Millstone Grit is the name given to any of a number of coarse-grained sandstones of Carboniferous age which occur in the British Isles. The name derives from its use in earlier times as a source of millstones for use principally in watermills. Geologists refer to the whole suite of rocks that encompass the individual limestone beds and the intervening mudstones as the Millstone Grit Group. The term Millstone Grit Series was formerly used to refer to the rocks now included within the Millstone Grit Group together with the underlying Edale Shale Group.
The Cheadle Coalfield is a coalfield in the United Kingdom. Centred on the town of Cheadle, Staffordshire and its outlying villages it lies to the east of Stoke-on-Trent and the much larger North Staffordshire Coalfield. The area has been mined for many years, with documentary evidence from Croxden Abbey citing coal mining in the 13th century.
The Durham Coalfield is a coalfield in north-east England. It is continuous with the Northumberland Coalfield to its north. It extends from Bishop Auckland in the south to the boundary with the county of Northumberland along the River Tyne in the north, beyond which is the Northumberland Coalfield.
The Northumberland Coalfield is a coalfield in north-east England. It is continuous with the Durham Coalfield to its south. It extends from Shilbottle in the north to the boundary with County Durham along the River Tyne in the south, beyond which is the Durham Coalfield.
The Cumberland Coalfield is a coalfield in Cumbria, north-west England. It extends from Whitehaven in the south to Maryport and Aspatria in the north.
The Leicestershire and South Derbyshire Coalfield in the English Midlands is one of the smaller British coalfields. The two areas are sometimes separately referred to as the South Derbyshire Coalfield and the Leicestershire Coalfield. All of the worked coal seams are contained within the Lower and Middle Coal Measures which are of Upper Carboniferous age.
The Machrihanish Coalfield is a coalfield on the Kintyre peninsula in southwest Scotland. It is one of the smallest British coalfields. With the exception of a thin coal beneath the Lyoncross Limestone in the overlying Upper Limestone Formation, all of the coal-bearing strata are found within the Limestone Coal Formation, a subdivision of the Clackmannan Group; all being strata of Namurian age. There are numerous seams of which the Main Coal is the principal one, being some 3 to 4m thick. A further, higher seam known as the Kilkivan Coal has also been worked. The full sequence is:
The Canonbie Coalfield is a small and largely concealed coalfield at Canonbie in the south of Scotland. Survey work in recent years revealed potentially economically workable reserves beneath a cover of New Red Sandstone rocks.
The Midgeholme Coalfield is a coalfield in Midgeholme, on the border of Cumbria with Northumberland in northern England. It is the largest of a series of small coalfields along the south side of the Tyne Valley and which are intermediate between the Northumberland and Durham Coalfields to the east and the Cumberland Coalfield to the west. Like the other small coalfields to its east, this small outlier of the Coal Measures at Midgeholme occurs on the Stublick-Ninety Fathom Fault System, a zone of faults defining the northern edge of the Alston Block otherwise known as the North Pennines. It is recorded that coal was being mined at Midgeholme in the early seventeenth century. In the 1830s coal trains were being hauled from Midgeholme Colliery along the Brampton Railway by Stephenson's Rocket. The early workings have left a legacy of spoil heaps, bell pits, shafts and adits. There is no current coal production. However in January 2014, Northumberland County Council gave planning permission for the open-cast extraction of 37,000 tonnes of coal at Halton Lea Gate. This may open the way for other applications to mine the coalfield. In 1990 a proposal to mine reserves of 60,000 tonnes of good-quality coal at Lambley, Northumberland was rejected, but the prospect for a successful application has now changed, since the Planning Inspector allowed the development to proceed at Halton Lea Gate on appeal.
The Manchester Coalfield is part of the South Lancashire Coalfield, the coal seams of which were laid down in the Carboniferous Period. Some easily accessible seams were worked on a small scale from the Middle Ages, and extensively from the beginning of the Industrial Revolution in the early 19th century until the last quarter of the 20th century. The Coal Measures lie above a bed of Millstone Grit and are interspersed with sandstones, mudstones, shales, and fireclays. The Lower Coal Measures occupy the high ground of the West Pennine Moors above Bolton and are not worked in the Manchester Coalfield. The most productive of the coal measures are the lower two thirds of the Middle Coal Measures where coal is mined from seams between the Worsley Four Foot and Arley mines. The deepest and most productive collieries were to the south of the coalfield. The coalfield is affected by the northwest to southeast aligned Pendleton Fault along the Irwell Valley and the Rossendale Valley anticline. The Coal Measures generally dip towards the south and west. Numerous other smaller faults affect the coalfield. The Upper Coal Measures are not worked in the Manchester Coalfield.
The Denbighshire Coalfield in the historic county of Denbighshire in north-east Wales is one of the smaller British coalfields. It extends from near Caergwrle in the north, southwards through Wrexham, Ruabon and Rhosllannerchrugog to Chirk in the south. A small part extends into Shropshire around Oswestry. Beyond Caergwrle the coal-bearing strata continue northwards as the Flintshire Coalfield. Together the two coalfields are known as the North Wales Coalfield.
The Warwickshire Coalfield extends between Warwick and Tamworth in the English Midlands. It is about 25 miles (40 km) from north to south and its width is around half that distance. Its western margin is defined by the 'Western Boundary Fault'. In the northeast it abuts against steeply dipping shales of Cambrian age. The larger part of the outcrop at the surface consists of the Warwickshire Group of largely coal-barren red beds. Until its closure in 2013, the Daw Mill mine near Arley within the coalfield, was Britain's biggest coal-producer in the 21st century.
The Bristol Coalfield is a geologically complex coalfield in the west of England. Comprising the coal-bearing rocks arranged around the Coalpit Heath Syncline and Kingsdown Anticline, it extends beneath the eastern parts of the city of Bristol and northwards through southern Gloucestershire. The coalfield is sometimes referred to together with the Somerset Coalfield, which lies to its south, as the Bristol and Somerset Coalfield. There are also two outlying coal-mining areas, the Severn Coalfield and the Nailsea Basin which are described below.
The Coal Measures Group is a lithostratigraphical term coined to refer to the coal-bearing succession of rock strata which occur in the United Kingdom within the Westphalian Stage of the Carboniferous Period. Other than in Northern Ireland the term is now obsolete in formal use and is replaced by the Pennine Coal Measures Group, Scottish Coal Measures Group and the South Wales Coal Measures Group for the three distinct depositional provinces of the British mainland.
The coal measures is a lithostratigraphical term for the coal-bearing part of the Upper Carboniferous System. In the United Kingdom, the Coal Measures Group consists of the Upper Coal Measures Formation, the Middle Coal Measures Formation and the Lower Coal Measures Formation. The group records the deposition of fluvio-deltaic sediments which consists mainly of clastic rocks interstratified with the beds of coal. In most places, the coal measures are underlain by coarser clastic sequences known as Millstone Grit, of Namurian age. The top of the coal measures may be marked by an unconformity, the overlying rocks being Permian or later in age. In some parts of Britain, however, the Coal Measures grade up into mainly coal-barren red beds of late Westphalian and possibly Stephanian age. Within the Pennine Basin these barren measures are now referred to as the Warwickshire Group, from the district where they achieve their thickest development.
The geology of Merseyside in northwest England largely consists of a faulted sequence of Carboniferous Coal Measures rocks overlain in the west by younger Triassic and Permian age sandstones and mudstones. Glaciation during the present Quaternary Period has left widespread glacial till as well as erosional landforms. Other post-glacial superficial deposits such as river and estuarine alluvium, peat and blown sand are abundant.
The Pennine Coal Measures Group is a lithostratigraphical term referring to the coal-bearing succession of rock strata which occur in the United Kingdom within the Westphalian Stage of the Carboniferous Period. In formal use, the term replaces the Coal Measures Group as applied to the succession of coal-bearing strata within the Pennine Basin which includes all of the coalfields of northern England and the English Midlands. It includes the largely concealed Canonbie Coalfield of southern Scotland and the coalfields of northeast Wales and the minor Anglesey coalfield. The sequence consists in the main of mudstones and siltstones together with numerous sandstones, the more significant ones of which are individually named. Some are laterally extensive, others are more restricted in their range. There are numerous coal seams, again with some being more laterally continuous than others. Those which were economically valuable were named though any individual seam may have attracted different names in different pits and different districts. Marine bands preserving distinctive and dateable marine fossils such as goniatites and brachiopods are widespread within the sequence and enable correlation to be made between sequences in one part of the basin and another and with other basins
The geology of County Durham in northeast England consists of a basement of Lower Palaeozoic rocks overlain by a varying thickness of Carboniferous and Permo-Triassic sedimentary rocks which dip generally eastwards towards the North Sea. These have been intruded by a pluton, sills and dykes at various times from the Devonian Period to the Palaeogene. The whole is overlain by a suite of unconsolidated deposits of Quaternary age arising from glaciation and from other processes operating during the post-glacial period to the present. The geological interest of the west of the county was recognised by the designation in 2003 of the North Pennines Area of Outstanding Natural Beauty as a European Geopark.
The South Wales Coal Measures Group is a lithostratigraphical term referring to the coal-bearing succession of rock strata which occur in South Wales within the Westphalian Stage of the Carboniferous Period. The Group name is also applied to rocks of similar age across southern England from the Bristol Coalfield east to the concealed Oxfordshire, Berkshire and Kent Coalfields. In formal use, the term replaces the earlier Coal Measures Group The Group comprises the:
The coal industry in Wales has played an important role in the Industrial Revolution. Coal mining in Wales expanded in the eighteenth century to provide fuel for the blast furnaces of the iron and copper industries that were expanding in southern Wales. The industry had reached large proportions by the end of that century, and then further expanded to supply steam-coal for the steam vessels that were beginning to trade around the world. The Cardiff Coal Exchange set the world price for steam-coal and Cardiff became a major coal-exporting port. The South Wales Coalfield was at its peak in 1913 and was one of the largest coalfields in the world. It remained the largest coalfield in Britain until 1925. The supply of coal dwindled, and pits closed in spite of a UK-wide strike against closures. The last deep mine in Wales, Tower Colliery, closed in 2008, after thirteen years as a co-operative owned by its miners.
