Reclaimed colliery spoil in Bargoed Woodland Park preserves fragments of the Carboniferous vegetation once buried beneath the valley. Ribbed stems, patterned bark and leaf impressions provide a record of ancient coal-swamp plants within a landscape reshaped by mining and restoration.
FIND FREQUENCY – Plant fragments are recorded in shale and other spoil, but the amount of exposed material changes with weathering and vegetation.
CHILDREN – Use established paths and supervise children around slopes, drainage ditches, cycles and sharp shale.
ACCESS – A council-managed public park with signed routes; use lawful parking and keep all service and emergency gates clear.
TYPE – Reclaimed colliery spoil, distinct from the natural bedrock mapped beneath the park.
DIRECTIONS
♦ The original locality is within Parc Coetir Bargod, also called Bargoed Woodland Park, near the fire-station roundabout and the cycle-gate approach. Its reference is ST15839919, or 51.685416, -3.218823.
♦ Use current signed public entrances and lawful parking. Do not follow the old instruction to park beside padlocked service gates or obstruct the fire-station roundabout, emergency access or maintenance routes.
♦ Check current notices before entering a path or approaching exposed spoil. This is not Aberbargoed Grasslands National Nature Reserve, Parc Taf Bargoed or an invitation to search every tip and drainage channel in the wider park.
FOSSIL HUNTING
The most informative pieces are often fine-grained shale with a clear surface impression. Use oblique light to look for repeated plant structures: parallel veins in a strap-like leaf, nodes and longitudinal ribs on a stem, or an orderly pattern of leaf scars. A black line or shiny coal fragment alone is not enough to identify a plant.
The original field account records Cordaites leaves, Lepidodendron, Calamites, Stigmaria, Sigillaria and Sphenophyllum. These names represent the level of identification supported by the field report and photographs, rather than a newly verified species collection. Some are names for detached organs: Stigmaria, for example, describes rooting structures rather than a complete tree.
A Calamites-type stem may show regular joints and ribs, while lycopsid bark impressions can retain repeated leaf-scar patterns. Broad Cordaites-type leaves are recognised by their strap-like outline and parallel veining. Incomplete impressions may lack the combination of features required to separate similar plant organs, so retain a cautious identification where necessary.
Ironstone nodules, coal and shale reflect the mixture of material brought to the surface during mining. A nodule is not guaranteed to contain a fossil. The tip is not an intact geological section, and neither the colour of a block nor the modern map unit beneath it establishes the seam from which a specimen came.
Historical Bargoed mine records include non-marine bivalves from specified underground roofs, but these should not be presented as confirmed park finds. Record any observed fossil at its actual park location. If collecting has been agreed, label loose specimens as colliery spoil with the original seam unknown unless reliable provenance establishes more.
Photograph exposed surfaces with a scale before handling them. Keep matching halves together and avoid scraping carbonaceous films. Do not dig into banks, pry material from planted slopes or disturb drainage channels to create fresh collecting surfaces.
Significant discoveries, geological research and conservation milestones at Aberbargoed.
1897 – Colliery sinking begins
Sinking at Bargoed began, initiating the underground development whose waste would contribute to the later industrial landscape.
1901 – Coal production and shaft development recorded
The town’s historical account dates first coal to 1901, while the geological shaft appendix records the South Pit as sunk in that year. This should not be confused with completion of both shafts.
1903 – North and south shafts completed
The colliery’s north and south shafts were completed in November, according to the recorded industrial history. The workings later supplied coal and waste from multiple underground horizons.
1969 – Mine seams and fossils documented
The revised district geological memoir published detailed Bargoed seam sections, South Pit depths and fossil records from specified underground horizons. These records help interpret the mining context while remaining distinct from later park finds.
1977 – Bargoed Colliery closes
The colliery closed on 4 June. Subsequent clearance and landscaping transformed the former industrial ground and tip into part of a recreational and wildlife landscape.
2004–2008 – Reclaimed colliery landscape recorded as woodland park
Council documents described Parc Coetir Bargod as developed from the Bargoed, Britannia and Gilfach colliery sites. This records the wider park’s reclaimed origin without proving the source of every individual spoil patch.
GEOLOGY
Two different geological records meet at this locality: natural bedrock beneath the park and artificial spoil deposited by mining. Current BGS mapping identifies sandstone of the Hughes Member, within the Pennant Sandstone Formation and Warwickshire Group, at the original guide point. That map assignment does not date or identify every loose fossil in the overlying dump.
The Hughes Member is Asturian and contains green-grey lithic sandstone with thinner mudstone, siltstone, seatearth and coal. The older phrase Hughes Beds describes the same regional interval in historical accounts; it should not be turned into a separate Hughes Formation. The regional thickness and distant reference sections are not thicknesses exposed in the park.
Bargoed also worked older coal-bearing strata of the South Wales Middle Coal Measures Formation. Their mudstone, siltstone, coal, seatearth and ironstone record delta and floodplain environments with peat-forming wetlands and occasional marine incursions. The formation spans the Duckmantian–Bolsovian, but a precise age for a particular spoil specimen requires its original seam or bed to be known.
The mine logs distinguish numerous seams and intervening rocks, and show that seam thickness and splitting vary even within a colliery. Waste from working and development mixed material at the surface. The original guide’s precise source-depth interval is not established by the checked shaft record, so it is not used to assign every fossil to a depth or seam.
The mapped bedrock beneath Bargoed Woodland Park, mixed colliery spoil and separately documented underground seams.
Artificial colliery spoil. Fossil-bearing loose material in the reclaimed park is not an intact vertical succession. A specimen’s present position does not establish its original seam, depth or formation. The underlying mapped bedrock and the mine’s worked coal-bearing strata are therefore described separately.
Historical shaft record across several formations. The South Pit record below crosses upper Pennant and older coal-bearing units. It is placed outside the ranked formation accounts because the whole shaft is not South Wales Middle Coal Measures. Depths describe the historical mine, not an intact section at the park.
Bargoed South Pit shaft record: upper interval. The appendix identifies South Pit at ST15349978, with a surface level of 540 ft OD and a recorded sinking date of 1901. Depths below that collar are Cefn Glas 212 ft 1 in; Brithdir 579 ft 10.5 in; No. 1 Rhondda 879 ft 9 in; an incompletely legible Rhondda label at 1065 ft 11 in; No. 3 Rhondda 1227 ft 5 in; Hafod 1297 ft 11 in; and Pentre Rider 1422 ft 8 in. The number of that intermediate Rhondda entry is uncertain in the available record.
Bargoed South Pit shaft record: lower interval. The same record gives Gorllwyn Rider at 1550 ft 11 in; Two-Feet-Nine at 1649 ft 2 in; Four-Feet at 1684 ft 7 in; Six-Feet at 1802 ft 6 in; Upper Nine-Feet at 1842 ft 2 in; and Lower Nine-Feet at 1872 ft 2 in. The shaft ended at 1909 ft 8 in. These depths are below one shaft collar, not below each modern park location, and they do not substantiate a blanket 577–650 m source interval for the spoil.
WARWICKSHIRE GROUP
Pennant Sandstone Formation
Hughes Member
Current BGS mapping places the original reference, ST15839919, on sandstone of the Asturian Hughes Member. Regionally this unit contains green-grey lithic sandstone with thinner mudstone, siltstone, seatearth and coal. Its eastern limits are the Cefn Glas Coal below and Mynyddislwyn Coal above. The older Hughes Beds name is historical terminology, not a separate formation.
Bedrock thickness and fossil limits. The modern regional thickness of 45–270 m and the distant 7.6 m Neath reference section do not measure the park exposure. The older regional 500–650 ft thickness likewise does not establish a local tip section. Wider Hughes Beds fish and Anthraconauta records are not a fossil list for the reclaimed spoil.
SOUTH WALES COAL MEASURES GROUP — HISTORICAL WORKED-SEAM CONTEXT
South Wales Middle Coal Measures Formation
This formation contains documented worked coal horizons relevant to the colliery, but is not the proven identity of every park fossil. It spans the Duckmantian–Bolsovian and comprises grey mudstone and siltstone, minor sandstone, seatearth, coal and ironstone deposited in delta and floodplain environments. Its formal boundaries are the Vanderbeckei or Amman Marine Band below and the Cambriense or Upper Cwmgorse Marine Band above.
Lower and Upper Nine-Feet seams. In the Rhymney Valley the Lower Nine-Feet is termed Rhas Las and the Upper Nine-Feet Red Vein; other colliery usages differ. This Red Vein must not be confused with a separate regional Red Vein group near the Six-Feet. Near the Bargoed shafts approximately 30 ft separates the two Nine-Feet leaves. These are underground seam relationships, not layers identifiable across the surface dump.
Bargoed Lower Nine-Feet section. The memoir’s illustrated Bargoed column gives, from top to bottom, coal 6 in, dirt 2 in, coal 2 in, dirt 0.5 in and coal 3 ft. The table warns that sections vary within each colliery. The complete sequence is retained as historical mine evidence, not a measured spoil-bank log.
Lower Nine-Feet roof fauna. The Bargoed underground roof yielded Anthraconaia pumila, cf. Anthracosia nitida and Naiadites cf. productus. Both qualifications and the mine-and-seam provenance matter. The passage supplies no museum accession and does not document these as park-tip finds. Adjacent Oakdale and Penallta assemblages are excluded.
Six-Feet, Yard and Three Quarter. The Six-Feet locally divides into the upper Yard and lower Three Quarter leaves. The Bargoed example’s upper sequence is coal 12 in, dirt 2 in, coal 6 in, dirt 7 in, coal 3 in, dirt 11 in and coal 31 in. After a variable separation, the lower sequence is coal 9 in, dirt 5 in, inferior coal 13 in, dirt 15 in, coal 20 in, dirt 4 in and coal 10 in. These columns illustrate splitting and lateral variation; they cannot be reconstructed by matching loose shale colours in the park.
Underground variations between the Six-Feet, Four-Feet and Two-Feet-Nine. In the Bargoed shafts about 105 ft separates the Six-Feet and Four-Feet, but roughly half a mile farther north-north-east the interval between the main leaves of the Upper Six-Feet and Four-Feet is less than 4 ft. Near and south-east of the shafts the intervening measures exceed 75 ft and include sandstone beds up to 20 ft thick. The main Four-Feet is separated from the Two-Feet-Nine by about 20–35 ft at Bargoed. These are underground variations, not thicknesses observed in the park.
Four-Feet and Two-Feet-Nine. The Four-Feet, often Upper Four-Feet in the Rhymney Valley, has about 36 in of main coal in the cited Bargoed example, with substantial rider splitting. ‘Big Vein’ is specifically an Oakdale usage in this memoir and is not adopted as a verified identity for all Bargoed spoil. Two-Feet-Nine is also variable, with separate South Shaft and western-working columns and changing sandstone, seatearth and mudstone around the coal. Riders are not promoted to formal members.
Two-Feet-Nine: Bargoed South Shaft and south-eastern workings. South-east of the shafts the recorded section includes coal 14 in above approximately 36 in of inferior coal and carbonaceous mudstone. The South Shaft column gives, from top to bottom, coal 12 in, dirt 0.5 in, coal 12 in, dirt 13.5 in, coal 9 in, dirt 4 in and coal 12 in. These are separate mine sections, not a single composite tip succession.
Two-Feet-Nine: western workings. The separate western column gives coal 15 in, dirt 2 in, coal 12 in, dirt 17 in, coal 11 in, an unlabelled 4 in interval, coal 4 in, dirt 2 in and coal 13 in. The lithology of the unlabelled interval is unresolved in the available table, and is not assigned by comparison with the neighbouring column.
Two-Feet-Nine roof and marine-band uncertainty. At the shafts the roof includes approximately 9 ft of sandstone, followed by mainly seatearth 7–9 ft thick and then coal 12 in. The Hafod Heulog band was uncertain and inaccessible at Bargoed in the account; a confirmed marine fauna from another colliery cannot be transferred to it.
Plant impressions in the reclaimed spoil. The original field account records Cordaites, Lepidodendron, Calamites, Stigmaria, Sigillaria and Sphenophyllum, with ironstone nodules and coal. These are field identifications of plant organs, not a species-vouchered inventory or proof of a particular seam. No disposal ledger or specimen-by-specimen mine-to-tip provenance was recovered.
References. Squirrell, H. C., Downing, R. A. and Kelk, B. (1969), Geology of the South Wales Coalfield, Part I: Newport, third edition, Hughes Beds and Rhymney seam accounts, Bargoed seam columns and South Pit appendix; Waters and colleagues (2009), BGS RR/09/01, sections 5.4.2 and 5.5.2.4; BGS Lexicon, Hughes Member; BGS Geology 50k query at the original park reference, dataset version 9.25.
SAFETY
Stay on established open routes and heed closures. Landscaping and tree growth do not prove spoil slopes are stable. Keep away from steep faces, erosion gullies, saturated ground and undercut banks.
Watch for muddy footing, sharp shale, concealed debris and drainage ditches. Do not enter culverts, shafts or old workings. Supervise children and keep clear of cycles and maintenance vehicles on shared routes.
EQUIPMENT
A camera, hand lens, scale and notebook support an observation visit. Wear sturdy footwear and weatherproof clothing. If collecting loose material is expressly permitted, use small rigid padded boxes to protect fragile shale.
Do not assume tool use is allowed. Any agreed splitting requires suitable geological tools, eye protection and a safe position away from public paths. Trowels and prying into banks are inappropriate for the reclaimed park.
CLEANING AND TREATING
Handle carbonaceous films and friable shale gently. Keep parts and counterparts together, avoid soaking or scraping and allow damp pieces to dry gradually. Retain the field label and the distinction between spoil find position and original geological horizon.
Store pyritic material dry and seek specialist advice if new sulphate growth, cracking or powder develops. Avoid casual acid treatments, varnish and routine coating. Unusual fossils are best photographed and referred to a museum before destructive preparation.
IDENTIFY YOUR FINDS
Need help identifying a fossil? Share clear photos, where you found it and its size with the community.
FURTHER READING
BGS: Geology of the South Wales Coalfield, Newport district
BGS: Carboniferous stratigraphical framework
BGS: Hughes Member
Caerphilly Council: tree strategy and Parc Coetir Bargod management context
ACCESS RIGHTS
Bargoed Woodland Park is a council-managed public park. Use signed public entrances and keep to open routes. Public recreational access does not itself establish permission to remove fossils or rock.
Ask the council for the landowner’s permission before collecting or using tools. Follow the exact limits agreed. Do not dig into spoil banks, disturb planted areas or interfere with drainage ditches, and keep service gates and emergency access clear.
It is important to follow our ‘Code of Conduct’ when collecting fossils or visiting any site. Please also read our ‘Terms and Conditions‘
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