Related Research Articles
The geological structure of Great Britain is complex, resulting as it does from a long and varied geological history spanning more than two billion years. This piece of the Earth's crust has experienced several episodes of mountain building or 'orogenies', each of which has added further complexity to the picture.
In geology, a disturbance is a linear zone of disturbed rock strata stretching for many miles across country which comprises a combination of folding and faulting. The British Geological Survey record a number of such features in South Wales including the Neath Disturbance, Pontyclerc Disturbance, Carreg Cennen Disturbance and the Cribarth Disturbance, the latter sometimes also known as the Tawe Valley or Swansea Valley Disturbance. The southwestward continuation of the Carreg Cennen Disturbance is known as the Llandyfaelog Disturbance.
The Bronnant Fault is a geological fault affecting the lower Palaeozoic rocks of the counties of Ceredigion and Pembrokeshire in West Wales. The feature is mapped over part of its length as the Bronnant Fault Zone and is closely associated with the Glandyfi Lineament, a similarly aligned zone of faulting and folding. The rocks of the Aberystwyth Grits Group dating from the Llandovery epoch of the Silurian period thicken markedly to the west of the fault suggesting it was active at the time of their deposition. North of Lledrod its alignment is affected by cross-cutting east–west faults, including the Ystwyth Fault Zone. Its alignment is sub-parallel to the coast of Cardigan Bay thus curving from a north–south alignment in the north through a northeast–southwest alignment until it merges with broadly east–west aligned faults in northeast Pembrokeshire.
The Flintshire Coalfield in north-east Wales is one of the smaller British coalfields. It is in the county of Flintshire and extends from the Point of Ayr in the north, along the Dee Estuary through Connah's Quay to Caergwrle in the south. A small part extends onto the Wirral i.e. English coast of the estuary at Neston, Cheshire which was the site of a coalmine for a period. The coal-bearing strata continue southwards of Caergwrle as the Denbighshire Coalfield. Together the two coalfields are known as the North Wales 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 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 Sherwood Sandstone Group is a Triassic lithostratigraphic group which is widespread in Britain, especially in the English Midlands. The name is derived from Sherwood Forest in Nottinghamshire which is underlain by rocks of this age. It has economic importance as the reservoir of the Morecambe Bay gas field, the second largest gas field in the UK.
The Gwna Group is a late Precambrian (Ediacaran) / Cambrian lithostratigraphic group in northwest Wales. The name is derived from the Afon Gwna, a river near Bodorgan on Anglesey where the strata are exposed. This rock sequence is also commonly referred to as the Gwna Mélange.
The Portsdown Anticline is a north-facing geological fold of Tertiary age affecting rocks in Hampshire, southern England. This upfold of the local sedimentary rock sequence is paralleled by the Bere Forest/Chichester Syncline (downfold) about 2km to its north and a postulated deep fault to the north again. Further west, this major east-west structure adopts more of a NW - SE alignment. At the surface the Portsdown Anticline is seen to affect the Chalk rocks of Late Cretaceous age at Ports Down though it is known to also affect the underlying Jurassic strata.
The Exmoor Group is a late Devonian to early Carboniferous lithostratigraphic group in southwest England whose outcrop extends from Croyde in north Devon east across Exmoor to Minehead in west Somerset. The group comprises the following formations the:
The geology of Northumberland in northeast England includes a mix of sedimentary, intrusive and extrusive igneous rocks from the Palaeozoic and Cenozoic eras. Devonian age volcanic rocks and a granite pluton form the Cheviot massif. The geology of the rest of the county is characterised largely by a thick sequence of sedimentary rocks of Carboniferous age. These are intruded by both Permian and Palaeogene dykes and sills and the whole is overlain by unconsolidated sediments from the last ice age and the post-glacial period. The Whin Sill makes a significant impact on Northumberland's character and the former working of the Northumberland Coalfield significantly influenced the development of the county's economy. The county's geology contributes to a series of significant landscape features around which the Northumberland National Park was designated.
This article describes the geology of the Broads, an area of East Anglia in eastern England characterised by rivers, marshes and shallow lakes (‘broads’). The Broads is designated as a protected landscape with ‘status equivalent to a national park’.
References
Maps
- 1:625,000 scale geological map 2007, Bedrock Geology UK South, British Geological Survey, Keyworth, Notts (UK (south) 625K)
- 1:250,000 scale geological map Mid Wales and the Marches, British Geological Survey, Keyworth, Notts (MW & M 250K)
- 1:63,360 scale geological map Bristol Special sheet, British Geological Survey, Keyworth, Notts (Bristol Special 1" .)
- various of 1:50,000 scale geological maps of England and Wales, British Geological Survey, Keyworth, Notts (E & W no.)
- 1:25,000 scale sheet Church Stretton in Classic Areas of British geology series, British Geological Survey, Keyworth, Notts (Ch Stret: 25K)
Books
- Barton et al. 2011. Geology of South Dorset and South-east Devon and its World Heritage Coast, Special Memoir of the British Geological Survey (Mem E&W 328etc)
- Brenchley, P.J. & Rawson, P.F. (eds) 2006. The Geology of England and Wales, (2nd edn) The Geological Society, London (Brenchley & Rawson 2006)
- Cope, J.C.W. 2012 GA Guide no 22: Geology of the Dorset Coast, The Geologists' Association ISBN 9780900717611 (GA Guide22)
- Hamblin, R.J.O. & Coppack, B.C., 1995 Geology of Telford and the Coalbrookdale Coalfield, Memoir of the British Geological Survey, parts of sheets 152 & 153 (England and Wales), HMSO (Mem (E&W 152/153)
- Smith et al. 2005 Structure & Evolution of the south-west Pennine Basin and adjacent area. Subsurface memoir of the British Geological Survey. (Smith et al. 2005)
- Toghill, P. 2006 Geology of Shropshire (2nd edn) Crowood Press, Wilts (Toghill P 2006)
- Webby, B.D. 1965 Proceedings of the Geologists' Association volume 76, part 1 (Webby, B.D. 1965)
- Welch, F.B.A. & Trotter, F.M. 1961 Geology of the Country around Monmouth and Chepstow, HMSO (explanation of 1" geol. sheets 233 & 250 (England and Wales) (Welch, FBA & Trotter, FM 1961)
- British Regional Geology: Northern England (BGS:BRG7)
- British Regional Geology: The Pennines & adjacent areas (BGS:BRG8)
- British Regional Geology: Eastern England from the Tees to The Wash (BGS:BRG9)
- British Regional Geology: Central England (BGS:BRG10)
- Earp, J.R. & Hains, B.A. 1971 British Regional Geology: The Welsh Borderland (3rd edn), London, HMSO for British Geological Survey (BGS:BRG11)
- Melville, R.V. & Freshney, E.C. 1982 British Regional Geology: The Hampshire Basin and adjoining areas (4th edn). London HMSO for the British Geological Survey (BGS:BRG15)
- British Regional Geology: Bristol & Gloucester District (BGS:BRG16)
- A Guide to the Geology of Martley (prepared for Teme Valley Geological Society by Herefordshire & Worcs Earth Heritage Trust) (Guide Geol. of Martley)