeeded by high-energy sandy braidplain succession. dominated red mudstones ripple cross-laminated sandstones. Interbedded quartzose sandstones form coarsening-upward sequence basin centre, suggesting deltaic origin, smooth-fronted delta model proposed. introduces succession, composed groups horizontal/low-angle laminated trough cross-bedded These compared with recent ephemeral stream sheetflood sediments their characteristics used depict system mutually erosive channel bodies, latter produced during rising falling stages flood events, alternate produce thick multistorey sandstone. Palaeocurrent data indicate an axial drainage north-west, running parallel main faults area. This supported maturity nature sediments. Basin closure towards south postulated Bristol Channel Landmass inferred.