Abstract Carboniferous rocks within this region occur in a series of inliers, many occurring in the cores of periclines and anticlines. The Tournaisian and Visean strata comprise ramp carbonate successions (Avon and Pembroke Limestone groups), which show similarities with equivalent strata to the west in South Wales (Chapter 5). The main outcrops, broadly from south to north, are the Cannington Park inlier and Mendips, Weston-super-Mare, Broadfield Down, Bristol and Avon, Cromhall and Chepstow to Monmouth (Fig. 19). Namurian strata are present only in the south of the region, in the Bristol and Somerset coalfields. Little information is available on the nature of these strata, though they show some similarities to the fluvial and deltaic successions of the Marros Group of South Wales (Chapter 5). Westphalian strata are present in all the coalfields, broadly from south to north, the Somerset, Bristol, Severn, Forest of Dean and Newent coalfields (Fig. 19). Fluvio-lacustrine deposits (South Wales Coal Measures Group) are present only in the Somerset, Bristol and the south-eastern part of the Nailsea coalfields. These coalfields are laterally contiguous beneath Mesozoic strata. Deposition was also probably laterally contiguous with the concealed Berkshire Coalfield (Chapter 7). It has not been possible to demonstrate lateral continuity with the South Wales Coalfield (Chapter 5). Strata of this facies are absent from the Newent, Forest of Dean and Severn coalfields and the Cannington Park inlier along the axis of the syn-Westphalian Usk Anticline.

Abstract The term Carboniferous was created as a stratigraphical term by Conybeare & Phillips (1822) for strata present in England and Wales and was first referred to as a system by Phillips (1835). The original definition of the Carboniferous included the Old Red Sandstone. With the establishment of the Devonian system in 1839 the Old Red Sandstone was removed from the Carboniferous and placed in the Devonian. Broad similarities within the successions of Britain and Ireland with the rest of Western Europe have allowed development of a regionally applicable chronostratigraphy. Munier-Chalmas & de Lapparent (1893) originally divided the Carboniferous of Western Europe into the Dinantian, Westphalian and Stephanian. Later, the lower part of the Westphalian was redefined as the Namurian and both were identified as stages (Jongmans 1928). The Namurian, Westphalian and Stephanian stages do not represent global faunal or fioral events, but were chosen to represent prominent facies variations and palaeogeographic separations in Western Europe. The Dinantian subsequently became a subsystem, with two component series, the Tournaisian and Visean (George & Wagner 1972), whereas the Namurian, Westphalian and Stephanian became series of a Silesian Subsystem. However, George et al. (1976) were not prepared to use the terms Tournaisian and Visean in their review of British chronostratigraphy.

Abstract Carboniferous rocks within the Cumbria and northern Pennines region are bound by the Maryport-Stublick-Ninety Fathom Fault System, which forms the northern boundary of the Lake District and Alston blocks (Fig. 37). In the Pennines, the succession occupies the Alston and Askrigg blocks and the intervening Stainmore Trough, a broadly east-west trending graben. Carboniferous strata also flank the Lake District Block, occurring at outcrop in north Cumbria, Furness and Cartmel (south Cumbria) and the Vale of Eden, and in the subsurface in west Cumbria. The Askrigg Block succession is separated from that of the Craven Basin (Chapter 11), to the south, by the Craven Fault System. All of the stages of the Carboniferous, with the exception of the Stephanian, are present at outcrop. The oldest Tournaisian strata occur at outcrop along the flanks of the Lake District Block and within the Stainmore Trough. They are represented by continental and peritidal deposits (Ravenstonedale Group), and locally associated with volcanic rocks (Cockermouth Volcanic Formation of north Cumbria). The Ravenstonedale Group is diachronous, occurring later on the structural highs, with deposition during Chadian times on the Askrigg Block and Holkerian times on the Alston Block. The Ravenstonedale Group is overlain by upper Tournaisian to upper Visean platform carbonate rocks (Great Scar Limestone Group), which initially developed on the flanks of the Lake District Block, but by late Asbian times extended across the entire region (Mitchell 1978).

Abstract Carboniferous strata within this region occur in the broad eastern flank of the north-south axis of the Clwydian Range from Prestatyn to Oswestry, sections within the Vale of Clwyd and the outlying districts around Llandudno, Menai Straits and Anglesey (Fig. 25). In NE Wales and the Welsh Borderlands the gently tilted Visean limestones are succeeded to the east by Namurian to Westphalian strata forming the Flint and Denbigh coalfields. This region includes intermittent development of Tournaisian to Visean alluvial deposits (‘Basement Beds’). These are overlain by Visean ramp-to-shelf carbonates, present along the northern margin of the Wales-Brabant High, extending across North Wales (Clwyd Limestone Group). Visean to Namurian basinal deposits (Craven Group) occur on the north coast of North Wales (Fig. 25), deposited on the southern margin of the Irish Sea Basin (see Chapter 16). During the Namurian and Westphalian this region is represented by thick fluvio-deltaic successions, including the Millstone Grit and Pennine Coal Measures groups, in turn overlain by alluvial deposits of the Warwickshire Group.

Abstract Carboniferous rocks within this area occupy the region to the south of, and contiguous with, the Southern Pennines (see Chapter 11). The oldest Tournaisian and Visean strata occur at outcrop within the Peak District, represented by ramp-to-shelf carbonates (Peak Limestone Group) deposited on the Derbyshire High, a promontory of the East Midlands Shelf, and the laterally extensive Staffordshire and Hathern shelves. The platform carbonates of the East Midlands Shelf extend in the subsurface below Nottinghamshire and Lincolnshire, where the nature of the succession is based largely upon well records and geophysical information (Strank 1987). A 23 m thick succession of platform carbonates is recorded in the base of the Saltfleet by No. 3 Borehole [TF 4246 9135] (Hodge 2003) and at least 100 m is present in the Welton Oil-field (Fig. 31). The Derbyshire High platform carbonate rocks pass into more basinal successions in the Edale Basin to the north, the Widmerpool Gulf to the south and the Staffordshire Basin to the west, dominated by hemi-pelagic mudstone and carbonate turbidites (Craven Group). The lithostratigraphical nomenclature for the Tournaisian and Visean strata is that of Waters et al. (2009), adapted from Aitkenhead & Chisholm (1982).

Abstract We present an updated look at Carboniferous brachiopod biozonation from most of the world framed into a revised Carboniferous palaeogeography, based on a selection of the literature published on Carboniferous brachiopods since the nineteenth century. The biostratigraphic significance of the most important brachiopod taxa is synthesized in seven geographical correlations. The Mississippian is characterized by rich brachiopod faunas, with widespread taxa with a good potential for global correlation, such as Rugosochonetes , Delepinea , Buxtonia , Antiquatonia , Spinocarinifera , Marginatia , Fluctuaria , Ovatia , Rhipidomella , Lamellosathyris , Unispirifer , Tylothyris and Syringothyris . From the mid-Visean to the late Serpukhovian, taxa of gigantoproductidines are biostratigraphically significant, and occur everywhere except South America and Australia, which remain as distinct faunal successions for most of the period. A major turnover occurs at the beginning of the Pennsylvanian, characterized by a higher degree of provincialism. Pennsylvanian brachiopod faunas are diverse in China, Russia and North America, but otherwise they are less developed and are characterized mostly by endemic taxa, hampering long-distance correlation. An exception is the rapid diversification of taxa of the Choristitinae, which were widespread from the Bashkirian to the Moscovian, allowing long-distance correlation.

Abstract The structural evolution of England and Wales during the Carboniferous was primarily a consequence of an oblique (dextral) collision between Gondwana and Laurussia ( Warr 2000 ). Several phases can be recognized. The Rhenohercynian Ocean opened during Early–Mid Devonian regional bacK–Arc transtension between Avalonia and Armorica ( Fig. 9.1 ), possibly associated with northward-directed subduction along the southern margin of Armorica. A narrow seaway floored by oceanic crust developed, extending across southwest England, northern France and Germany. Cessation of the subduction, associated with the Ligerian orogenic phase of central Europe, resulted from the collision of the Iberian and Armorican microplates ( Fig. 9.1 ). During the Late Devonian, transpressive closure of this restricted ocean, associated with the Bretonian orogenic phase, may have occurred in response to short-lived southward-directed subduction of the Rhenohercynian oceanic plate beneath Armorica. A return to northward-directed subduction of the Theic oceanic plate along the southern margin of Iberia/Armorica ( Fig. 9.1 ) resulted in a Late Devonian–Early Carboniferous phase of bacK–Arc extension within the Avalonian part of the Laurussian plate ( Warr 2000 ). The resultant N–S rifting affected all of central and northern England and North Wales, initiating development of a series of graben and half-grabens,