Mines with Sedimentary Beds and Seams

471 linked mines · Geology: Sedimentary Beds and Seams

Listed only where MineArchive's own research gives a reasonable evidential basis for the connection — not every mine where this geology might plausibly apply.

Mine	Region	Worked	Commodities	Connection
Aber Quarry	Anglesey	No reliable opening date has yet been located.–Still worked	Limestone	(well documented example) The quarry works the Carboniferous limestone that runs south from Lligwy Bay and Pentraeth across Anglesey, here the hard grey variety.
Aberaman Colliery	Rhondda Cynon Taf	1843–23 November 1962	Coal	(well documented example) Aberaman worked the bedded steam coals of the South Wales coalfield in the Aberdare valley, the seams that turned the district from iron to coal in the 1840s.
Aberbeeg Colliery	Blaenau Gwent	Sunk about 1860–Abandoned 19 April 1929	Coal	(well documented example) The Brithdir or Tillery seam worked at Aberbeeg is a bed in the South Wales coal measures, displaced here by the Llanhilleth fault.
Abercrave Colliery	Powys	1872–March 1967	Coal	(historical documentary reference) The Eighteen Foot, Four Feet, Nine Feet, Peacock and Lower Measures anthracite seams are named.
Abercwmboi Colliery	Rhondda Cynon Taf	1851 (working by 1828 on one account)–1962	Coal	(well documented example) Eight named seams from the Graig down to the Gellideg, with the Clay seam's fireclay; type 201B dry steam coal.
Abercynon Colliery	Rhondda Cynon Taf	July 1896–1988	Coal	(well documented example) Sunk to the Nine Feet seam and working in turn the Six Feet, Nine Feet, Upper Four Feet, Seven Feet and Five Feet — the named seam succession of the South Wales coalfield.
Abergorki Colliery	Rhondda Cynon Taf	1859–1938	Coal	(well documented example) Rhondda steam coals outcropping high on the valley side, reachable by level at Abergorki where the neighbouring Parc and Dare pits had to sink hundreds of feet for the same succession.
Addis Hill Colliery	Gloucestershire	By 1841–1935	Coal	(well documented example) The Coleford High Delf, between eighteen inches and six feet six thick here, with the Brazilly of the Supra-Pennant possibly worked above it.
Aislaby Quarry	North Yorkshire	By the 11th century–Still worked	Sandstone	(well documented example) The quarries work the Saltwick Formation of the Middle Jurassic Ravenscar Group, deltaic sandstones forming laterally impersistent beds and crags along the moorland escarpment.
Aitkenhead Colliery	Glasgow	Returned from 1894; working by 1874–Returned to 1915; siding closed 1918	Coal	(well documented example) Bedded Coal Measures seams of the Central Scottish coalfield beneath the south side of Glasgow.
Alvecote Colliery	Warwickshire	1875–1942 (coal winding); shafts abandoned 1965	Coal	(well documented example) The record describes the Seven Feet, Double and Bench seams of the Warwickshire Coalfield being worked in turn, and the subsidence caused by working several seams beneath the same ground.
Amberley Chalk Pits	West Sussex	1840s–1960s	Chalk, Limestone	(well documented example) Chalk — a very pure bedded limestone — quarried where the Arun breaches the Downs, and burnt on the spot because its purity is what makes good lime.
Amington Colliery	Staffordshire	1862–1951 (coal winding); shafts abandoned 1965	Coal, Fireclay	(well documented example) The record turns on the exhaustion of the Seven Feet seam beneath the colliery and the deepening of the shafts by 109 feet to reach the Bench seam below it, with fireclay worked alongside the coal.
Annesley Colliery	Nottinghamshire	1867–January 2000	Coal	(well documented example) A classic worked-down succession of bedded coals — Top Hard, Deep Hard, Deep Soft, Tupton, Thick Black Shale — each taken in turn as the one above was exhausted or became too difficult.
Ansley Hall Colliery	Warwickshire	1874–1959	Coal	(well documented example) The Two Yard and Bare coals worked out within nine years of sinking, after which everything came from inclined headings driven down the dip into the same beds.
Anson Colliery	Cheshire	1890–1926	Coal	(well documented example) The Accommodation, Gees, Reform and Red-acre seams worked at Anson are beds in the small Cheshire coalfield at Poynton.
Applethwaite Fell Slate Works	Cumbria	Working by 1888–No reliable closure date has yet been located.	Slate	(historical documentary reference) A green-slate quarry in the cleaved volcanic tuffs of the Borrowdale Volcanic Group, worked along an imposed cleavage rather than the original ash bedding, as this record's geology describes.
Arkwright Colliery	Derbyshire	1938–April 1988	Coal	(well documented example) Drifts driven in the Top Hard where the Brimington anticline brings the seam near the surface; later worked the Sitwell, Waterloo, Second Ell and Low Main seams.
Ashton's Field Colliery	Greater Manchester	1860s–Late 1920s (coal winding); pumping station to at least 1954	Coal, Cannel Coal	(well documented example) The record names the Cannel, Plodder, Trencherbone and Yard mines of the Lancashire Coal Measures worked in turn, narrowing to the Plodder by 1905.
Auchengeich Colliery	North Lanarkshire	1908–1965	Coal	(well documented example) Worked the Limestone Coal Formation — Carboniferous cyclic sediments in which workable coal seams alternate with limestones and mudstones, and which give off methane freely as they are cut.
Auchinreoch Colliery	East Dunbartonshire	Sinking in 1900–Idle by 1937; no closure date located	Coal	(well documented example) Bedded Coal Measures seams of the Central Scottish coalfield — the Coking, Haughrig and Wee seams.
Auckland Park Colliery	County Durham	1864–1946	Coal, Fireclay	(well documented example) Whellan's 1894 Directory gives the colliery's two principal bedded seams with their thicknesses and depths — the Harvey at 110 fathoms and the Brockwell at 150 — within the Durham Coal Measures sequence.
Auldhouseburn Colliery	East Ayrshire	By 1873, probably from c. 1871–1911	Coal	(well documented example) Bedded Coal Measures seams: a three-foot cannel and a four-foot ordinary coal lying together with only a stone band between them, worked as a single seven-foot seam.
Avenue Colliery	Derbyshire	1881 (Old Avenue 1857)–No reliable closure date has yet been located.	Coal	(well documented example) The No. 9 pit of 1881 was Clay Cross's Blackshale pit, working the deep seam whose abandoned workings later flooded into Williamthorpe's Second Piper.
Aysdalegate Mine	North Yorkshire	Held from 1863; production 1877–Production ended 1880	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Baddesley Colliery	Warwickshire	Sunk from May 1850–1989	Coal	(well documented example) A concealed-coalfield pit working flat-lying Coal Measures seams — the Two Yard (Ryder) for its first century, then the Nine Feet, Seven Feet and Bench — and forced down the dip after 1876 as the shallower reserves in the Ryder ran out.
Balgonie Colliery	Fife	Sinking 1883–1885–1960	Coal, Brick Clay, Mudstone	(well documented example) The record turns on coal, clay and blaes — oil shale — being returned as products of the same colliery in the Fife coalfield, the clay feeding its own brickworks.
Ballochmyle Colliery	East Ayrshire	Working by 1880–No reliable closure date has yet been located.	Coal	(historical documentary reference) A colliery on the Carboniferous Coal Measures of the Ayrshire coalfield, working coal as bedded seams within a faulted sedimentary sequence, as this record's geology describes.
Bamfurlong Colliery	Greater Manchester	By 1861–1936	Coal, Cannel Coal	(well documented example) The record lists the Pemberton, Ince, Wigan and Arley seams worked pit by pit, and turns on the quicksand near the surface that forced cast-iron tubbing into the Nos. 3 and 4 shafts.
Bank Hall Colliery	Lancashire	1869–17 April 1971	Coal	(well documented example) Worked the named Burnley coalfield seams in succession — Arley, King, Dandy or Upper Arley, and the Union formed by the merger of the Upper Foot and true Lower Mountain mines.
Bankton Colliery	East Lothian	Returned from 1905; the parish worked coal from the 13th century–Coal about 1927; pumping into the 1950s	Coal	(well documented example) The colliery worked the Jewel, Splint, Three Feet, Four Feet and Diamond seams of the East Lothian coalfield around Tranent.
Barnsley Main Colliery	South Yorkshire	Shown on the 1892 map as part of Rylands Main–1991	Coal	(well documented example) The colliery worked the Coal Measures of the South Yorkshire coalfield, No. 2 Shaft reaching the Barnsley Main Seam and, from 1916, the Fenton Seam beneath it.
Bartonholm Colliery	North Ayrshire	By 1871–1920 (discontinued); working again into the 1920s	Coal	(well documented example) The record names the Ell, Main and Turf coals of the Ayrshire Coalfield as the seams worked, and turns on ground wet enough that a neighbouring pit was kept purely for pumping.
Bathville Colliery	West Lothian	By 1859–After 1902	Coal, Fireclay	(well documented example) West Lothian Coal Measures whose fireclay seatearths came up with the coal and supported a firebrick industry on the same site for more than a century.
Bayton Colliery	Worcestershire	By the 18th century–No reliable closure date has yet been located.	Coal	(well documented example) Bayton worked the sulphur coal of the Wyre Forest coalfield's southern basin, a bedded Coal Measures seam whose sulphur content decided what the coal could be used for.
Beaufort Iron Works	Blaenau Gwent	1779–Between 1873 and 1877	Iron, Coal, Limestone	(well documented example) A heads-of-the-valleys works sitting on the northern outcrop of the South Wales Coalfield, taking both its fuel and its ore from the same Coal Measures sequence — coal and ironstone in unnamed veins, as the abandonment plan puts it — and importing only its limestone flux.
Bedford Colliery	Greater Manchester	1876–1967	Coal	(well documented example) Worked the Middle Coal Measures seams between the Worsley Four Foot and the Arley — Crombouke, Six Foot, Seven Foot, Trencherbone and Arley — the shafts being deepened seam by seam as the colliery followed the succession downwards.
Bedlinog Colliery	Merthyr Tydfil	Sunk 1878; first coal 1881–1956	Coal	(well documented example) The record names the Rhas Las, Bottom Rhas Las, Upper Four Feet and Little Vein seams of the northern outcrop of the South Wales coalfield, worked in turn.
Bedwas Navigation Colliery	Caerphilly	1912–May 1985	Coal	(well documented example) Sunk through the Mynyddislwyn seam to the Rhas Las or Black Vein and on by cross-measure to the Hard Vein, later the Lower Black Vein — a named succession of South Wales seams whose disturbed state at depth dictated the colliery's fortunes and finally its closure.
Belmont Mine	North Yorkshire	Leased 1853; production from 1855–Production ended 1921; lease to 1931	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Benallt Mine	Gwynedd	1886–December 1945	Manganese	(well documented example) The Llŷn manganese is a bedded ore within an Ordovician sedimentary and volcanic sequence, not a vein — so the workings follow an ore horizon across the headland rather than a lode downwards.
Benbain Colliery	East Ayrshire	By 1894–No reliable closure date has yet been located.	Coal	(historical documentary reference) Scoped honestly to the district: the record establishes that Benbain worked Doon valley coals for the Dalmellington furnaces, but the Lists of Mines name no seam and no source read here does either.
Benhar Colliery	West Lothian	Recorded working in 1818–No reliable closure date has yet been located.	Coal	(well documented example) Shallow bedded Coal Measures seams, one of them fifteen inches thick at eight fathoms in the 1818 record.
Bent Colliery	South Lanarkshire	By 1872–No reliable closure date has yet been located	Coal	(well documented example) Seven named seams of the Lanarkshire Coal Measures are recorded in the pit's returns between 1910 and 1925.
Bettisfield Colliery	Flintshire	1872–c. 1934	Coal	(well documented example) The record names the One, Two and Three Yard seams with the Queen and Five Feet, worked from two shafts sunk 290 yards at the Flintshire end of the North Wales coalfield.
Betws Colliery	Carmarthenshire	development from 1974–June 2003	Coal	(well documented example) The mine's own recorded geology explicitly describes Carboniferous anthracite coal seams of the South Wales Coalfield.
Bideford Black Mine	Devon	By the 13th century (pigment); commercial mining from the 1760s–1969	Mineral Black, Coal	(well documented example) Two thin bedded seams in the Culm Measures, the northern one occurring as discontinuous lenses rather than a persistent bed — which is exactly why working here was always sporadic and small in scale.
Big Pit	Torfaen	1880–1980	Coal, Iron	(well documented example) The main shaft was deepened in 1878 to reach the Old Coal seam at 293 feet.
Billingsley Colliery	Shropshire	1794–September 1921	Coal, Ironstone	(well documented example) Wyre Forest Coal Measures worked from outcrop down to about 900 ft, with ironstone in the same ground — shallow, small-scale coal that never sustained a company for long.
Bilston Glen Colliery	Midlothian	Sunk from 1952; production from 1963–1989	Coal	(well documented example) Bilston Glen worked deep Limestone Coal Formation seams in the centre of the Midlothian basin.
Binnend Oil Works	Fife	1878–1894 (mines)	Oil Shale	(well documented example) The mines followed a single oil shale bed — the northern end of a seam running some 22 miles to Cobbinshaw — down its dip at 10 to 27 degrees, the bed's inclination dictating that the workings were inclines rather than shafts and that their far ends lay below sea level.
Birchenwood Colliery	Staffordshire	About 1891–Pits about 1932; coke works July 1973	Coal	(well documented example) The colliery worked the gassy Coal Measures of the North Staffordshire coalfield at Kidsgrove, on the same seams as the Talke pits nearby.
Birdshill Quarry	Carmarthenshire	Worked by the early 19th century–No reliable closure date has yet been located.	Limestone	(surviving physical example) A quarry whose worth now is the bedded Ordovician limestone section it left exposed, and the fauna preserved through it, as this record's geology describes.
Birley Collieries	South Yorkshire	Birley West from the 1870s–1943	Coal	(well documented example) The collieries worked the Silkstone and Parkgate seams of the South Yorkshire Coal Measures, an exploring heading in 1876 being driven ninety yards past a fault to prove the coal beyond it.
Bishop Middleham Colliery	County Durham	1846–1936	Coal	(historical documentary reference) Worked named Coal Measures seams — Five Quarter, Main Coal, Busty and Harvey — beneath the Permian magnesian limestone on the concealed eastern edge of the Durham coalfield.
Black Park Colliery	Wrexham	Early 19th century–1949 (shaft to 1968)	Coal	(well documented example) Worked the Main, Two Yard, Yard and Half and Trevor seams at the southern end of the Denbighshire coalfield.
Black Vein Colliery	Caerphilly	Shafts sunk 1840; at work by 1842–1921	Coal	(well documented example) The colliery worked the Black Vein, a bedded seam averaging ten feet and reaching fourteen, whose gassiness defined the character of every pit that took it.
Blackhall Colliery	County Durham	Sunk from 1909; coal drawing began 1914–16 April 1981	Coal	(well documented example) This record names specific worked seams — Main, Low Main, Hutton, Five Quarter, Harvey and Yard — a direct match for this geology record's coal-seam example.
Blackrod Colliery	Greater Manchester	1855–1930	Coal	(historical documentary reference) Middle Coal Measures of the Lancashire coalfield in the Wigan district; no seam list specific to the Blackrod pits was found, and the link rests on the coalfield and the seams named for the company's later holding at Ellerbeck.
Blaenclydach Colliery	Rhondda Cynon Taf	Levels from the early 1860s–No reliable closure date has yet been located.	Coal	(well documented example) The colliery worked the No. 3 Rhondda and Pentre seams at the head of the Clydach valley.
Blaengwawr Colliery	Rhondda Cynon Taf	1843–1926	Coal	(well documented example) The colliery worked three named bedded seams of the Aberdare steam-coal sequence — the four-feet, six-feet and nine-feet veins — with a pit to each.
Blaenhirwaun Colliery	Carmarthenshire	Shafts sunk at the end of the 19th century–1 September 1962	Anthracite	(well documented example) The colliery worked the Green, Trichwart, Big Vein, Stanllyd, Pumpquart and Gras anthracite seams near the western extremity of the South Wales coalfield.
Blantyreferme Colliery	South Lanarkshire	Sinking 1894–No reliable closure date has yet been located.	Coal	(well documented example) The record names the Ell, Main, Upper and Virgin coals of the Lanarkshire coalfield worked in turn from the 1890s.
Bogside Colliery	Fife	opened 1957-59 (sources differ on the exact year)–1985-86 (sources differ on the exact year)	Coal	(well documented example) Worked the Upper Hirst Coal Measures seam, connected underground to the neighbouring Castlehill and Solsgirth drift mines.
Boldon Colliery	Tyne and Wear	1869–24 June 1982	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the Durham coalfield, sinking towards the Hutton Seam; the full sequence worked is not named in any source located.
Bonville's Court Colliery	Pembrokeshire	1842 or 1855 (sources differ)–1930	Anthracite	(well documented example) The record turns on the Lower Level and Kilgetty veins worked between the Harbour and Erroxhill faults, and on the disturbance of the Pembrokeshire anthracite seams.
Boosbeck Mine	North Yorkshire	1872 (shafts sunk); in the Lists of Mines from 1873–1887 (the Durham Mining Museum gives 1886)	Ironstone	(well documented example) The Cleveland ironstone worked here is a bedded sedimentary ore, taken from a seam at around 288 feet in the Lias, with a thick water-bearing running sand above it.
Boothen Colliery	Staffordshire	By the 1860s–No reliable closure date has yet been located	Coal, Ironstone	(well documented example) Coal seams (Little, Cannel Row, Great Row, Spencroft) alternating with the Bassey Mine and Gubbin ironstones of the Potteries Middle Coal Measures.
Boulby Alum Quarries	North Yorkshire	1650s–1871	Alum	(well documented example) A bedded Jurassic alum shale up to 60 m thick in the sea cliffs — quarried, not mined, because the alum had to be manufactured out of it rather than extracted from it.
Bowhill Colliery	Fife	1895 (coal); earlier ironstone working–May 1965	Coal, Iron	(well documented example) Worked named Coal Measures seams from the Bower Bank (81 fathoms) to the Two Feet/Dunfermline Splint (219 fathoms).
Box Quarry	Wiltshire	Worked from at least the 17th-18th century–1968	Freestone	(well documented example) The mine's own recorded geology explicitly describes working a bedded Jurassic Great Oolite limestone.
Brackley Colliery	Greater Manchester	1878–1879 (sources differ)–1964	Coal	(well documented example) The record sets out the full Lancashire Coal Measures sequence at the No. 1 shaft by depth, from the Cannel Mine at 254 feet to the Arley at 874, and turns on the Smith seam being only 22 inches thick.
Braysdown Colliery	Somerset	1845–29 October 1959	Coal	(well documented example) Thin bedded coals of good grade, folded and faulted by the Variscan earth movements — the reason a Somerset shaft had to be sunk 1,834 ft for a comparatively small output.
Brereton Colliery	Staffordshire	By at least 1814–July 1960	Coal, Fireclay, Ironstone	(well documented example) Coal Measures seams of the Cannock Chase coalfield at its northern corner, worked as the Shallow, Yard and Deep, lying around 1,600 feet near Rugeley and separated from the shallower South Staffordshire field by the Bentley Fault, with ironstone and fireclay in the same measures.
Bridgeness Colliery	Falkirk	By 1770 (Grange colliery); North Engine Pit 1777–No reliable closure date has yet been located.	Coal, Ironstone	(well documented example) The record names the Main, Red, Smithy, Six Feet and Navigation coals worked in turn, and turns on the Smithy Coal being sunk for in 1777 as a seam to mix with the Main Coal for the London market.
British Rhondda Colliery	Neath Port Talbot	1890–1935	Coal	(historical documentary reference) The Four Feet, Lower Four Feet, Six Feet and Nine Feet seams are named in the Lists of Mines.
Brookall Ditches Colliery	Gloucestershire	By 1840–After 1880	Coal	(well documented example) The Parkend Delph, one of six veins the Park End group was working in 1840 with nearly five million tons reckoned unworked — the deepest and best-capitalised coal in the Forest at that date.
Brora Colliery	Highland	Coal recorded at Brora from 1529; first shaft sunk 1598–1974	Coal	(well documented example) A bedded coal seam like any other in its mining behaviour — outcrop bell pits first, then a shaft to follow it down dip past a fault — but Jurassic rather than Carboniferous in age, which makes Brora the exception among British coalfields.
Broughton Colliery	Wrexham	Old colliery sunk 1835; New Broughton 1883–New Broughton 1910; Broughton Hall 1978	Coal	(well documented example) The colliery worked the Denbighshire coalfield around Broughton, west of Wrexham, in ground wet enough to need a new pumping engine in 1869.
Brown End Quarry	Staffordshire	Mid 18th century–1960s	Limestone	(well documented example) The quarry exposes bedded Carboniferous limestone — the Milldale limestone, formed from the remains of sea creatures accumulating in still water some 300 metres deep in the North Staffordshire Basin — and it is that section which the SSSI protects.
Broxtowe Colliery	Nottinghamshire	Shafts sunk 1863–65; colliery returned from 1894–1929; shafts filled 1946	Coal	(historical documentary reference) The Top Hard, Deep Soft and Deep Hard seams are named in the Lists and the abandonment summary.
Brunton Bank Quarry	Northumberland	No reliable opening date has yet been located.–Disused by 1969, when the site was notified	Limestone, Sandstone	(surviving physical example) A quarry whose whole scientific value is its bedding: the Main Posts of the Great Limestone, a 0.2 m shale parting at their base, and the metre-thick Chaetetes Band beneath, exposed in section as this record describes.
Brymbo Colliery	Wrexham	By 1792 (surface digging from the 15th century)–1938	Coal, Ironstone	(well documented example) Denbighshire Coal Measures with ironstone in the same ground — the reason one estate could raise both the ore and the fuel for its own furnaces.
Brynhenllys Colliery	Powys	1872–1955	Anthracite	(well documented example) The record turns on the anthracite of the northern outcrop of the South Wales coalfield, the colliery's coal being judged fully up to the standard of the Stanllyd or Peacock seam.
Brynkinalt Colliery	Wrexham	1860s–November 1968 (coal from 1928)	Coal	(well documented example) Worked the Five Feet, Six Feet, Red Coal, Seven Feet, Diamond and Three Yard seams at the southern tip of the Denbighshire coalfield, where the measures continue under the English border.
Buckhill Colliery	Cumbria	1873–27 November 1932	Coal, Fireclay, Ironstone	(historical documentary reference) Cumberland Coal Measures: Main Band, Little Main, Lickbank, Three Quarters and Yard seams, with fireclay and ironstone, in the museum's abandonment record.
Bullcliffe Wood Colliery	West Yorkshire	Sinking started 1927–30 August 1985	Coal	(well documented example) The Barnsley seam and, by 1954, the Top Haigh Moor, both Middle Coal Measures coals lying close enough to the surface on the western side of the Yorkshire coalfield to be won by drifts driven in from the outcrop rather than by sinking.
Bullcroft Colliery	South Yorkshire	1911–25 September 1970	Coal	(well documented example) Sunk to the Barnsley seam at around 660 yards and deepened to the Dunsil at 682 yards, the difficulty lying wholly in the water-bearing cover above the coal rather than in the seams themselves.
Bullhouse Colliery	South Yorkshire	No reliable opening date has been located–Sources differ: 1915 or 1918 for workings; still returned in 1954	Coal, Fireclay	(well documented example) The Halifax Hard Bed of the Lower Coal Measures at the western edge of the Yorkshire coalfield, worked with the fireclay of the same measures; the iron in those strata is what makes the abandoned workings discharge ochre.
Bunker's Hill Colliery	Staffordshire	Sunk 1853–No reliable closure date has yet been located.	Coal	(well documented example) The pit worked the gassy Banbury, Bullhurst and Ten Foot coals of the North Staffordshire Coal Measures, where firedamp came off the floor fast enough to fill a heading between the fireman's test and his shot.
Burghlee Colliery	Midlothian	c. 1860–1964 (abandoned 1965)	Coal, Fireclay, Ironstone	(well documented example) Burghlee worked the Midlothian coalfield's bedded measures, taking ironstone and fireclay from the same sequence as the coal.
Burngrange Oil Shale Mine	Midlothian	1936–1962	Oil Shale	(well documented example) Worked the oil-bearing shale beds of the Lothian (cannel) shales.
Bursledon Brickworks	Hampshire	1897–1974	Brick Clay	(well documented example) Worked the London Clay of the Hampshire Basin, a bedded deposit with oxidised brown clay above blue.
Burtersett Flag Stone Mine	North Yorkshire	In the returns from 1882–Still returning sandstone in 1929	Flagstone, Sandstone	(well documented example) The workable stone is a Yoredale sandstone bed lying between limestones in the rhythmic Carboniferous sequence, which is why it was followed in from the hillside as a bed rather than quarried from above.
Butsfield Quarry	County Durham	No opening date has been located–Returned in 1922; no closure date located	Ganister	(well documented example) Ganister occurs as a bedded seatearth beneath Coal Measures coal seams, which is how it was worked in this district.
Cae Coch Sulphur Mine	Conwy	1607–1942	Pyrite	(well documented example) The pyrites forms a single stratabound bed up to 2.2 m thick and about 200 m along strike, sandwiched between the Dolgarrog Volcanic Formation below and the Llanrhychwyn Mudstones above, and thickest in the axial zones of folds. The most recent genetic model has it pyritised in place within anoxic sea-floor muds, which is why it is bedded rather than veined.
Caerbryn Colliery	Carmarthenshire	c. 1850s–1930s	Anthracite	(well documented example) Four locally named anthracite seams, equated on the abandonment plans with the Four Feet to Bute seams of the South Wales sequence.
Calcutts Colliery	Shropshire	c. 1588–c. 1900	Coal, Brick Clay	(well documented example) Lower Coal Measures outcropping on the slope above the Severn, with coal, ironstone and clay in the same shallow ground — few, thin and shallow seams that were worked out early and left clay as the only thing worth getting.
Califat Coal Mine	Leicestershire	Leased 1852, sunk 1854–Early 1870s	Coal	(historical documentary reference) A Leicestershire coalfield pit working Coal Measures seams in near-horizontal beds — and undone, in 1863, by water standing in a neighbour's abandoned workings in the same sequence.
Camerton Colliery	Somerset	1781–1950	Coal	(well documented example) Thin Coal Measures seams tightly folded and faulted by the Variscan movements — along the Radstock Slide Fault the broken ends of one seam can be 1,500 ft apart — which is why a Somerset shaft went 1,818 ft for coal a Midlands pit reached in a few hundred.
Canonbie Colliery	Dumfries and Galloway	1854–1922	Coal	(well documented example) Six thick bituminous coal seams within about 230 feet of strata in the Pennine Middle Coal Measures, dipping south beneath a New Red Sandstone cover into the Solway syncline; the field is largely concealed, which is why it had to be proved by survey and borehole.
Caprington Colliery	East Ayrshire	By 1781–No reliable closure date has yet been located.	Coal	(well documented example) The record turns on two seams worked one above the other — the Ell coal at three feet six inches and the Blind coal three feet thick fifteen fathoms below — and on the Ell coal's own roof forming part of a surface cover only eighteen feet thick.
Carberry Colliery	East Lothian	Sunk from 1866–1960	Coal	(well documented example) Coal Measures seams of the East Lothian coalfield on the eastern limb of the Midlothian basin — the Five Feet, Four Feet, Great Seam and Jewel — worked for house, gas and steam coal.
Carmyllie Quarries	Angus	Late 18th century–20th century (railway closed 1965)	Freestone	(well documented example) Flaggy Old Red Sandstone splitting along its bedding into flat sheets — fissility from bedding, not from cleavage, which is what separates a pavement quarry from a slate quarry.
Carronhall Colliery	Falkirk	Leased by Carron Company 1760; William Pit 1860s–Nationalised with the Carron Company's last collieries	Coal, Fireclay	(well documented example) The colliery worked the Crow, Main and Upper and Lower Coxrod seams of the Stirlingshire coalfield, coal noted as particularly suitable for the blast furnaces.
Carway Colliery	Carmarthenshire	1863–July 1960	Anthracite	(well documented example) The colliery worked the Big Vein, Braslyd, Ddugaled, Felin and Soap anthracite seams on the western outcrop of the South Wales coalfield.
Castlebridge Colliery	Clackmannanshire	Sinking from 1978; production from 1984–2002	Coal	(well documented example) The complex worked the Upper Hirst coal as a single bedded seam across a wide area, which is why five separate accesses were joined into one underground system rather than sinking a pit to each district.
Catherton Colliery	Shropshire	Late 18th century–c. 1889	Coal	(well documented example) A single significant seam beneath the dolerite cap of Clee Hill, outcropping on the southern and eastern slopes — worked from the outcrop inwards and downwards for seven centuries, and reachable in quantity only once shafts could be sunk through the cap.
Cawdor Quarry	Derbyshire	1857–No reliable closure date has yet been located.	Limestone	(well documented example) The record describes hard limestone of the Eyam Limestone Formation, a bedded Carboniferous unit about 330 million years old, quarried from an open face that is now an SSSI.
Cefn Coed Colliery	Neath Port Talbot	Sinking begun 1921; completed 1928–20 April 1968	Coal	(well documented example) Anthracite seams at the western end of the South Wales coalfield, buried under hard Pennant sandstone that took seven years and four attempts to sink through.
Chaloner Ironstone Mine	North Yorkshire	1853 (local timeline) or October 1869 (Lists of Mines)–12 August 1939	Ironstone	(historical documentary reference) The Cleveland Main Seam of the Cleveland Ironstone Formation, worked as part of the Eston group.
Charlestown Limeworks	Fife	1756–1956	Limestone	(well documented example) The works burnt bedded Carboniferous limestone quarried from the Earl of Elgin's ground immediately behind the kilns, the kiln range being built into the slope so the bedded stone could be fed in from above and the lime drawn out below.
Cherry Hinton Pit	Cambridgeshire	By the 13th century, possibly Roman–Early 1980s	Chalk	(well documented example) The record describes a section through bedded Cretaceous Chalk — the Zig Zag Chalk Formation, the Plenus Marls, the Melbourn Rock and the Holywell Nodular Chalk above — with the building stone won selectively from the harder beds within it.
Chilmark Quarries	Wiltshire	Worked from medieval times, reputedly from Roman times–Quarrying ceased c.2007; reopened 2019	Limestone	(well documented example) A Jurassic Portland-beds limestone, evenly bedded and structurally stable enough that its underground galleries needed unusually few support pillars — the same quality that later suited it to storing munitions.
Chilton Colliery	County Durham	1872–1966	Coal	(well documented example) Its geology field records the colliery working the Coal Measures of the south Durham coalfield between Ferryhill and Bishop Auckland — bedded coal seams.
Chislehurst Caves	Kent	at least the 13th century–1830s-40s	Chalk, Flint	(well documented example) The workings follow the Upper Chalk, a soft bedded sediment strong enough to stand in pillared galleries without timbering — which is why the system reaches 22 miles.
Chislet Colliery	Kent	Sinking from May 1914; coal reached 1919–1969	Coal	(well documented example) Chislet worked Coal Measures seams concealed beneath thick chalk, the defining problem of the Kent coalfield.
Chopwell Colliery	Tyne and Wear	Boring from 1781; Maria and Conclusion Pits sunk 1795-99–25 November 1966	Coal	(well documented example) This record names specific worked seams — Brockwell, Five Quarter, Stone Coal, Three Quarter, Towneley, Hutton and Tilley — a direct match for this geology record's coal-seam example.
Cilely Colliery	Rhondda Cynon Taf	1872–1950	Coal	(well documented example) The record names the Five Feet seam at 404 yards and the Abergorki at 156 yards worked from two shafts of different depths.
Clashach Quarry	Moray	from Early 1800s	Freestone	(well documented example) Bedded New Red Sandstone whose large-scale cross-bedding records the dunes it was laid down as — the bedding is both the geology and the reason the stone cuts as it does.
Clyde Colliery, Hamilton	South Lanarkshire	1890–1930	Coal, Ironstone	(historical documentary reference) Five named Lanarkshire coals and the Blackband ironstone appear in the Lists of Mines.
Cocking Quarry	West Sussex	By 1715–1999	Chalk	(well documented example) The record describes chalk quarried from the bedded Cretaceous Chalk of the South Downs, burnt for lime in kilns beside the lower pit and latterly ground for sale as powdered chalk.
Coegnant Colliery	Bridgend	1882–1981	Coal, Ironstone	(well documented example) The colliery worked a stacked series of named bedded coal seams in the South Wales Coal Measures — Six Feet, Seven Feet, Two Feet Nine, Upper Nine Feet, Bute and Yard — moving between them as each was exhausted.
Collins Green Colliery	Merseyside	Shafts from an early date; sinking from 1873–1931	Coal	(well documented example) Collins Green worked the bedded seams of the St Helens coalfield, its deep shafts reaching the Lower Florida seam at 516 m.
Combs Colliery	West Yorkshire	Sunk by Joshua Ingham–No reliable closure date has yet been located.	Coal	(well documented example) The colliery worked the New Hards, Wheatley and Blocking Bed seams of the West Yorkshire Coal Measures south of the Calder.
Coombefield Quarry	Dorset	1890s–working life ended by 2006	Freestone	(well documented example) The mine's own recorded geology explicitly describes the Jurassic oolitic limestone beds of the Portland Freestone.
Corncockle Quarry	Dumfries and Galloway	Early 19th century–Still active	Sandstone	(well documented example) The quarry works a single named sedimentary unit, the Corncockle Sandstone Formation, and it is the bedding planes within it — split apart in the course of quarrying — that carry the fossil trackways.
Cornelly Quarries	Bridgend	from Industrial-scale working from the Industrial Revolution	Limestone	(well documented example) Bedded Carboniferous limestone whose unusual purity — better than 97 per cent — is the whole reason it is worth quarrying for flux rather than merely for roadstone.
Cornsay Colliery	County Durham	1868–September 1953	Coal, Fireclay	(well documented example) Thin Durham seams outcropping on the valley sides and taken by drift, with the fireclay seatearth beneath them worth more by the end than the coal above.
Cortonwood Colliery	South Yorkshire	1873–25 October 1985	Coal	(well documented example) Cortonwood worked a stacked sequence of Coal Measures seams, reached in turn by deepening the same two shafts.
Cossall Colliery	Nottinghamshire	1870–November 1966	Coal	(well documented example) A Kilburn-seam colliery, working one of the deeper coals of the Nottinghamshire and Derbyshire field along with the Furnace Coal and Tupton.
Cragg End Flag Stone Mine	North Yorkshire	Listed in 1888–No reliable closure date has yet been located.	Flagstone	(historical documentary reference) Flagstone is got from sandstone beds within the Carboniferous Yoredale sequence, worked for the way a bed splits along its bedding planes — the bedded deposit type in its most literal form.
Craghead Colliery	County Durham	1839–11 April 1969	Coal, Fireclay	(well documented example) The returns list the bedded Durham Coal Measures seams worked against each shaft — Five Quarter and Main Coal in the upper pits, Hutton, Low Main and Maudlin in the lower — within the 487 feet the 1878 Oswald log records.
Craigend Colliery, Maddiston	Falkirk	1854–November 1935	Coal, Ironstone	(historical documentary reference) Stirlingshire Coal Measures: Coxrod, Main, Mill, Glenfuir, Splint, Auchengane and Ball seams with blackband ironstone, from the museum's Lists of Mines entries.
Cribbwr Fawr Colliery	Bridgend	Working by 1884; the Rock Fawr seam from about 1885–About 1935	Coal	(well documented example) The colliery worked the Upper and Lower Nine Feet, 20-inch, Fawr, Siatot, Five Quarter and Cribwr Fawr seams on the southern rim of the South Wales coalfield, its workings bounded to the north by the Newlands Thrust.
Crigglestone Colliery	West Yorkshire	Sinking began 1889–No reliable closure date has yet been located.	Coal	(well documented example) The record names the Lidgett and the Low and Top Haigh Moor seams of the Yorkshire Coal Measures, the Haigh Moor being one of the West Riding's principal coking coals.
Cross Knave Colliery	Gloucestershire	By 1835–After 1910	Coal	(well documented example) The Coleford High Delf, the bedded seam of the western Forest of Dean, within thirty yards of the surface here and workable by three men with a horse whim.
Crynant Colliery	Neath Port Talbot	1880–3 March 1956	Coal, Anthracite	(well documented example) The record turns on the anthracite of the Dulais valley on the northern outcrop of the South Wales coalfield, worked by levels driven into the valley side.
Crûg Farm Quarry	Carmarthenshire	No reliable opening date has yet been located.–Disused by 1980, when the site was notified	Limestone	(surviving physical example) A quarry valued for the bedded Upper Ordovician shelly limestone it exposes and the fauna preserved through it, as this record's geology describes.
Cwm Cynon Colliery	Rhondda Cynon Taf	Sinking began 1889–1949	Coal	(well documented example) The colliery worked the Two Feet Nine, Six Feet and Nine Feet steam coal seams of the Cynon valley, reached by shafts 508 yards deep.
Cwmaman Colliery	Rhondda Cynon Taf	Sunk 1849; coal found December 1849–1935	Coal, Ironstone	(well documented example) The colliery worked the steam coal seams of the Aberdare district — the Four-Feet, Two-Feet-Nine, Gellideg, Nine Feet, Bute, Yard, Red and Seven Feet — with ironstone raised alongside the coal.
Cwmbran Colliery	Torfaen	A colliery shown here in 1811; levels driven late 1830s–1927	Coal, Fireclay	(well documented example) The colliery worked the Black Vein, Meadow Vein, Elled, Red Ash and Old Coal seams of the Gwent coal basin, reached by an adit driven 2,080 yards through the Old Red Sandstone, Main Limestone and Millstone Grit.
Cwmgorse Colliery	Neath Port Talbot	Returned from 1894–1964 or 1965	Anthracite	(well documented example) The colliery worked anthracite at Gwaun-cae-Gurwen in the Amman valley, at the north-western edge of the South Wales coalfield.
Cwmgwrach Colliery	Neath Port Talbot	Early 1800s; Empire colliery 1898–c. 1960	Coal, Anthracite	(well documented example) The record names the Six Feet, Nine Feet, Upper Four Feet and Bluers seams of the Vale of Neath anthracite worked from levels and drifts on the hillside.
Cynwyd Forest Quarry	Denbighshire	No reliable opening date has yet been located.–Disused by 1983, when the site was notified	Slate, Mudstone	(surviving physical example) A quarry whose worth is the bedded Ordovician siltstone and mudstone section it left exposed, and the shelly fauna preserved through those beds, as this record's geology describes.
Dalmellington Iron Works	East Ayrshire	1847–1921	Iron, Coal	(well documented example) The works drew blackband ironstone, coal and limestone together from the Carboniferous sequence of the Doon Valley, the combination that made a Waterside ironworks worth building.
Dark Hill Colliery	Gloucestershire	By 1813–c. 1914	Coal	(well documented example) The Coleford High Delf, a six-foot bedded seam at the base of the Pennant Group, worked here by level from its outcrop as it was across the western Forest of Dean.
Darnley Lime Works	Glasgow	By 1610–c. 1959	Limestone, Fireclay	(historical documentary reference) The record describes limestone, fireclay and coal taken together from the Carboniferous sequence of the Clyde basin; no individual bed is named in any source located.
Deep Navigation Colliery	Merthyr Tydfil	Sinking from October 1873–29 March 1991	Coal	(well documented example) This record names specific worked seams — the Nine Feet, Seven Feet and Yard seams — a direct match for this geology record's coal-seam example.
Digby Colliery	Nottinghamshire	1866–Between 1934 and 1939	Coal	(well documented example) Worked the Deep Hard, Deep Soft and Tupton seams of the Middle Coal Measures, giving up the older seams one by one until only the Tupton was left.
Diglake Colliery	Staffordshire	1870 (earlier pit 1733 to c. 1850)–June 1905	Coal	(well documented example) Seven named seams from the Ten Feet down to the Five Feet in the Middle Coal Measures; the Ten Feet's nearness to the flooded old workings caused the 1895 inrush.
Dog Delf Colliery	Gloucestershire	1872–1899 (gale forfeited)	Coal	(well documented example) The Dog Delf vein — ninety-four acres of thin, irregular bedded coal in the gaveller’s own description, which is why nobody who took it made anything out of it.
Donibristle Colliery	Fife	No reliable opening date has been located–No reliable closure date has been located	Coal	(well documented example) Faulted Coal Measures seams of the southern Fife coalfield, including the Mynheer coal, rising generally to the south and cropping out within the leased ground, overlain across most of the workings by the peat moss of Mossmorran.
Donisthorpe Colliery	Leicestershire	1871–12 April 1990	Coal	(well documented example) A bedded succession worked downwards — the Little Coal, the Main Coal and, after the 1890 deepening, the Stockings — with the Woodfield seam giving its name to one of the districts opened in the 1940s.
Double Arches Pit	Bedfordshire	1916–1985	Silica Sand	(well documented example) Notified as an SSSI in 1988 for being the best accessible exposure of the Lower Greensand and Gault junction in the Leighton Buzzard area, with a unique example of channelling in the junction beds and a clear development of the Cirripede bed.
Douglas Castle Colliery	South Lanarkshire	by the 1910s–1950s (precise date unrecorded)	Coal	(well documented example) Worked the named Coal Measures seams (Nine Feet, Seven Feet, Dunglass, Four Feet, Humph) recorded at the colliery.
Dowlow Works	Derbyshire	1899–Still active	Limestone	(well documented example) A bulk quarry in massive Carboniferous limestone beds, worked for the consistency and purity of the bedded rock itself rather than for anything concentrated within it.
Dry Rigg Quarry	North Yorkshire	1938 (present workings); Combs Quarry from the 18th century–Still active	Sandstone	(well documented example) Dry Rigg works the Horton Formation, a Silurian greywacke laid down as a graded sedimentary sequence, quarried as bedded rock rather than from a vein or seam.
Dudley Colliery	Tyne and Wear	Sinking from 19 April 1854; coal from 1856–1977	Coal	(well documented example) The record lists the bedded Northumberland Coal Measures seams the colliery worked in turn — Yard first, then Main Coal, Low Main, Bensham, High Main, Beaumont, Top Five Quarter, Top Busty, Harvey and Maudlin — within the 728 feet of strata the 1854 sinking log records.
Duke Wood Colliery	West Yorkshire	c. 1862–1863–No reliable closure date has yet been located.	Coal	(well documented example) The record turns on Coal Measures seams lying shallow enough at Clayton West to have been worked by bell pits from the surface, whose hollows still show in the woodland, long before the shaft colliery was sunk.
Dulcote Quarry	Somerset	Mid-19th century; serious working from c. 1890–Worked out; redeveloped from 2016	Limestone	(well documented example) The quarry worked bedded Carboniferous Limestone, overlain here by Triassic mudstones and sandstones, as an open face rather than following any vein.
Dunkerton Colliery	Somerset	1904–1925 or 1933 (sources differ)	Coal	(well documented example) The record names the Great, Bull, Slyving, Top Little and Under Little veins and the Farrington series worked in turn, and turns on the Great Vein being only two feet six inches thick.
Dunnikier Colliery	Fife	Panny No. 1 sinking about 1880; Lena sunk 1873–1927	Coal	(well documented example) The colliery worked the Black, Glassee, Parrot, Rough, Five Feet and St Clair seams of the Fife coalfield, the Parrot being the cannel coal behind its gas-coal returns.
Durie Colliery	Fife	1855–After 1903	Coal	(historical documentary reference) Fife Coal Measures at Leven; ochre beds were worked alongside the coal in Sillerhole Den.
Eaglesbush Colliery	Neath Port Talbot	By 1802; a new pit sunk on the estate by 1845–No reliable closure date has yet been located.	Coal	(well documented example) The 1845 lease names the bedded seams under the Eaglesbush estate — the Two Foot vein, the Rotten or New vein and the Eskyn vein — and the 1842 Commission gives the worked seam as four feet six inches thick at 42 fathoms.
Earlseat Colliery	Fife	Mines Nos. 1-5 opened May 1903; NCB drift 1950–Mines closed September 1927; drift December 1958	Coal	(well documented example) The Dysart Main and Lower Dysart worked at Earlseat are beds in the Fife coal measures.
Earnock Colliery	South Lanarkshire	Working by 1881; returned to the Inspectors from 1894–Still shown on the 1936 Ordnance Survey; demolished since	Coal	(well documented example) The Blackband, Ell, Humph, Kiltongue, Main, Pyotshaw and Splint seams worked at Earnock are beds in the Scottish Coal Measures of the Lanarkshire coalfield.
Easington Colliery	County Durham	sinking begun 1899; first coal 1910–1993	Coal	(well documented example) The mine's own recorded geology explicitly describes Carboniferous coal seams of the Durham Coalfield.
East Benhar Colliery	West Lothian	c. 1938–September 1957	Coal	(well documented example) Bedded Coal Measures seams: the Virtuewell, six feet thick here, and the thinner Ladygrange.
East Gawber Colliery	South Yorkshire	1856–1921, or before 1922	Coal	(well documented example) East Gawber worked coal seams of the South Yorkshire coalfield north of Barnsley; the sources read name none of them individually.
Eastern Quarry	Kent	By 1940–1990	Chalk	(well documented example) Works the bedded Upper Chalk of the North Kent up-fold, where the thickness available inland from the river reaches some 50 m beneath a cover of river terrace gravels, head deposits and, in places, Palaeocene sands and London Clay.
Eastern United Colliery	Forest of Dean	1910–30 January 1959	Coal	(well documented example) The gale held six coal seams, the Coleford High Delf chief among them at a reputed five feet, but monoclinal folding of the beds lost them in the main headings and forced long cross dipples to pick them up again — bedded geology dictating the whole layout of the mine.
Easthouses Pit	Midlothian	Extension Pit opened 1909–1980s	Coal	(well documented example) Easthouses worked the bedded measures of the Midlothian coalfield, the 1909 Extension driven as a drift following the coal laterally rather than sunk deeper.
Eccleston Quarry	Lancashire	No reliable opening date has yet been located.–Abandoned and flooded after the Second World War	Sandstone	(historical documentary reference) A quarry worked for a flaggy, well-bedded sandstone that split thin enough to roof buildings — the bedding is what made the stone useful, as this record's geology notes.
Eckington Mine	Derbyshire	1993–January 2019	Coal	(well documented example) The record names the bedded Eckington Deep Soft (Flockton) seam worked by the drifts, and places it above the historic Parkgate and Thorncliffe seam workings 65 and 80 metres below.
Eden Colliery	County Durham	1844–18 July 1980	Coal, Fireclay	(historical documentary reference) Ten named Durham Coal Measures seams appear in the Lists of Mines; Whellan describes the Hutton at 30 feet with a stone band.
Elba Colliery	Swansea	Drift developed 1881; reopened by 1896–Abandoned 1905; successor drift closed soon after 1911	Coal	(well documented example) The Swansea Three Foot and Six Foot and the Penscallen worked at Elba are beds in the western part of the South Wales coalfield.
Eldin Colliery	Midlothian	By 1874–No reliable closure date has yet been located.	Coal, Fireclay	(well documented example) The record turns on Midlothian Coal Measures seams interleaved with fireclays worked together, the fireclay fired into bricks on the colliery's own site.
Ellistown Colliery	Leicestershire	1874–1991	Coal, Fireclay, Ironstone	(well documented example) Concealed Coal Measures beneath the New Red Sandstone, dipping about 1 in 14 with no faulting — the Lower Main nine feet thick at 329 yards, and four fireclay and four ironstone seams passed on the way down.
Elphingstone Colliery	East Lothian	Working by 1842; sinking date not established–Last return 1920; closure date not established	Coal	(well documented example) The Five Feet, Four Feet, Great Seam, Splint and Three Feet worked at Elphingstone are beds in the East Lothian coal measures.
Elsecar Colliery	South Yorkshire	1794–1923 (Newcomen engine); pits later	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the South Yorkshire coalfield; the individual seams worked are not named in any source located, so the link is at coalfield level rather than to a named seam.
Emmer Green (Hanover) Chalk Mine	Berkshire	No reliable opening date has yet been located.–No reliable closure date has yet been located.	Chalk, Flint	(well documented example) The mine works the Seaford Chalk Member — white, soft and nodular chalk with abundant flint seams — beneath the sandy clays of the Lambeth Group.
Eston Ironstone Mines	North Yorkshire	Trial quarrying from August 1850; Upsall pit opened 1851–September 1949	Iron	(well documented example) The Cleveland Main seam is a bedded Jurassic marine ironstone that outcrops along the escarpment and dips gently inland — the reason Eston could be entered on the level and worked by pillar and stall over an enormous area.
Exhall Colliery	Warwickshire	Working by 1894; earlier date not established–Still returning 130 people in 1947; closure date not established	Coal	(well documented example) The Ell, Rider, Slate and Two Yard seams worked at Exhall are beds in the Warwickshire coal measures.
Fallahill Colliery	West Lothian	1890–1905	Coal	(well documented example) The Blackband, Furnace, Main and Shotts seams worked at Fallahill are beds in the West Lothian coal measures; the Blackband is the ironstone-bearing coal of the Scottish iron trade.
Far Green Colliery	Staffordshire	By 1859–No reliable closure date has yet been located.	Coal	(historical documentary reference) The record places the pit in the Coal Measures under Hanley and names the seams the Granville concern worked around it — bedded coal seams, the deposit type this record describes; the seam worked at the Big Pit itself is not named.
Farme Colliery	South Lanarkshire	Established in the early 1800s–17 July 1931	Coal	(well documented example) The Ell, Humph, Main, Splint, Upper, Virgin and Kiltongue seams worked at Farme are beds in the Lanarkshire coal measures, following the line of the Clyde.
Fauldhead Colliery	Dumfries and Galloway	1896–1968	Coal, Brick Clay	(historical documentary reference) Scoped honestly to the district: the record establishes that Fauldhead worked the isolated Sanquhar and Kirkconnel basin for household, manufacturing, steam and later industrial coals, with clay raised alongside, but no source read here names a seam.
Fauldhouse Colliery	West Lothian	By 1855–c. 1896 (Dixon's pits); Knowes No. 1 to 1946	Coal, Ironstone	(well documented example) Thin coals (Shotts Ball, Big, Shotts Furnace, Mill, Ball, Main) interleaved with the Slatyband ironstone worked from Nos. 8, 9 and 13.
Felling Colliery	Tyne and Wear	1779–1931	Coal	(well documented example) Felling worked the Durham Coal Measures as a stack of named seams one below another — High Main, Bensham, Low Main, Hutton, Beaumont — each taken in turn as the one above was exhausted.
Fergushill Colliery	North Ayrshire	By 1855–No reliable closure date has yet been located.	Coal	(well documented example) The record names the Ell, Ladyha', Stone, Turf, Wee, Five Quarter-Turf, Linnbed and Parrot coals worked across the numbered pits, different pits on different seams at the same date.
Fernhill Colliery	Rhondda Cynon Taf	Sunk 1869-71–1978	Coal	(well documented example) This record names specific worked seams — Gorllwyn, Four Feet, Two Feet Nine and No.2 Rhondda — a direct match for this geology record's coal-seam example.
Ferrymoor Colliery	South Yorkshire	1915–16–1988 (as Ferrymoor-Riddings-South Kirkby)	Coal	(well documented example) The record turns on the Shafton seam lying only 72 yards down here, shallow enough to be reached by a drift from the surface, where the Barnsley seam at the deep pit next door needed 560 yards of shaft.
Fforchaman Colliery	Rhondda Cynon Taf	Sunk in the 1850s; 1851 and 1856 are both given–25 September 1965	Coal	(well documented example) The Aberdare Four-Feet and the eleven other seams between the Two-Feet-Nine and the Gellideg are beds in the steam-coal measures of the South Wales coalfield.
Ffrwd Colliery	Wrexham	c. 1790s (estate pits); c. 1850 (colliery)–1904	Coal, Fireclay, Ironstone	(well documented example) The record turns on coal, ironstone and fire-clay being worked from the same Denbighshire Coal Measures sequence on one site, feeding the colliery's own blast furnaces and brick kilns as well as the coal trade.
Fishburn Colliery	County Durham	1910–1973	Coal	(well documented example) Its geology field records the colliery working the Coal Measures of south-east Durham beneath the Magnesian Limestone — bedded coal seams, the deposit type this record describes.
Flockton Collieries	West Yorkshire	A pit recorded in 1515–1894	Coal, Ironstone	(well documented example) The pits worked outcropping seams at the transition from the Lower to the Middle Coal Measures, the Flockton Thick and Thin taking their names from this ground.
Fordel Mains Colliery	Midlothian	Returned from 1920; sinking date not established–Last return 1940; closure date not established	Coal	(well documented example) Bryan's Splint, the Five Feet and the Kailblades worked at Fordel Mains are beds in the Limestone Coal Formation of the Midlothian coalfield.
Foredale Quarry	North Yorkshire	1878–No reliable closure date has yet been located.	Limestone	(well documented example) Foredale worked the bedded Great Scar Limestone above the unconformity at the top of the valley side, the gritstone quarries lying below it in the same valley.
Foxes Bridge Colliery	Gloucestershire	1855–10 August 1930	Coal	(well documented example) Five named seams of the Supra-Pennant Group worked in succession down to the Churchway High Delf at 851 ft — bedded coals whose shared drainage across the Forest of Dean syncline is what eventually drowned the pit.
Fremington Edge Quarry	North Yorkshire	Returning by 1905–Still returning in 1950	Chert	(well documented example) Chert occurs here as beds and nodular bands within the Carboniferous limestone of the Yoredale succession — a bedded deposit worked as such, as this record's geology section sets out.
Frodingham Ironstone Mines	Lincolnshire	1859–1981 (underground working)	Iron	(well documented example) A Lower Lias ironstone lens worked first as outcrop quarry and then, where the cover thickened, by room-and-pillar underground — the bed's shape dictating both.
Gannow Colliery	Lancashire	1856–1941	Coal	(historical documentary reference) Burnley coalfield Lower Coal Measures reached by a 229-metre shaft.
Gascoigne Wood Mine	North Yorkshire	1983–2004	Coal	(historical documentary reference) The drift served the concealed Selby coalfield, whose bedded coals were won at five satellite pits and brought here underground; the link is to the field this mine existed to unload rather than to strata worked at this point.
Gate Crag Quarry	Cumbria	Working by 1929–Mining suspended 1929	Slate	(historical documentary reference) A working in the cleaved volcanic tuffs of the Borrowdale Volcanic Group, split along an imposed cleavage rather than the original ash bedding, as this record's geology describes.
Gatewen Colliery	Wrexham	1877–1932	Coal	(well documented example) The colliery worked the Main, Four Feet, Crank, Powell and Smith seams of the Denbighshire coalfield at New Broughton.
Gellyceidrim Colliery	Carmarthenshire	By 1905–1957	Anthracite	(well documented example) The record names the Big, Brynlloi and Peacock seams of the Amman valley anthracite, the Peacock being the coal the district's quality was measured against.
Gentlemen Colliers	Gloucestershire	By 1735–c. 1900	Coal	(well documented example) The Coleford High Delf, the bedded seam underlying the western Forest of Dean, worked here by level from its outcrop as far as gravity drainage would reach.
Gethin Colliery	Merthyr Tydfil	1849–Coal production ceased in the 1920s; pumping until 1947	Coal	(well documented example) The coal measures outcropping at the head of the valleys, alongside ironstone and limestone — the reason Merthyr's ironworks stood where they did, and why they sank their own pits.
Glapwell Colliery	Derbyshire	Sinking begun 11 August 1882–1974	Coal	(well documented example) Coal Measures seams of the concealed Derbyshire coalfield dipping east beneath the Magnesian Limestone: the Top Hard or Barnsley Bed at about 300 yards, with the Deep Hard, Low Main, Blackshale, First Waterloo, Dunsil and Clowne worked at other horizons.
Glenboig Fireclay Mines	North Lanarkshire	1830s; the Glenboig-Inchneuk mine from the 1880s–1956 (Glenboig-Inchneuk); other mines to 1981	Fireclay	(well documented example) Fireclay as seatearth — the leached fossil soil under a coal seam. The leaching that stripped out iron and lime is precisely what made Glenboig's clay worth mining.
Glentaggart Colliery	South Lanarkshire	1943–1969	Coal	(well documented example) The colliery worked the Nine Feet and Seven Feet seams of the Douglas coalfield in upper Lanarkshire.
Glyncorrwg Colliery	Neath Port Talbot	1904 (pits); levels by 1860s–1970	Coal	(well documented example) The record names five bedded seams worked here — the No. 2 Rhondda, Six Feet, Nine Feet, Red Vein and Peacock Anthracite — in the Middle and Lower Coal Measures of the western South Wales coalfield, at semi-anthracite rank.
Goatfoot Colliery	East Ayrshire	1863–1920	Coal	(historical documentary reference) Five named Ayrshire coals appear in the Lists of Mines.
Gospel Oak Colliery	West Midlands	c. 1858–1860–1910	Coal, Ironstone	(historical documentary reference) The Thick, Heathen, Bottom, Thin and New Mine coals and the Whitestone ironstone are named.
Grassmoor Colliery	Derbyshire	1846 (Blackshale from 1861)–August 1950 (winding)	Coal	(well documented example) Worked the whole local sequence of Derbyshire Coal Measures across its numbered pits, from the Top Hard down to the Blackshale the company spent £40,000 to reach.
Great Western Colliery	Rhondda Cynon Taf	August 1851–November 1983	Coal	(well documented example) Worked a long list of named South Wales Coalfield seams — Six Feet, Four Feet, Lower Four Feet, Five Feet, Nine Feet, Red and Fforest Fach — with individual shafts assigned to individual seams as the complex grew.
Great Wyrley Colliery	Staffordshire	Working by 1872 (1806 per museum)–1925	Coal, Ironstone	(historical documentary reference) The Bass, Deep and Shallow coals and ironstone are named in the Lists of Mines.
Greenrigg Colliery	West Lothian	Sunk 1905–1960	Coal, Fireclay, Ironstone	(historical documentary reference) The Lists of Mines name the Main, Mill, Ball and Colinburn coal seams, with fireclay and ironstone returned alongside.
Greenrigg Pit	West Lothian	Sunk 1806–Abandoned by 1856; the row by the 1870s	Coal	(well documented example) Shallow bedded Coal Measures seams worked by a scatter of small pits across Benhar moor.
Greetwell Ironstone Mines	Lincolnshire	c. 1873, certainly by 1879–1939 (ironstone); quarrying to 2003	Ironstone, Limestone	(well documented example) The ore was a near-horizontal bed of Northampton Sand ironstone cropping out along the Lincoln Cliff and on the flanks of Greetwell Hollow, taken first by opencast quarrying and then followed on the level underground through adits driven from the quarry faces.
Gresford Colliery	Wrexham	1908 (sinking); 1911 (production)–1973	Coal	(well documented example) The mine's own recorded geology explicitly describes working the Denbighshire Coalfield's Carboniferous Coal Measures across three named seams.
Gurney Slade Quarry	Somerset	Mid 19th century–Still worked	Limestone	(well documented example) The quarry works Carboniferous limestone on the eastern nose of the Pen Hill Pericline, overlain unconformably by Triassic breccias and marls and a faulted block of Lower Jurassic breccia.
Gwendraeth Colliery	Carmarthenshire	By 1852, possibly earlier–1870s	Coal	(well documented example) The colliery's record names three worked coal seams — the Gras and Dugaled, and the Pumpquart reached at 150 yards when the shaft was deepened — bedded Coal Measures seams of the South Wales Coalfield, worked here at anthracite rank.
Gwersyllt Colliery	Wrexham	Mining from the mid 1840s–1925	Coal	(well documented example) Coal Measures seams at the northern end of the Denbighshire coalfield, worked in changing combinations — the Brassey, Crank, Main, Powell, Two Yard and Queen coals.
Habergham Colliery	Lancashire	1854 (older pits); deep shafts producing by 1870–1941	Coal	(historical documentary reference) The Arley, Blindstone and Top Bed seams of the Burnley Coalfield are named.
Ham Hill Quarries	Somerset	Roman period–Still active	Limestone	(well documented example) The quarries work a single named bed — the Ham Hill Limestone, now placed within the Bridport Sand Formation — laid down in a shallow Jurassic sea, and the quarrymen worked to its bedding and to the vertical fractures cutting it.
Harpur Hill Quarry	Derbyshire	c. 1835–c. 1952	Limestone	(well documented example) The quarry works the bedded Bee Low Limestones of the Derbyshire Carboniferous, burnt on site for quicklime; the chemistry of that bedded stone is also what makes the flooded pit caustic today.
Harraton Colliery	Tyne and Wear	Before 1794–1965	Coal	(well documented example) Its geology field records the colliery working the Coal Measures on the lower Wear, ground mined since the sixteenth century — bedded coal seams.
Harriseahead Colliery	Staffordshire	By 1831–July 1939	Coal	(historical documentary reference) North Staffordshire Coal Measures at the coalfield's north-west rim: Bowling Alley, Holly Lane, Magpie, Banbury, Ragman, Winpenny and Bullhurst seams.
Harry Crofts Colliery	South Yorkshire	Sunk 1924–1926–1930	Coal	(well documented example) Sunk to the Top Hard, a named Coal Measures seam lying in the near-horizontal beds this deposit type describes; the pit's short life is attributed to the state of that ground.
Hartington Colliery	Derbyshire	1855-58 (as New Hollingwood)–1927 (pumping long after)	Coal	(well documented example) Sunk to the Deep Soft or Hollingwood bed at 218 yards, with the Blackshale beneath it proved by a staple shaft in 1879.
Hartley Colliery (Hester Pit)	Northumberland	1845-46–1862	Coal	(well documented example) The mine's own recorded geology explicitly describes working the Northumberland Coalfield's Coal Measures via the Low Main seam.
Haunchwood Colliery	Warwickshire	1855 (recorded working from 1729)–1967	Coal	(well documented example) Bedded Warwickshire steam coals worked down the dip from 1873 on the Gillett system, with only about fifty feet of coal separating these workings from Newdigate’s next door.
Hay Head Quarry	West Midlands	By 1593–Abandoned by 1865	Limestone	(well documented example) The quarries worked the Barr Limestone as a bed at the base of the Wenlock Shale, following its outcrop as a long linear strip along the parish boundary.
Haywood Colliery	Gloucestershire	Gale awarded 1841–1888; plant auctioned 1890	Coal	(well documented example) The colliery worked the Coleford High Delf Seam of the Pennant Group, the principal coal of the Forest of Dean basin.
Hazlerigg Colliery	Tyne and Wear	1892–1964	Coal, Fireclay	(well documented example) The colliery's returns name seven bedded Coal Measures seams — High Main, Main, Yard, Bensham, Beaumont, Low Main (Plessey) and Tilley — and the 1892 shaft log records them as coals within a repeated sandstone, shale and seatearth sequence.
Heaton Colliery	West Yorkshire	Brickworks from 1855 or a little earlier–No reliable closure date has yet been located.	Coal, Fireclay	(well documented example) The pit worked the thin Hard Bed, Soft Bed and Thirty-Six Yard seams of the north Bradford Coal Measures, with fireclay beneath the coal.
Hemsworth Colliery	West Yorkshire	1876–1880 (sinking)–July 1967 (merged into South Kirkby)	Coal	(well documented example) The pit's working life is a sequence of deepenings through the Yorkshire Coal Measures — Shafton at 145 yards, then Haigh Moor in 1897, then the Barnsley seam from 1899 — the stacked-seam pattern this record describes.
Heol Senni Quarry	Powys	Quarried extensively in the 19th century–No reliable closure date has yet been located.	Sandstone	(surviving physical example) A quarry whose section through pebbly, cross-bedded Old Red Sandstone preserves the stacked channels of a Devonian braided river — bedded sediment legible as the environment that laid it down, as this record's geology describes.
Hickleton Main Colliery	South Yorkshire	1892–1994	Coal	(well documented example) Sunk to the Barnsley seam at 492 metres — the thick, productive bed that the Doncaster coalfield was opened up to work, and the same seam pursued at Bullcroft, Brodsworth and Thorne.
Highgate Colliery	South Yorkshire	1916–1985	Coal	(well documented example) The Shafton seam at 45.7 m and the thin Highgate coal at 14.6 m, with a Five Quarter abandonment plan in the national catalogue; the seam's shallow cover made it wet and dictated the working method.
Hill Top Colliery	Lancashire	1948–2014 (first closure 1966; reopened 1997)	Coal	(well documented example) A drift mine on the Union seam of the Lancashire Coal Measures, worked as a bed of consistent thickness — about 4 ft 6 in — with the ironstone nodules through it a constant nuisance to machine cutting, as this record's geology describes.
Hollinswood Colliery	Staffordshire	No reliable opening date has yet been located.–No reliable closure date has yet been located.	Coal	(well documented example) The pit worked the stacked Coal Measures seams of the North Staffordshire coalfield around Talke — the gazetteer names the Birchenwood, Yard, Stony Eight Foot, Rough Seven Foot, Ten Foot and Four Foot in the district's workings.
Holly Bank Colliery	Staffordshire	c. 1850 (as Essington Wood); 1895 (as Holly Bank)–December 1952	Coal, Ironstone	(well documented example) Nine named coal seams of the Cannock Chase coalfield, with ironstone raised alongside; the Eight Feet is described in the accident reports as 5 ft 9 in with a dirt band.
Holmewood Colliery	Derbyshire	1867-68–1968	Coal	(well documented example) First struck a hard coal four feet nine inches thick at 63 yards in 1868 and ended working the Deep Hard, Three Quarter and Tupton seams at 458 yards.
Home Farm Colliery, Hamilton	South Lanarkshire	About 1864 to 1870–1925	Coal	(historical documentary reference) Lanarkshire Coal Measures under the Clyde's sands and gravels: Ell, Main and Splint at 47 to 72 fathoms, with the Drumgray, Kiltongue, Humph and Blackband seams later.
Hook Colliery	Pembrokeshire	1850–1948	Coal	(well documented example) The colliery worked anthracite seams of the small, geologically distinct Pembrokeshire Coalfield close to the Western Cleddau estuary.
Hopewell Colliery	Gloucestershire	from 1822	Coal	(well documented example) The Coleford High Delf is a bedded Carboniferous seam followed by adit rather than shaft — and at 18 inches high it shows how little working room a bedded deposit can offer.
Hopton Wood Quarries and Middleton Mine	Derbyshire	Quarried from at least the 18th century; underground drift begun 1959–Middleton Mine closed 2005; quarrying ceased 2006	Limestone	(well documented example) A Carboniferous limestone pure and even enough to polish like marble — the quality that made it a decorative stone rather than aggregate, and that let 120,000 identical headstones be cut from it.
Hostingley Colliery	West Yorkshire	No reliable opening date has yet been located.–1880	Coal	(well documented example) The pit worked the Coal Measures of the West Yorkshire coalfield south of the Calder around Thornhill, where the neighbouring Ingham pits took the New Hards, Wheatley and Blocking Bed seams.
Hough Hole Colliery	Cheshire	c. 1803–1925	Coal	(well documented example) Thin Coal Measures seams outcropping on the flank of Kerridge Hill and broken by faulting — worked by drift straight into the seam because they were shallow, and abandoned because they were thin and poor.
Hyde Colliery	Greater Manchester	By 1842–No reliable closure date has yet been located.	Coal	(well documented example) Worked the Two-feet, Peacock, Third and Black seams on measures inclined about 28 degrees, so that the depth to each seam varied greatly across the workings.
Ibstock Colliery	Leicestershire	1825–No reliable closure date has yet been located.	Coal, Fireclay	(well documented example) The record turns on the Upper Main seam at 210 feet and the Lower Main at 376 in the concealed eastern basin of the Leicestershire coalfield, and on the fireclay seam the shafts cut on the way down.
Ireland Colliery	Derbyshire	1876 (sinking from 1872)–1986	Coal	(well documented example) Sunk to the Deep Soft (Hollingwood bed) at 364 yards, with the Blackshale below and the Deep Hard and Piper worked later.
Irthlingborough Ironstone Mine	Northamptonshire	1915 (quarrying); 1918 (underground)–1965	Iron	(well documented example) The Northampton Sand Ironstone was worked here as a single flat-lying Jurassic bed, followed underground by pillar-and-stall — a textbook bedded deposit, and the reason the mine's layout looks nothing like the vein mines that dominate the rest of the archive.
Jackfield Colliery	Shropshire	By 1869–c. 1940	Coal, Fireclay, Brick Clay	(well documented example) Lower Coal Measures outcropping near the Severn, with coal, ironstone and clay lying close enough together to be got from the same shallow workings — seams described as few, thin and shallow, which is why the pits here stayed small.
Jamage Colliery	Staffordshire	Working by 1894; earlier date not established–Still returning 140 people in 1937; closure date not established	Coal	(well documented example) The Bullhurst, Seven Feet and Eight Feet seams worked at Jamage are beds in the north Staffordshire coal measures; the Bullhurst is thick, undulating and prone to spontaneous combustion.
Jenny Gray Colliery	Fife	1854–September 1959	Coal	(well documented example) The record names the Five Feet, Mynheer, Glassee, Lochgelly and Dunfermline Splints, Little Splint, Fourteen Feet, Rough and Parrot seams of the Fife coalfield, worked in turn, with blaes returned alongside the coal in 1915.
Kellingley Colliery	North Yorkshire	1965–18 December 2015	Coal	(well documented example) Up to seven workable coal seams of the Yorkshire coalfield were proved by boring in the 1950s, production beginning from the Beeston seam in 1965.
Kelty Colliery	Fife	Earl of Moray's in the 1850s; Nos. 4 and 5 sinking from 1873–No reliable closure date has yet been located.	Coal	(well documented example) The colliery worked the Coal Measures of the Fife coalfield at Kelty.
Kensworth Chalk Pit	Bedfordshire	1964–Still active	Chalk	(well documented example) The quarry works bedded Upper Cretaceous chalk and is the stratotype for the Kensworth Nodular Chalk Member — the defining reference section for that named bed, which is about as literal an example of working a sedimentary bed as the archive holds.
Killan Colliery	Swansea	First drift opened 1899–1925	Coal	(well documented example) The colliery worked the Penlan and Penclawdd seams above Dunvant, the Penlan dipping steeply north east and outcropping under sandstone, in ground cut by two large faults parallel to the main slant.
Kilrenny Oil Works	Fife	1866–Damaged by explosion 1873; disused to at least 1878	Oil Shale	(historical documentary reference) A works retorting oil shale from a narrow bedded seam in the Calciferous Sandstone measures of eastern Fife, worked with ironstone and coal from the same sequence, as this record's geology describes.
Kimmeridge Oil Shale Workings	Dorset	c. 400 BC–c. 1890	Oil Shale, Limestone, Alum	(well documented example) The Blackstone is a single bituminous bed within the Kimmeridge Clay, worked along its outcrop and then by levels driven along it — a bedded deposit whose thinness and lateral persistence dictated how it had to be won.
Kings Dyke and Must Farm Clay Pits	Cambridgeshire	Brickmaking from the late 19th century; the Kings Dyke pit from the 1920s–Clay extraction ended 1995; the district's pits still worked	Brick Clay	(well documented example) The Lower Oxford Clay, a Jurassic mudstone bed running from Yorkshire to Dorset, worked here for its unusual self-firing quality rather than for any metal or mineral it contains.
Kingseat Colliery	Fife	No. 1 pit c. 1866; Nos 2 and 3 by 1873; Dean Colliery from c. 1902–Old pits 1910; Dean Colliery flooded and abandoned December 1945	Coal, Fireclay, Ironstone	(historical documentary reference) Eleven named Fife coals plus blackband ironstone and fireclay appear in the lists and abandonment plans.
Kingshill No. 3 Colliery	South Lanarkshire	sunk 1946-51 (first major NCB sinking in Scotland)–1974 (winding); abandoned 1975	Coal	(well documented example) Worked Coal Measures seams connected underground to the earlier Kingshill No. 1 and No. 2 workings.
Kinneil Colliery	Falkirk	1892 (Furnace Yard Pit)–1982	Coal	(well documented example) Carboniferous coal seams that continue unbroken beneath the Firth of Forth — the reason a colliery on one shore could be driven through to meet one on the other.
Kirkby Colliery	Nottinghamshire	Sinking 1890-1915–1968	Coal	(well documented example) The colliery worked the Coal Measures of the Nottinghamshire coalfield at Kirkby in Ashfield.
Kiveton Park Colliery	South Yorkshire	1866–1994	Coal	(well documented example) Sunk to the Barnsley seam at just over 400 yards — the bed that drew sinkings across the South Yorkshire and Doncaster coalfields.
Knockshinnoch Castle Colliery	East Ayrshire	shaft sunk 1942–1968 (closed); abandoned 1969	Coal	(well documented example) The mine's own recorded geology explicitly describes working coal seams close to the surface.
Lassodie Colliery	Fife	1859–May 1931	Coal	(well documented example) The eleven pits were sunk successively from the western end of the estate eastwards, each following the bedded West Fife coals until that seam was exhausted — the classic pattern of a bedded deposit worked out block by block.
Leeswood Green Colliery	Flintshire	Early nineteenth century–No reliable closure date has yet been located.	Coal, Cannel Coal	(well documented example) The pit worked cannel and coal in the Flintshire Coal Measures between two north-south faults, the 1923 return naming the Powell seam.
Leeswood Main Colliery	Flintshire	About 1861–No reliable closure date has yet been located.	Coal, Cannel Coal	(well documented example) The pit worked coal and cannel in the Flintshire Coal Measures, the seam undulating without regular dip except to the south.
Lewis Merthyr Colliery	Rhondda Cynon Taf	1850 (Hafod/Coed Cae pits); 1880/1890 (Bertie/Trefor shafts)–1983	Coal	(well documented example) The colliery worked the household and steam coal seams of the Rhondda coalfield through the Bertie and Trefor shafts.
Limeylands Colliery	East Lothian	By 1915–No reliable closure date has yet been located.	Coal	(well documented example) The record names the Four Feet, Five Feet, Nos. 1 and 2 Diamond and Parrot seams of the East Lothian coalfield worked in turn.
Linby Colliery	Nottinghamshire	1873–31 March 1988	Coal	(well documented example) Eight bedded seams worked in succession from the Top Hard down, an unusually wide range for a Leen Valley pit and the reason Linby outlasted the seam it was sunk for.
Lings Colliery	Derbyshire	1840–1896	Coal	(well documented example) Lings worked the Top Hard coal of the north Derbyshire coalfield, the bedded seam that carried the district before the deeper Blackshale was reached for.
Littleburn Colliery	County Durham	Bored 1840; sunk from 20 April 1870–December 1950	Coal, Fireclay	(well documented example) The 1871 Merchant Pit log records the Busty as a bedded seam at 471 feet 8 inches, and the abandonment catalogue names the Hutton, Harvey, Brockwell and Low Main worked in turn through the same Durham Coal Measures sequence.
Llanbradach Quarry	Caerphilly	By 1905, possibly earlier–No reliable closure date has yet been located.	Sandstone	(well documented example) The quarry exposes the Pennant sandstones of the Upper Carboniferous — bedded sedimentary rock whose beds the quarrying cut through, and within which the site's permineralised Westphalian plant fossils occur.
Llandebie Colliery	Carmarthenshire	First slant driven 1904–20 December 1958	Anthracite	(well documented example) The colliery worked the Lower and Upper Pumpquart, Lower Triquart, Stanllyd and Trichwart anthracite seams at the western end of the South Wales coalfield.
Llanhilleth Colliery	Blaenau Gwent	1850s–1969	Coal	(well documented example) House coals of the Ebbw Fach valley close to surface — the Tillery or Red Ash at 200 feet — over the steam coals of the Lower and Middle Coal Measures nearly 400 yards down: the Black Vein at the Nine-Feet horizon, the Meadow Vein and the Lower Black Vein.
Llanymynech Hill Mines and Quarries	Powys	Copper worked from the later Bronze Age–Copper abandoned around 200 AD	Copper, Limestone	(well documented example) The hill is a mass of bedded Carboniferous Limestone, quarried in benches down the open face — the same rock that carried the copper the Bronze Age and Roman miners came for, but worked in the end for itself, as flux and as quicklime.
Llay Main Colliery	Wrexham	Sinking begun 1914, suspended 1917, resumed January 1919, completed April 1921–1966	Coal	(well documented example) The Two Yard, Brassey and Main seams of the Denbighshire coalfield, left unworked until a company was willing to sink 900 yards to reach them.
Lletty Shenkin Colliery	Rhondda Cynon Taf	1843–1922	Coal	(well documented example) The colliery's own returns list six named bedded coal seams worked together in 1910 — Four Feet, Gellideg, Nine Feet, Seven Feet, Two Feet Nine and Yard — each lying on a bed of seatearth within the South Wales Coal Measures.
Lluest Colliery	Bridgend	By 1880–1902	Coal	(well documented example) Its geology field names the No. 3 Rhondda seam of the Pennant succession in the upper Coal Measures, in places only twenty-two inches thick — a bedded seam whose thinness governed how it was worked.
Lofthouse Colliery	West Yorkshire	Shafts sunk 1873-1877–1981	Coal	(well documented example) Bedded Carboniferous coals — and, crucially, two centuries of earlier workings in the same seams whose flooded roadways were the actual hazard.
Loganlea Colliery	West Lothian	About 1890–1959	Coal	(well documented example) The colliery worked the China, Smithy, Wilsontown Main and Lady Morton seams of the Central Scottish coalfield in ground that carries oil shale as well as coal.
Longacres Mine	North Yorkshire	Leased 1865; shafts sunk 1873-75–1954	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Loughrigg Fell Slate Quarry	Cumbria	Working by 1888–No reliable closure date has yet been located.	Slate	(historical documentary reference) A green-slate quarry in the cleaved volcanic tuffs of the Borrowdale Volcanic Group, worked along an imposed cleavage rather than the original ash bedding, as this record's geology describes.
Loveston Colliery	Pembrokeshire	1932–27 July 1937	Anthracite, Coal	(well documented example) Anthracite seams of the Pembrokeshire coalfield, heavily folded and faulted, worked by a slant driven into the measures; the unmapped old workings that flooded the mine lay in the same beds above and to the rise.
Lynemouth Colliery	Northumberland	1927–1994	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the Great Northern Coalfield, worked out beneath the North Sea; no individual seam is named in any source located.
Magheramorne Quarry	County Antrim	Early 19th century–1980 (quarrying)	Chalk, Limestone	(well documented example) The quarry works a named, mapped succession of chalk members of the Ulster White Limestone Formation — Cloghfin Sponge Beds, Creggan, Boheeshane, Larry Bane, Ballintoy and Glenarm — beneath basalt overburden, a bedded deposit whose dip and thickness set the shape of the pit.
Mainsforth Colliery	County Durham	1873; reopened from c. 1900–6 December 1968	Coal	(well documented example) Mainsforth worked the Durham Coal Measures as a stack of named seams — Five Quarter, Brockwell, Bottom Hutton, Harvey, Main Coal and the Busties — taken in turn as the shafts were deepened.
Mansfield Colliery	Nottinghamshire	1904-5–Early 1988	Coal	(well documented example) A deep shaft mine on the concealed coalfield, sunk 585 yards to the Top Hard and later working the High Hazles and Deep Soft seams.
Mapperley Colliery	Derbyshire	1872–27 March 1965	Coal	(historical documentary reference) The Deep Hard, Deep Soft, Kilburn and Piper seams are named in the Lists of Mines.
McLaren Colliery	Caerphilly	1897–1969	Coal	(well documented example) The record describes the colliery working the steam-coal seams of the Rhymney Valley in the eastern South Wales Coalfield — bedded seams in the Coal Measures.
Meadow Colliery, Haigh	Greater Manchester	1880 (museum)–1925 (museum)	Coal	(historical documentary reference) The Arley, King and Yard coals are named in the Lists; Haigh cannel is recorded from 1540.
Meiklehill Colliery	East Dunbartonshire	Working by 1866; returned to the Inspectors from 1894–Last return 1923; closure date not established	Coal, Ironstone	(well documented example) The Coking, Main and Wee seams worked at Meiklehill are beds in the Scottish Coal Measures of the Kelvin valley, with ironstone in the same sequence.
Melton Bottom Chalk Pit	East Riding of Yorkshire	1920s–Still active (working quarry; the southern pit is disused)	Chalk	(well documented example) The quarry works bedded Cretaceous Chalk of the Yorkshire Wolds, and its southern section is the type locality of the Welton Chalk Formation — the reference exposure defining that bedded unit.
Michael Colliery	Fife	1892 (sunk); 1898 (production)–1967	Coal	(well documented example) The colliery worked a sequence of Fife coalfield seams — Chemiss, Barncraig, Bowhouse, Branxton, Dysart Main and Lower Dysart among them — some eighty-four feet of coal in aggregate across sixteen seams pierced by its shafts.
Middle Duffryn Colliery	Rhondda Cynon Taf	1843–Late 1880s; pumping and ventilation to at least 1896	Coal	(well documented example) The shafts were sunk to bedded steam-coal seams of the South Wales sequence at 167 yards, with No. 1 later deepened to the Gellideg at 293 yards.
Middridge Colliery	County Durham	Sinking began 1872–1914	Coal	(well documented example) The colliery worked the Harvey, Brockwell, Busty and Four Foot coking seams of the south-west Durham Coal Measures, the Busty here split by a seggar band of fireclay.
Midland Quarry	Warwickshire	1876–No reliable closure date has yet been located.	Diorite, Sandstone	(historical documentary reference) Scoped honestly: the quarry worked Cambrian sandstone alongside the diorite, but the rock that gave it its value is igneous rather than bedded, so the link covers only the sedimentary half of the face.
Milfraen Colliery	Torfaen	1843; new shaft 1865–1933	Coal	(well documented example) The record names the Old Coal seam at 236 yards and the No. 2 and Yard seams worked in 1923, on the high northern rim of the South Wales coalfield where the measures reach the surface on open mountain.
Minnie Pit	Staffordshire	1881 (sinking from 1883 on one account)–April 1930	Coal	(well documented example) Five thick seams from the Four Feet to the Bullhurst, the last gassy and liable to spontaneous combustion, with the Bullhurst rearing to the surface at Miles Green.
Moira Collieries	Leicestershire	1804–1990	Coal, Fireclay	(well documented example) The Moira Main Coal, a bedded seam up to five metres thick at about 215 m, worked from successive shafts sunk along it as the face moved away from the older ones.
Moorfield Colliery	Lancashire	c. 1881–Closed except for pumping, 21 January 1949	Coal	(well documented example) Moorfield worked a thin bedded seam of the Lancashire coalfield, 24 to 26 inches thick at 293 yards.
Moorgreen Colliery	Nottinghamshire	1865 (coal from 1871)–July 1985	Coal	(well documented example) Worked the Deep Soft, Deep Hard, Second Waterloo, Tupton and Blackshale seams of the Middle Coal Measures in turn over 120 years.
Mosley Common Colliery	Greater Manchester	1868–1968	Coal	(well documented example) Sunk specifically to reach Middle Coal Measures seams — Crombouke, Brassey, Seven Foot and Trencherbone — that lay below the reach of the older Stonehouse Pits, and later deepened again to follow the measures south beneath the Permian cover.
Mostyn Colliery	Flintshire	13th century–1884	Coal	(well documented example) Worked the North Wales coal measures where they run out beneath the Dee estuary — the same seams later pursued at Point of Ayr — on the pillar and stall method, coal left in pillars to hold the roof.
Muirkirk Collieries	East Ayrshire	1787–1923 (ironworks); coal working continued in the district	Coal, Ironstone	(well documented example) Muirkirk worked bedded Carboniferous coal seams and blackband ironstone lying with limestone in the same measures, the combination that justified the ironworks.
Mynydd Newydd Colliery	Swansea	1843–1 July 1955	Coal	(well documented example) The Six-Feet seam at over nine feet thick is why a chapel could be cut and stood up in: a bedded coal tall enough to leave a room behind when it was worked out.
Nailstone Colliery	Leicestershire	1862–1967 (coal winding); site worked on to 1991	Coal, Fireclay	(well documented example) Concealed Coal Measures beneath the New Red Sandstone, the Upper Main and Lower Main worked by longwall on a 1 in 14 dip, each with its own fireclay bed beneath.
New Boston Colliery	Merseyside	c. 1854 (museum: 1880)–1907 or 1910; pumping only in 1910	Coal	(historical documentary reference) The Delf, Nine Feet and Ravenhead seams are named in the Lists.
New Haden Colliery	Staffordshire	By 1901–1943	Coal	(well documented example) New Haden worked the Woodhead coal of the small Cheadle coalfield, a seam thick enough to give the colliery its Klondyke nickname.
New Hawne Colliery	West Midlands	1864–1920s	Coal	(well documented example) The record turns on the thickness of a single bedded seam — thirty feet over most of the take — and on the consequence of extracting it, the ground above falling into the void as the coal was drawn.
New London Colliery	Nottinghamshire	c. 1874–1937	Coal	(well documented example) A Middle Coal Measures colliery of the Erewash valley; its company's seams were the Deep Hard, Deep Soft, Tupton, Silkstone and Top Hard.
New Rock Colliery	Somerset	1819–September 1968	Coal	(well documented example) One of the few places in the Somerset field where the Lower and Middle Coal Measures were worked, in a syncline where thin seams are tightly folded and faulted.
New Stubbin Colliery	South Yorkshire	Sinking begun 1913–6 July 1978	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the South Yorkshire coalfield on the Wentworth estates; no individual seam is named in any source located.
Newcraighall Colliery	Midlothian	1897 ('the Klondyke')–1968	Coal, Cannel Coal	(well documented example) Worked the Great Seam, South Parrot, Stairhead and North Greens (Jewel) Coal Measures seams; Stairhead also yielded ironstone.
Niddrie Colliery	Midlothian	By 1874–By 1968	Coal	(well documented example) Midlothian Coal Measures on the northern edge of the basin, the company following the same seams outward from Niddrie to Newcraighall and Woolmet as the nearer ground gave out.
Nixon's Navigation Colliery	Rhondda Cynon Taf	1860–1940	Coal	(well documented example) Sunk to the Four Feet seam at 365 yards and deepened in the late 1880s to the Nine Feet — the named South Wales steam coal succession, one shaft eventually winding from both seams.
Norman's Quarry	Dorset	Early 20th century–Second World War; reopened 1995	Limestone	(well documented example) The quarr worked the Purbeck limestone beds beneath an overburden that had to be shafted through, which is the form Purbeck stone working takes.
North Blaina Colliery	Blaenau Gwent	Probably about 1860 as the Rising Sun Pit; returned from 1890–About 1923	Coal	(well documented example) The colliery worked the Three Quarter, Elled and Big Vein seams of the western valleys of Monmouthshire above Blaina.
North Staveley Colliery	South Yorkshire	Sunk in the 1840s as Aston Colliery–No reliable closure date has yet been located.	Coal	(historical documentary reference) A South Yorkshire Coalfield pit working Coal Measures seams in the near-horizontal beds this deposit type describes, on ground where the same seams run under two counties.
North Steelend Colliery	Fife	By 1880; reopened 1957–1896 (colliery); 1965 (private mine)	Coal	(well documented example) The Gas, Upper Eight Feet and Smithy coals and the Steelend blackband ironstone in the Limestone Coal Group north of Saline.
Nunnery Colliery	South Yorkshire	1868–August 1953	Coal	(well documented example) The Silkstone seam at Nunnery dipped to the north-east at about four inches in the yard, so that the whole of the workings lay to the dip of the shaft and had to be reached by an inclined main plane — a working consequence of the bedded, gently dipping Coal Measures this record describes.
Oaks Colliery	South Yorkshire	shaft sunk early 1830s–workings absorbed into Barnsley Main Colliery from 1929	Coal	(well documented example) The mine's own recorded geology explicitly describes the Carboniferous Barnsley Seam of the Yorkshire Coalfield.
Old Burghclere Lime Quarry	Hampshire	1885–April 1938	Chalk	(well documented example) The quarry cut bedded Cretaceous Chalk of the north Hampshire downs, burnt on site for lime rather than dressed as building stone.
Old Mills Colliery	Somerset	1860–1966	Coal	(well documented example) Thin Coal Measures seams of the Somerset field, folded and faulted by the Variscan movements — the reason two shafts here went a thousand feet and more.
Orgreave Colliery	South Yorkshire	1851–October 1981	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the South Yorkshire coalfield; no individual seam is named in any source located, so the link is at coalfield level.
Pantyffynnon Colliery	Carmarthenshire	1902 (earlier workings from the 1850s)–31 January 1969	Anthracite, Coal	(well documented example) The record names the Stanllyd, Rock, Upper and Lower Pumpquart, Little Vein and Brynlloi seams with their thicknesses, and turns on the slant having to be driven 500 yards to reach the Stanllyd.
Pelsall Hall Colliery	West Midlands	By 1872–1892	Coal	(well documented example) The colliery worked the shallow bedded coal of the South Staffordshire coalfield in ground already honeycombed by older workings, which is what let the 1872 inrush happen.
Pennyvenie Colliery	East Ayrshire	Production from 1872–1978	Coal	(well documented example) A Coal Measures colliery on the eastern side of the Doon Valley, working bedded seams versatile enough to be sold as house, gas, manufacturing and steam coal from the same pit, in the same sequence that carried the blackband ironstone the Dalmellington Iron Company had come for.
Penylan Quarry	Cardiff	By the mid-19th century–Not worked since the 19th century	Sandstone	(historical documentary reference) A building-stone quarry worked into bedded Silurian marine mudstone, valued since for the shelly fauna preserved through those beds rather than for anything concentrated in them.
Pirnie Colliery	Fife	1856–c. 1920s (date not established)	Coal, Cannel Coal	(well documented example) The Parrot or gas coal and the Thirty-Inch, Wood, Diamond, Bowhouse and Dysart Lower seams of the Methil district.
Pitstone Chalk Quarry and Cement Works	Buckinghamshire	1937–1991	Limestone, Chalk	(well documented example) Worked the Chalk Marl and Grey and Middle Chalk of the Chiltern escarpment as bedded deposits.
Plas Power Colliery	Wrexham	1875 (coal from 1877)–1938	Coal	(well documented example) Worked the Brassey, Crank, Powell and Drowsall seams of the Denbighshire coalfield for gas, house and steam coal.
Pochin Colliery	Blaenau Gwent	Sunk from 1876; first coal 1881–1964	Coal, Ironstone	(well documented example) The colliery's returns name bedded South Wales seams worked together — the Big Vein, Yard, Old Coal and Upper and Lower Rhas Las — with ironstone raised from the same measures.
Pont y Fenni Quarry	Carmarthenshire	No reliable opening date has yet been located.–Disused by 1985, when the site was notified	Mudstone	(surviving physical example) A quarry and road cutting valued for the bedded Arenig section they expose and the fauna preserved through it, undeformed where the same rocks elsewhere in South Wales were folded and faulted, as this record's geology describes.
Pontyberem Colliery	Carmarthenshire	1845–No reliable closure date has yet been located.	Anthracite	(well documented example) Pontyberem worked the Lower Pumpquart and Triquart seams of the west Wales anthracite coalfield, reached by slants driven down into the dipping coal.
Pooley Hall Colliery	Warwickshire	1850–1965	Coal	(well documented example) Warwickshire coals at the northern end of the field, worked closely enough beneath the surface that several of the pools in the country park above are subsidence hollows.
Poynton Collieries	Cheshire	By 1600–30 August 1935	Coal	(well documented example) A stack of named bedded coals — Four Foot, Five Foot, Ten Foot, Gees, Reform, Accommodation and Arley — worked in turn, each thinner and dearer than the last, which is exactly the sequence Greenwell’s 1892 report describes running out.
Prestongrange Colliery	East Lothian	12th century; the final colliery's first shaft sunk 1830–1962	Coal, Fireclay	(well documented example) Carboniferous coal seams underlain by fireclay — the fossil soil of the coal forest — which is why the colliery ran a brickworks on the same site.
Pretoria Pit (Hulton Colliery Bank Pit)	Greater Manchester	Shafts sunk 1900–01–14 April 1934	Coal	(well documented example) Five named coal seams worked from one pair of shafts at depths from 146 to 434 yards, dipping south at about 1 in 5.5 — a clear illustration of how a bedded, dipping deposit forces a colliery to develop separate horizons from the same shafts.
Purbeck Marble Quarries	Dorset	Worked since Roman times; medieval peak 12th-14th centuries–Commercial extraction ceased in the 1990s	Limestone	(well documented example) A fossil-rich freshwater limestone bed of the Purbeck Group, worked from narrow shafts sunk to follow the bed once the surface outcrop was exhausted.
Purfleet Chalk Pits	Essex	By 1554–Early 1920s (cement works and quarry)	Chalk	(well documented example) The pits cut a bedded sequence — Chalk overlain by Thames terrace sands and gravels of the Corbets Tey Formation — and the whole is folded into the Purfleet anticline, so the dip of the beds against that fold governs what is exposed in each pit.
Pwllbach Colliery	Neath Port Talbot	By 1894–No reliable closure date has yet been located.	Coal, Anthracite, Fireclay	(well documented example) The record names the Red Vein of the northern outcrop of the South Wales coalfield as the seam worked, with fireclay raised from the same workings until about 1900.
Pye Hill Colliery	Nottinghamshire	1874–August 1985	Coal	(well documented example) Worked the Tupton and Silkstone (Black Shale) seams of the Middle Coal Measures on an exposed part of the coalfield where the measures reach the surface.
Quarter Colliery	South Lanarkshire	By 1841, possibly earlier–1930	Coal	(historical documentary reference) The record places the colliery in the bedded Coal Measures of the Lanarkshire coalfield in the Midland Valley, where coal and ironstone were worked together; no individual seam is named in any source located.
Reigate Caves	Surrey	18th century or earlier; Tunnel Road mines after 1823–early 20th century	Silica Sand	(well documented example) The silver sand worked here is a bed within the Folkestone Formation of the Lower Greensand, followed underground where it lies beneath cover.
Rhigos Colliery	Neath Port Talbot	1919, as Peacock–February 1965	Coal	(well documented example) The record names five bedded anthracite seams worked here — the Yard, Lower Yard, Bluers, Peacock and Lower Peacock — reached by drifts driven into the outcrop on the valley sides rather than by sinking.
Riddochhill Colliery	West Lothian	1890–1968; abandoned 1969	Coal	(well documented example) The colliery worked named seams of the Central Scottish coalfield — the Jewel, Main, Balbardie, Smithy and Wilsontown Main — in Livingston parish.
Rigg Head Quarry	Cumbria	Working by 1930–No reliable closure date has yet been located.	Slate	(historical documentary reference) A working in the cleaved volcanic tuffs of the Borrowdale Volcanic Group, where the slate splits along a cleavage imposed across the original ash beds rather than along the bedding itself, as this record's geology describes.
Ripley Colliery	Derbyshire	1846 (museum); 1854 or 1863 (local histories)–October 1949	Coal	(historical documentary reference) The Deep Hard, Deep Soft, Tupton and Silkstone seams are named in the Lists of Mines.
Robin Hood Colliery	West Yorkshire	1854–1960s	Coal	(well documented example) The record names the Beeston, Silkstone and Little seams of the Yorkshire Coal Measures worked in turn at the Jane and Bye pits.
Roddymoor Colliery	County Durham	1844–10 August 1963	Coal, Witherite, Fireclay	(well documented example) The record lists five bedded Coal Measures seams stacked within 34 fathoms of the surface at Roddymoor — Main Coal, 'B', Five Quarter, Ballarat and Yard — with their individual thicknesses and depths from Whellan's 1894 Directory.
Rose Heyworth Colliery	Blaenau Gwent	Sunk 1872; first coal 1874–1985	Coal	(well documented example) The colliery worked named seams of the eastern South Wales coalfield — the Old Coal, Three Quarters, Big, Elled, Black Vein and Meadow Vein — in the Ebbw Fach valley.
Rosedale Ironstone Mines	North Yorkshire	1857 (west side); 1859 (east side)–1929 (final closure; briefly reopened 1919-26)	Iron	(historical documentary reference) The ironstone lies within the Middle Jurassic Cleveland Ironstone Formation, a stratabound sedimentary deposit.
Rosehall Colliery	North Lanarkshire	1855 (deaths recorded from 1853)–September 1940	Coal, Fireclay, Ironstone	(historical documentary reference) Nine named Lanarkshire Coal Measures seams and the Blackband ironstone are listed in the Lists of Mines.
Roslin Colliery	Midlothian	c. 1876; re-sunk 1901-3–1969	Coal	(well documented example) Several thin Coal Measures seams of the Midlothian basin worked in rotation — Peacock, Corbie, Glass, Splint, Flex, South Parrot, North Greens, Beattie and Craigie — with ironstone returned alongside the coal in 1920 and shale feeding the brickworks on the same site.
Roundwood Colliery	South Yorkshire	Early 1860s–Early 1960s	Coal	(well documented example) A South Yorkshire Coalfield pit working Coal Measures seams — the Barnsley, Parkgate and Silkstone sequence named in this record's geology section — in the near-horizontal beds characteristic of the deposit type.
Rumney Quarry	Cardiff	Opened in the 19th century–Closed in the 1920s	Limestone, Sandstone	(surviving physical example) A quarry whose value now is the bedded Silurian section it exposes — mudstones with thin sandstone bands beneath the Rhymney Grit, as this record's geology describes.
Rutland Ironstone Quarries	Rutland	1882–1973 (last ore to Corby 1980)	Iron	(well documented example) A bedded low-grade Jurassic ironstone under 60-100 ft of cover — shallow enough to strip, but only with some of the largest excavating machines ever built in Britain.
Saint Vincent's Colliery	Forest of Dean	Licensed 1844–No reliable closure date has yet been located.	Coal, Brick Clay	(well documented example) The record turns on the Upper and Lower Trenchard veins, the lowest coals of the Forest of Dean basin, and on the seatearth clay beneath them proving more valuable than the coal itself.
Scotgate Ash Quarry	North Yorkshire	By 1351–1915	Sandstone	(well documented example) The quarries worked the Libishaw Sandstone of the Millstone Grit series, a thin-bedded micaceous sandstone whose even bedding yielded flags up to sixteen square feet.
Seaham Colliery	County Durham	Sinking begun 13 April 1849; production from 1853–54–1988 (merged with Vane Tempest, 1983)	Coal, Fireclay	(well documented example) Seven named seams of differing thickness worked from one set of shafts over 140 years, from the 5-foot Main coal to the 3-foot Harvey.
Seymour Colliery	Derbyshire	Sinking began 1855; in production 1858–1918	Coal	(well documented example) The Top Hard is a bed in the east Derbyshire coal measures and the only seam Seymour worked.
Sharlston Colliery	West Yorkshire	Opened 1858; shafts sunk 1865–July 1993	Coal	(well documented example) The record names the Coal Measures seams worked — Haigh Moor, Kent Thick, Silkstone, Stanley Main, Birkwood — bedded seams, the deposit type this record describes.
Sherdley Colliery	Merseyside	Established 1872-3; in the Mines List from 1873–Coal working ceased 1944; pumping continued	Coal	(well documented example) The Main Delf, Potato Delf, Four Feet and Yard seams worked at Sherdley are beds in the St Helens part of the Lancashire coalfield.
Sheriff Hill Colliery	Tyne and Wear	By 1793–By 1895-97	Coal	(well documented example) Fifteen seams passed in the Isabella Pit, the High Main at 60 fathoms and the Hutton at 125, with the Bensham between; the High Main crops out in the Low Fell quarry.
Sherwood Colliery	Nottinghamshire	Sinking began 1901-2; first coal September 1902–January 1992	Coal	(well documented example) The Top Hard, Dunsil, Deep Soft, Deep Hard, Piper, Yard and Black Shale worked at Sherwood are beds in the Nottinghamshire coal measures.
Shireoaks Colliery	Nottinghamshire	1859–May 1990	Coal	(well documented example) Worked the Top Hard seam, the Nottinghamshire name for the Barnsley Bed — the same bed sunk to at Kiveton Park and across the Doncaster coalfield.
Shortwood Colliery	South Gloucestershire	Thought to be late 18th century; new shaft 1871–1936, with Parkfield	Coal	(well documented example) The Hard Vein worked at Shortwood is a bed in the Bristol coalfield, one of the upper series of veins also taken at Parkfield alongside the Top, Hollybush and Great.
Shotton Surface Mine	Northumberland	Permitted 2007–Summer 2020	Coal, Fireclay	(well documented example) The mine worked the Coal Measures of the Northumberland coalfield, taking shale and fireclay alongside the coal.
Shuttle Eye Colliery	West Yorkshire	1862–1973	Coal	(well documented example) The Beeston (Top Beeston or Shertcliffe) and Black Bed seams below the Blocking, New Hards and Wheatley Lime, with the shallow Joan and Flockton Thick above.
Six Bells Colliery	Blaenau Gwent	Shafts sunk from 1892–1988	Coal	(well documented example) Worked the South Wales steam coal measures — bedded Carboniferous seams whose freely released firedamp was the coalfield's standing hazard and the direct cause of the 1960 explosion.
Slapewath Ironstone Mine	North Yorkshire	1864–1906	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Smarts Quarry	Carmarthenshire	No reliable opening date has yet been located.–Disused by 1987, when the site was notified	Sandstone	(surviving physical example) A quarry valued for the bedded Namurian section it exposes and for the trace fossils preserved on one of its bedding surfaces, as this record's geology describes.
Smeaton Colliery	Midlothian	Sinking and production from 1903–1978	Coal	(well documented example) Smeaton worked coal seams of the Midlothian coalfield; the sources read name none of them individually.
Smelt Colliery	Wrexham	1790–1967	Coal, Fireclay	(well documented example) The record turns on the Main coal and the fireclay seam beneath it being worked together from the same levels, the fireclay outlasting the coal as the product that paid.
Sneyd Colliery	Staffordshire	Early 19th century–July 1962	Coal, Fireclay, Ironstone	(well documented example) The Sneyd pits worked a stack of named Middle Coal Measures seams — Bowling Alley, Cockshead, Banbury and the rest — with ironstone and fireclay from the same sequence, the pattern this record describes.
Snowdown Colliery	Kent	Sinking from 1907; first coal 1912–1987	Coal	(well documented example) Snowdown worked Coal Measures seams concealed beneath deep younger cover, the reason for the shafts’ depth and their water problems.
Snydale Colliery	West Yorkshire	Shafts sunk from 1863–Coal drawing stopped August 1965	Coal	(well documented example) The Haigh Moor and Stanley Main seams, and the ganister returned in 1915, are beds in the Middle Coal Measures of the West Yorkshire coalfield.
Solsgirth Colliery	Clackmannanshire	opened 1965–closed January 1990 (retained afterward for Castlebridge Colliery ventilation)	Coal	(well documented example) Worked the Hirst Coal Measures seam, linked underground to the neighbouring Bogside and Castlehill collieries.
South Leicester Colliery	Leicestershire	Sinking from January 1876–1983 (merged with Bagworth)	Coal	(well documented example) The colliery worked the Upper Main, Lower Main and Nether Lount seams of the Leicestershire coalfield, the last of them continuous enough into the Ellistown sett for one tunnel to join the two mines.
South Liberty Colliery	Bristol	1748–1925	Coal	(well documented example) Carboniferous coal measures on the faulted northern edge of the Somerset basin — broken ground that made the Bristol field small, awkward and expensive to work.
South Skelton Mine	North Yorkshire	Leased 1865; shafts sunk and mining from 1872–1954	Ironstone	(well documented example) The Cleveland Main seam worked here is a bedded sedimentary ironstone in the Lias.
Spa Mine	North Yorkshire	1864–1886 (lease ran to 1904)	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Spa Wood Mine	North Yorkshire	Leased 1853; production from 1864–1930	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Speedwell Colliery	Bristol	Worked from the early 18th century–1936	Coal	(historical documentary reference) The record describes the narrow seams of the Bristol coalfield and the Great Vein series found in the 1830s — bedded coal seams, the deposit type this record describes.
Sprinkle and Nash Colliery	Pembrokeshire	1855–1865	Coal, Anthracite	(well documented example) Sprinkle and Nash worked seams of the Pembrokeshire coalfield, whose coal is high-quality anthracite in seams that are mostly thin.
St John's Colliery	Bridgend	Sunk from 1908; first coal 1910–22 November 1985	Coal	(well documented example) Middle and lower Coal Measures of the western South Wales coalfield at 385 yards, worked down the sequence over time from the Upper New, Seven Feet and Lower Six Feet to the Lower Nine-Feet and Gellideg, beneath a shallow Victoria seam already exhausted by the earlier Cwmdu Colliery.
Stanghow Mine	North Yorkshire	Shafts sunk 1871; production from 1872–Last stone 1921; abandoned 1928	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Stonesfield Slate Mines	Oxfordshire	Worked since at least the Roman period–1911	Limestone	(well documented example) The Stonesfield Slate is a sedimentary limestone bed reached by shaft and horizontal gallery like any bedded deposit, though an unusually localised one: barely 1.8m thick and confined to a roughly 1.5km oval around the village, rather than the mile-scale extent typical of a coal seam or ironstone bed of this type.
Strelley Colliery	Nottinghamshire	Later 16th century–Later 17th century	Coal	(well documented example) Shallow bell pits worked on the exposed coal of the Nottinghamshire field, the shape of the workings following directly from how near the surface the seam lay.
Sundrum Colliery	South Ayrshire	Dalmellington pits by 1894; NCB mine sunk 1952–Earlier mine 1933; NCB mine 1961	Coal	(well documented example) The Ell, Main, Major and Ayr Hard seams worked at Sundrum are beds in the Ayrshire coal measures.
Sutton Manor Colliery	Merseyside	1906–1991	Coal	(well documented example) The record names the Coal Measures seams the pit worked — Crombouke, Florida, Trencherbone, Wigan Five Feet and Yard — bedded coal seams, the deposit type this record describes.
Swinden Quarry	North Yorkshire	1899–Still active	Limestone	(well documented example) Works the bedded Carboniferous limestone of Wharfedale, the same mass that forms the pavements and scars of the surrounding Dales.
Talar Wen Quarry	Carmarthenshire	No reliable opening date has yet been located.–Disused by 1993, when the site was notified	Limestone	(surviving physical example) A quarry valued now for the bedded Llandeilo limestone section it exposes and the fauna through it, the beds decalcified near surface so that the fossils come out of them readily, as this record's geology describes.
Talwrn Colliery	Wrexham	Working by 1857; Coedpoeth coal from 1790–No reliable closure date has yet been located.	Coal	(well documented example) The colliery worked the shallow Denbighshire coalfield seams at Coedpoeth, in ground that carried firedamp in quantity.
Teversal Colliery	Nottinghamshire	Sinking began 1868–No reliable closure date has yet been located.	Coal	(historical documentary reference) Scoped honestly: the record establishes that Teversal worked the concealed coalfield on the Nottinghamshire and Derbyshire border for furnace coal, but the Lists of Mines name no seam for it and no source read here does either.
Thorne Colliery	South Yorkshire	January 1925–1956	Coal	(well documented example) Sunk to the Barnsley Bed, proved by borehole at 916 yards and about nine feet thick, with an inset at the Kent's Thick or High Hazel seam at 863 yards; the overlying unconformable strata were identified in 1966 as the source of the water that defeated the pit.
Thrislington Colliery	County Durham	Boring from 1835; sunk from 15 April 1840–4 March 1967	Coal	(well documented example) The Jane Pit's 1867 sinking log records the coals as bedded seams within a repeated sandstone and shale sequence, and Whellan's 1894 Directory gives the Harvey four feet thick at 103 fathoms with the Low Main, Hutton and Brockwell beneath it.
Tibshelf Colliery	Derbyshire	Bottom Pits deepened 1864-65; Top Pits sunk 1891–Bottom Pits 1936; Top Pits 1939	Coal	(well documented example) The Tupton, Deep Hard and Silkstone seams worked at Tibshelf are beds in the East Derbyshire coal measures, outcropping on the escarpment and dipping east under the Permian.
Tinsley Park Colliery	South Yorkshire	1819–Early 1943	Coal	(well documented example) The record names five bedded seams worked over the colliery's life — the Wath Wood, High Hazels, Parkgate, Haigh Moor and Barnsley — in the Coal Measures of the South Yorkshire coalfield, the shallowest of them worked at first from bell pits.
Tonge Colliery	Greater Manchester	1854–1930 (abandoned 1932)	Coal	(historical documentary reference) Bolton district Coal Measures: Bancroft, Five Quarters and Trencherbone seams in the Lists of Mines.
Torr Works	Somerset	1930s–Still active	Limestone	(well documented example) Works well-bedded Carboniferous Limestone dipping consistently southwards, with Jurassic oolitic limestone resting on the tilted older beds as an angular unconformity.
Tower Colliery	Rhondda Cynon Taf	coal worked from c. 1805; Tower drift sunk 1864–1994 (British Coal); reopened 1995; closed for good 2008	Coal	(well documented example) The mine's own recorded geology explicitly describes Carboniferous coal seams of the South Wales Coalfield.
Treeton Colliery	South Yorkshire	Sinking begun 1875–7 December 1990	Coal	(well documented example) The record names four bedded seams worked here — the Barnsley, High Hazels, Wathwood and Swallow Wood — in the Coal Measures of the South Yorkshire coalfield.
Trimdon Grange Colliery	County Durham	May 1845–16 February 1968	Coal	(well documented example) The colliery worked a long succession of named Durham Coal Measures seams — Five Quarter, Main, Low Main, Harvey, Busty, Hutton, Maudlin, Brockwell and Tilley — a textbook case of a mine following bedded deposits progressively downwards.
Trimsaran Colliery	Carmarthenshire	Working by 1896; earlier mining in the area from the 1600s–April 1954	Anthracite, Fireclay	(well documented example) The Big Vein, Green, Yard, Two Feet and Gregog seams worked from the Trimsaran drifts are beds in the anthracite measures at the western end of the South Wales coalfield, with fireclay in the same sequence.
Trowell Moor Colliery	Nottinghamshire	By 1887–No reliable closure date has yet been located.	Coal	(well documented example) Worked the Kilburn seam with the Furnace Coal and Tupton, the same deep coals its sister pit at Cossall took, in a parish whose shallow measures had earlier been worked by bell pits.
Tunstead Quarry	Derbyshire	1929–Still active	Limestone	(well documented example) A quarry worked in named, mapped limestone formations — the Bee Low Limestone over the Woo Dale Limestone — whose bedded character and exceptional purity are what make the deposit worth working at this scale.
Ty Trist Colliery	Blaenau Gwent	1834–1959	Coal, Ironstone	(well documented example) The record names the Elled or Two-Feet-Nine seam at 75 yards, the Yard at 100 and the Old Coal at 200, with the Rhas Las, Big Vein and Little Yard added by 1923 and ironstone returned alongside the coal.
Tymawr Colliery	Rhondda Cynon Taf	No reliable sinking date has yet been located.–June 1983	Coal	(well documented example) The colliery worked the steam coal seams of the Rhondda at Trehafod, the same measures as Lewis Merthyr beside it.
Tynemount Colliery	East Lothian	Sinking and production from 1924 or 1925–Closed 1952; abandoned 1962	Coal	(well documented example) Tynemount worked coal seams of the East Lothian coalfield; the sources read name none of them individually.
Tyning Colliery	Somerset	1837–1909	Coal	(well documented example) Thin, good-grade Coal Measures seams folded and faulted by the Variscan movements — the reason a Radstock shaft went a thousand feet and more for coal that a Midlands pit reached in a few hundred.
Tynybedw Colliery	Rhondda Cynon Taf	Opened between 1874 and 1878–1933 or January 1935	Coal	(well documented example) The Nine Feet, Seven Feet, Five Feet, Four Feet, Yard, Lower and Bute seams worked at Tynybedw are beds in the steam coal measures of the Rhondda.
Ubberley Colliery	Staffordshire	By 1836–1900 (abandoned by 7 September 1904)	Coal	(historical documentary reference) North Staffordshire Middle Coal Measures: Ten Feet, Ragman, Cockshead, Banbury, Holly Lane, Moss, Bowling Alley, Hardmine, Yard and other seams named in the abandonment catalogue.
Udston Colliery	South Lanarkshire	Begun about 1875–No reliable closure date has yet been located.	Coal	(well documented example) The colliery worked the Ell, Main and Splint coals of the Lanarkshire coalfield in a 150-fathom shaft column, and later the Blackband, Humph, Pyotshaw, Kiltongue and Virgin.
Underwood Colliery	Nottinghamshire	Worked from 1728; 1831, 1855 and 1875 all given–1885	Coal	(well documented example) Underwood worked coal seams of the Nottinghamshire coalfield, shallow enough on this ground to have been taken from the outcrop long before a shaft was sunk.
Valleyfield Colliery	Fife	1908–1978	Coal	(well documented example) Carboniferous coals continuing unbroken under the Firth of Forth — which is what allowed the workings to be driven through to Kinneil on the opposite shore.
Varteg Hill Colliery	Torfaen	Vipond in the area from 1840; Varteg Hill from the 1860s–Merged with Deakins Slope at nationalisation, 1947	Coal, Ironstone	(well documented example) The colliery worked the Jack, Ball Mine, Big, Elled, Meadow, Old Coal, Rock, Three Quarter and Yard seams on the eastern rim of the South Wales coalfield above the Afon Lwyd.
Vauxhall Colliery	Wrexham	1850s (as Kenyon Colliery)–1928	Coal	(well documented example) The record names the Main and Quaker coals and later the Wall, Bench, Seven Feet, Ten Feet, Upper Yard and Stone coal seams of the Denbighshire Coal Measures worked in turn.
Victoria Colliery, Biddulph	Staffordshire	Developed from 1857 (shafts by 1850); renamed Victoria 1900–28 July 1982	Coal, Ironstone	(historical documentary reference) North Staffordshire Coal Measures worked with ironstone for the Biddulph Valley furnaces.
Vron Colliery	Wrexham	Sunk 1806–1930	Coal	(well documented example) The colliery worked the Powell and Drowsell seams of the Denbighshire coalfield at Tanyfron.
Wallsend Colliery	Tyne and Wear	1778–1935	Coal	(well documented example) The record turns on one bedded seam: the High Main, here nearly six feet thick, the uppermost and most valuable of the Tyneside Coal Measures seams and the source of the colliery's reputation.
Wallyford Colliery	East Lothian	1855–1930	Coal, Fireclay	(well documented example) The Great Seam, Jewel, Five Feet and Four Feet worked at Wallyford are beds in the Midlothian coal measures, with fireclay in the same sequence.
Walton Colliery	West Yorkshire	1890 (shafts sunk)–3 December 1979	Coal	(well documented example) Walton worked the bedded coal of the Yorkshire coalfield, shallow enough here to have been taken from the surface since medieval times.
Waterfall Mine	North Yorkshire	1880 or 1892–1901	Ironstone	(well documented example) The Cleveland ironstone is a bedded sedimentary ore in the Lias.
Wath Main Colliery	South Yorkshire	sinking began 1873; reached the Barnsley seam 1876–amalgamated with Manvers Main 1 January 1986; closed 25 March 1988		(well documented example) Worked the Barnsley, Parkgate and Silkstone Coal Measures seams, successively deepened to reach each.
Wearmouth Colliery	Tyne and Wear	1826-1834 (sinking)–1993	Coal	(well documented example) Sunk to reach a coal seam at 1,578 feet, then a further seam at 1,720 feet.
Wednesbury Oak Colliery	West Midlands	Working by 1894; ironworks alongside from 1820–1908-1909	Coal, Ironstone	(well documented example) The Thick Coal and the ironstone measures among it are sedimentary beds of the South Staffordshire coalfield, lying close enough to the surface to be worked from shallow pits.
Weetslade Colliery	Tyne and Wear	1903–10 September 1966	Coal	(well documented example) The sinking record lists six named seams between 538 and 1,139 feet within Coal Measures sandstone, mudstone and fireclay; the Bensham as worked was a 5-foot seam split by a stone band, dipping 1 in 22.
Wellington Pit	Cumbria	1840–1933	Coal	(well documented example) Bedded Carboniferous coals of the West Cumberland field, followed out beneath the Irish Sea.
Wellsways Colliery	Somerset	Working by 1839; sinking date not established–Last return 1896; closure date not established	Coal	(well documented example) The Great, Top Little, Middle, Sliving, Under Little and Bull seams worked at Wellsway are beds in the Somerset coalfield, under their local names.
Wentworth Silkstone Colliery	South Yorkshire	Shafts 1856; drift mine opened June 1911–Summer 1978	Coal	(well documented example) The Silkstone, Flockton, Thorncliffe, Fenton and Whinmoor seams worked here are beds in the South Yorkshire coal measures, each driven into in turn as the last was exhausted.
West Pitcorthie Shale Mines	Fife	1866–No reliable closure date has yet been located.	Oil Shale, Ironstone	(well documented example) Workings on a narrow bedded seam of oil shale in the Calciferous Sandstone measures, with ironstone and the Pitcorthie Coal taken from the same sequence, as this record's geology describes.
West Stanley Colliery	County Durham	1832–1936	Coal	(well documented example) Four stacked Carboniferous seams — Tilley, Towneley, Busty and Brockwell — worked from one colliery, which is why the 1909 explosion could reach all four at once.
Westminster Colliery	Wrexham	By 1860–February 1925	Coal	(well documented example) Worked the Brassey, Crank Coal, Powell, Main, Queen and Two Yard seams of the Denbighshire coalfield in the Moss valley.
Westthorpe Colliery	Derbyshire	Sinking from 1923; shaft completed 1924–1984	Coal	(well documented example) The Deep Soft, Thorncliffe and Flockton seams worked at Westthorpe are beds in the north Derbyshire and south Yorkshire coal measures.
Wet Earth Colliery	Greater Manchester	1740s; formal working from 1751–1928	Coal	(well documented example) The mine's own recorded geology explicitly describes working coal seams of the Manchester Coalfield.
Wharncliffe Wood Ganister Mines	South Yorkshire	1860s–Around the end of the Second World War	Ganister	(well documented example) Ganister is a silica-rich bed within the Coal Measures, worked along its outcrop rather than as a vein.
Whatley Quarry	Somerset	1939–Still active	Limestone	(well documented example) Almost all formations within the Carboniferous Limestone are represented in the quarry, from fairly pure oolites to mudstone-rich and cherty limestones, dipping steeply at 60 to 70 degrees and locally overturned on the flank of the Beacon Hill Pericline.
Wheldale Colliery	West Yorkshire	sunk 1868; production from 1870–October 1987		(well documented example) Worked six named Coal Measures seam insets from Warren House (600 feet) to Beeston (1,693 feet).
Whitburn Colliery	Tyne and Wear	May 1879–1968	Coal	(well documented example) Worked the Bensham, Brockwell and Five Quarter coal seams of the Durham Coal Measures, following them out beneath the North Sea — the bedded geology dictating both the room the mine had to work in and the water problem that eventually closed it.
Whitehill Colliery	Midlothian	worked from 1850; leased and developed by Archibald Hood from 1856–1961-62 (sources differ on the exact year)	Coal	(well documented example) Worked Coal Measures seams of the Midlothian Coalfield, the same seams later worked at the neighbouring Carrington and Polton collieries.
Whitrigg Colliery	West Lothian	Sinking and production from about 1900–1972	Coal	(well documented example) The Jewel, Main, China, Balbardie and Smithy seams worked at Whitrigg are beds in the West Lothian coal measures.
Whitwood Colliery	West Yorkshire	Shafts sunk 1871-1878; coal reached December 1876–About 1970	Coal	(well documented example) Whitwood worked a stack of named coal seams in the Middle Coal Measures, each a bed laid down in a Carboniferous delta.
William Pit	Cumbria	Sunk from May 1804; first coal drawn 1805–Ceased production 31 December 1954	Coal	(well documented example) Coal Measures seams — Main Band, Six Quarters, Bannock Band and others — dipping westward beneath the Irish Sea, worked from a shaft standing almost on the beach and followed outward under the water for miles.
Williamthorpe Colliery	Derbyshire	1905 (sinking from 1901)–28 March 1970	Coal	(well documented example) Sunk to the Blackshale under the terms of its lease and working the Tupton, Deep Soft, Ell, Waterloo and Second Piper seams of the Derbyshire Coal Measures.
Willington Colliery	County Durham	1840–1932	Coal, Fireclay	(well documented example) The returns list a closely stacked group of thin bedded seams — B, Ballarat, Brockwell, Harvey, Hutton, Jet, Seggar and Three Quarter — with seggar clay and plateclay raised as products from the beds between them.
Wimblebury Colliery	Staffordshire	Working by 1894; earlier date not established–Still returning 813 people in 1947; closure date not established	Coal, Ironstone	(well documented example) The Deep, Shallow and Six Feet seams worked at Wimblebury are beds in the Cannock Chase coal measures, with ironstone in the same sequence.
Windlestone Colliery	County Durham	1876; shaft completed October 1877–1924	Coal	(well documented example) Windlestone worked the Durham Coal Measures as named seams — Brockwell, Busty and Harvey — the shaft having been put down to the Marshall Green and bored below it.
Winsford Rock Salt Mine	Cheshire	1844–Still active	Salt	(well documented example) Works a rock-salt seam, a stable, solid evaporite bed rather than brine.
Wistow Mine	North Yorkshire	June 1983–13 May 2004	Coal	(well documented example) Worked the Barnsley seam of the concealed Selby coalfield, and it was the behaviour of the beds above that seam — sagging rather than caving as the faces retreated — that opened the voids through which the Permian aquifer drained into the workings.
Witton Park Colliery	County Durham	June 1819–April 1925	Coal	(well documented example) Worked Durham coalfield seams lying unusually close to the surface — shallow enough to be reached at first by drift and shallow pits before the workings were deepened.
Wollaton Colliery	Nottinghamshire	1873-74–Between 1963 and 1966	Coal	(well documented example) The shafts cut the full local series of Middle Coal Measures seams from the Top Hard down to the Piper, of which only the Deep Soft and Deep Hard were worked.
Woodhorn Colliery	Northumberland	Sinking from 1894–1981	Coal	(well documented example) Woodhorn worked Coal Measures seams of the Northumberland coalfield, including the Main Seam and the Low Main.
Woodilee Colliery	East Dunbartonshire	1890–1930	Coal, Ironstone	(well documented example) The Coking and Main seams worked at Woodilee are beds in the Scottish Coal Measures of the Kelvin valley, with ironstone in the same sequence.
Woolmet Colliery	Midlothian	sunk 1898 (Gazetteer for Scotland) or 1904 (RAILSCOT) by the Niddrie and Benhar Coal Company–1966	Coal	(well documented example) Worked Coal Measures seams also later worked at greater depth by the neighbouring Monktonhall complex.
Wyken Colliery	West Midlands	1854–1915	Coal	(well documented example) The Two Yard, Rider, Ell and Slate seams worked at Wyken are beds in the Warwickshire coal measures.
Yesnaby Quarries	Orkney	Millstone quarrying from an unknown early date–Quarrying declined after the Second World War	Freestone	(well documented example) Hard, evenly bedded Devonian flagstones and sandstones of Lake Orcadie, worked here for millstones and, in the basal beds nearby, host to a low-grade placer-type uranium concentration that was prospected but never mined.
Yniscedwyn Colliery	Powys	1872–22 March 1968	Anthracite	(well documented example) The record gives seam thicknesses through the sequence — the Middle Vein at 0.71 to 0.81 metres, the Six Feet at 36 inches, the Gellideg at 21 — and turns on the Big Vein swelling from 11 feet to 70 in places.
Ynisdavid Colliery	Neath Port Talbot	By 1854–1872	Coal	(well documented example) Seven bedded South Wales seams are recorded for the colliery — Big, Five Feet, Lower Four Feet, Balance, Upper Four Feet, Finery and Sulphur — with the 1856 explosion in the Big Vein.
Ynysfeio Colliery	Rhondda Cynon Taf	Level early 1850s; shaft 1856; Nos 3 and 4 sunk 1906–Production ceased c. 1930; pumping only by 1945	Coal	(historical documentary reference) Ten named South Wales Coal Measures seams are recorded across the two pairs of pits.
Ynyshir Colliery	Rhondda Cynon Taf	No. 1 sunk from 1875; coal 1877–1968	Coal	(well documented example) The colliery worked the Rhondda Four Foot, Two Feet Nine, Nos. 1 to 4, No. 2 Rhondda and Six Feet steam coal seams of the Rhondda Fach.
Zetland Colliery	Clackmannanshire	Returned from 1937; sinking date not established–September 1960	Coal	(well documented example) The Coalsnaughton Main and Mill seams worked at Zetland are beds in the Clackmannanshire coalfield.

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