Soudley Valley’s geological trail crosses a varied part of the Forest of Dean. This guide centres on the plant-bearing coal spoil associated with Eastern United Colliery, near Ruspidge and Staple Edge, while keeping the trail’s older limestone and sandstone exposures distinct. Confirm access and collecting permission before entering the spoil.
FIND FREQUENCY: ♦♦ – The 2010 inspection recorded roots, Calamites stems and occasional foliage in shale; present yields are uncertain.
CHILDREN – The uphill approach and former mining ground require close supervision; keep away from faces, unstable spoil and mine openings.
ACCESS – An uphill woodland approach from Ruspidge; use the currently permitted route and confirm access to the specific spoil area.
TYPE – Reworked colliery spoil. Separate Devonian and early Carboniferous exposures occur on the wider geological trail.
DIRECTIONS
♦ From Cinderford, take Ruspidge Road south through Ruspidge. Beyond the village the road bends left; the historical approach to the spoil begins from the right-hand side of this road near Staple Edge.
♦ The approach follows a track uphill towards the former colliery spoil area, with a return bend higher on the hillside. Confirm the present signed route and agreed entrance before setting out: forestry work, redevelopment and vegetation can alter the old landmarks.
♦ Keep road junctions, gates and working tracks clear, and use only a lawful parking place. The small roadside pull-ins described at the 2010 visit should not be treated as reserved parking or permission to enter the land.
♦ Location reference: 51.79805°N, 2.50955°W. This is an approach reference for the guide locality, not a surveyed centre of the spoil heap or a parking entitlement.
♦ For travel via Soudley village, check the parish council’s Upper Soudley Bridge notice. Upper Soudley Bridge repairs were scheduled for 21 September–23 October 2026. Follow the signed diversion; this notice concerns that approach and does not establish closure of the whole trail.
FOSSIL HUNTING
The collecting interest at the former Eastern United spoil is plant-bearing shale discarded during coal mining. The 2010 inspection recorded stem impressions identified as Calamites, fossil roots and occasional fern-like foliage. These are dated field observations rather than a prediction of what will be exposed on a new visit. The waste has been tipped and disturbed, so a specimen’s position on a mound does not reveal the bed or seam from which it was mined.
On an authorised observational visit, concentrate on already exposed surfaces of stable, loose shale visible from the permitted route. Fine-grained slabs are more useful for recognising flattened leaves and stems than the coarse rubble around them. Examine them in oblique light, using a hand lens for vein traces or repeated surface detail, and photograph the whole rock before its individual features. Leave embedded blocks and vegetation undisturbed. Do not dig into the mounds or seek fresh material by undercutting them.
Calamites is the name commonly applied to stem remains of extinct horsetail relatives. Longitudinal ribs and joints crossing the stem are useful features to record, but a grooved fragment is not enough to establish a species. Photograph the end and both sides when these are naturally visible. The local account does not supply a checked species list, and its mention of roots does not identify every root-like object as Stigmaria. Keep uncertain material labelled as a possible stem or root, rather than adding a more specific name without diagnostic evidence.
Foliage may occur as isolated leaflets, branching impressions or several overlapping fragments on one bedding surface. The useful details are how the leaflets attach, whether a central vein can be followed, and whether the apparent pattern continues across the slab. Random fractures and stains may mimic parts of a plant, so an overall photograph matters as much as a close-up. If removal is permitted, keep naturally separated counterparts together and retain enough matrix to show these relationships. Forceful splitting can detach the thin fossil-bearing surface.
The wider trail has a different fossil story. Crinoidal limestone at Blue Rock and the historical marine fauna of Shakemantle belong to separate early Carboniferous exposures, not to this coal-spoil assemblage. Their shells and corals should not be added to a list of expected spoil finds. Likewise, a specimen from another Forest of Dean mine needs its own locality label. Record “Eastern United spoil” only when the actual find point supports that attribution, and keep a photograph showing its context. Particularly good or unusual material is best left unprepared for identification.
A chronological record of fossil research, mining geology and site-history milestones associated with Soudley Valley.
1916 – Eastern United’s disturbed strata studied
C. J. Morgan described the unusual strata encountered in the Eastern United workings. The investigation helped explain the effects of the Staple-edge Monocline, including the exploratory heading through steep beds towards the Yorkley coal.
1942 – Detailed valley sections documented
The six-bed section north of Staple-edge Halt and the dolomite succession at Shakemantle were recorded at their separate quarries. These measurements established a useful geological framework without turning the distinct exposures into one continuous section.
30 January 1959 – Eastern United Colliery closes
The colliery’s closure marked a major change in the valley’s coal-mining landscape. Its surviving spoil records the handling of coal-bearing rocks, although the closure date does not identify the final deposition date of each heap.
1961 – Marine quarry sections and fossils documented
Further detailed work recorded Shakemantle’s measured dolomite succession and historical marine fauna, together with fossils from the small Whitehead limestone quarry nearby. These observations concern the older marine rocks, distinct from the plant-bearing coal spoil.
November 1977–March 1978 – Geological trails rehabilitated
Eleven major geological localities were cleared and restored as part of work on two Soudley trails. The project made the area’s separate exposures more useful for teaching and interpretation; its historical footprint does not define present collecting rights.
GEOLOGY
The plant-bearing spoil near Ruspidge is associated with Eastern United Colliery and its workings in the Coleford High Delf coal. Mining brought the surrounding shale and sandstone to the surface along with the coal, leaving a reworked deposit rather than a natural sequence of exposed beds. The geology of a loose specimen therefore has two parts: the late Carboniferous rock in which it formed, and the much later mining and tipping that placed it on the hillside.
In modern BGS terminology the relevant source rocks belong to the Coleford Member, within the Pennant Sandstone Formation and Warwickshire Group, of Asturian age. The High Delf seam lies inside that member. River channels deposited the substantial sandstone bodies, with finer mudstone and plant-rich deposits representing quieter environments between them. Coal seams mark episodes of accumulated vegetation. This explains why the spoil includes different rock types and why fine shale can preserve plant impressions, without requiring every fragment to have come from the roof of one seam.
The sandstone cutting behind the spoil was noted at the 2010 inspection, when no fossils were reported there. That observation is not a rule that Pennant sandstone everywhere is fossil-free. Nor has this cutting been securely matched to the old quarry immediately north of Staple-edge Halt described in 1942. That separate quarry displayed six beds, including a thin coaly grit at the Whittington horizon beneath a thick cross-bedded sandstone. Reworked coal fragments in the sand illustrate erosion and transport within the original river system, long before modern mining mixed the spoil.
Underground, the Staple-edge Monocline complicated the Eastern United workings. An exploratory heading recorded an 18-inch Yorkley seam and intervening strata that were locally vertical. This evidence explains why a simple horizontal model is inappropriate in parts of the mine; it does not mean that every outcrop or trail stop has the same dip. Mine sections, quarry logs and tipped shale must be interpreted at their own scales.
The wider Soudley trail provides a separate view of the Forest of Dean’s older rocks. Devonian sandstone and conglomerate, transitional Tintern sandstone, early Carboniferous marine limestone and dolomite, and younger sandstone occur at distinct exposures with gaps between them. Blue Rock, Shakemantle and the Whitehead limestone records belong to this broader valley story. Marine fossils and crinoidal bands contrast with the terrestrial plants of the coal measures. The expanded account explains these separate stops and historical names without turning them into one continuous section through the spoil or claiming that the entire Carboniferous succession is visible on the walk.
The Eastern United coal-spoil framework, separate Staple-edge quarry section and older rocks of the Soudley trail.
The guide’s coal-spoil stop is distinct from the old Staple-edge quarry and the older sedimentary rocks exposed elsewhere on the Soudley trail. The sections below keep these settings separate. Mine and quarry measurements are historical observations, not assurances that the same faces remain exposed or accessible today.
WARWICKSHIRE GROUP
The late Carboniferous coal-bearing source rocks belong to the Warwickshire Group. The spoil itself is a reworked mining deposit, not an additional formation or an intact section through the group.
Pennant Sandstone Formation
The Pennant Sandstone Formation provides the parent framework for the sandstones, mudstones and coal seams discussed here. Historical use of “Pennant Group” is not identical to the modern formation boundary.
Coleford Member
The Coleford Member is Asturian and dominated by substantial Pennant-type lithic sandstone bodies, with subordinate grey and green mudstone, ironstone concretions and coal. Its modern base is the lowest Pennant-type sandstone, beneath the Coleford High Delf; its upper boundary is the base of the Brazilly Coal. The member’s river-channel interpretation and regional boundaries do not supply a bed assignment for an unprovenanced loose specimen.
Eastern United spoil and rear sandstone cutting
The spoil is historically associated with Coleford High Delf mining and contains the field-recorded Calamites stems, unidentified roots and occasional foliage. These are not a measured roof-shale fauna or a species-level voucher collection. A sandstone cutting was reported behind the heap, but its correlation with the old quarry north of Staple-edge Halt is not established.
Old quarry immediately north of Staple-edge Halt
Trotter’s 1942 section lies between the High Delf and Yorkley seams. It is reproduced youngest to oldest with the original bed numbers, from 6 down to 1. It belongs to this separate in-situ quarry, not to the reworked spoil.
Staple-edge quarry, Bed 6.
Massive gritty cross-bedded sandstone (historical false-bedded); thickness 45 ft.
Staple-edge quarry, Bed 5.
Coarse grit with 3 and locally 4 coal layers; thickness 2.5 ft; individual coal layers up to 2 in; where disrupted, coal fragments incorporated in overlying sandstone; Whittington Seam horizon.
Staple-edge quarry, Bed 4.
Grit with mudstone pellets; thickness 2 ft.
Staple-edge quarry, Bed 3.
Flaggy sandstone with shale partings; thickness 6 ft.
Staple-edge quarry, Bed 2.
Sandy blue shale; thickness up to 1 ft.
Staple-edge quarry, Bed 1.
Massive grit; thickness 1 ft.
The three, locally four, coal layers in Bed 5 reach 2 in individually. Where disrupted, their coal fragments occur in the sandstone above. The 2½ ft thickness describes the whole coaly-grit interval; it is not the thickness of each coal layer.
Eastern United and the Staple-edge Monocline
The underground exploratory heading described after Morgan’s 1916 work proved the Yorkley seam at 18 in, with locally vertical intervening beds between it and the High Delf. The structural cross-section illustrates that disturbed geometry; it is not a complete bed-by-bed journal. No general vertical dip is assigned to the entire trail.
Shared Main Basin coal context. The 1942 memoir discussed Eastern United together with Cannop and Arthur and Edward collieries. In that shared account, the High Delf averaged 4–4½ ft and locally reached 7 ft. Roofs were mostly sandstone, with the Arthur and Edward shale roof distinguished separately; locally up to 18 in of carbonaceous shale or shaly coal occurred below rock roofs, and marden replaced part of the lower coal. These are multi-colliery observations, not a measured Eastern United-only seam or proven spoil provenance.
Separate trail exposures: younger rocks and fills
A 2011 account of the Perseverance Road Cutting described a patch of sand within Carboniferous rock as Triassic fill. This is a qualified field-club interpretation of a later fissure or channel deposit, not an additional bed in the coal-spoil succession.
PEMBROKE LIMESTONE GROUP
The marine limestone and associated sandstone units below form a separate early Carboniferous framework. Historic names remain useful for recognising the quarry literature, but their modern equivalents are not additional layers to be stacked beside them. The trail exposures are discontinuous.
Cromhall Sandstone Formation
Shakemantle sand quarries: historical Drybrook Sandstone
The 2011 trail account describes the sand quarries as Drybrook Sandstone. Modern regional nomenclature relates the Lower and Upper Drybrook units to the Cromhall Sandstone Formation. An exact lower/upper tongue assignment, local bed log and fossil list are not established for these particular quarries; a measured section from Tidenham is not applied here.
Separate Drybrook railway cutting south-east of Staple-edge Halt. The older memoir recorded about 140 ft of the upper historical Drybrook Sandstone in a separate cutting near Ruspidge. It comprised white ganisters, white or pink rounded-grain quartzitic sandstones and occasional conglomerate. The historical exposure belongs within the cautiously stated Cromhall framework, but its thickness is not transferred to the Shakemantle sand quarries.
A different historical angular contact at Ruspidge. In the railway cutting at Ruspidge, two feet of grit and fine conglomerate dipped 20° west-north-west above historical Drybrook Sandstone dipping 50° west. The memoir placed this observation in its Trenchard account. The source does not establish a precise current formation assignment; this contact is distinct from the Brownstones and quartz-conglomerate unconformity farther south on the trail, and from the Staple-edge quarry or any spoil sequence.
Llanelly Formation
Historical Whitehead Limestone: small quarry SO 652 114
The 1961 account records dolomitic Whitehead Limestone in a small quarry about 150 yd south-west of Shakemantle. Whitehead is placed in the Llanelly Formation framework. The locality reference belongs to that quarry and is not silently moved to the differently gridded Perseverance Road Cutting. No local thickness for a basal “Lid” or “Lidstone” bed is established.
| Entry | Whitehead quarry: historical identification |
|---|---|
| 1 | Spirorbis sp. |
| 2 | cf. Composita ficoidea (Vaughan) |
| 3 | Grammatodon walciodorensis (de Koninck) |
| 4 | Paraparchites subrectus (Portlock) |
| 5 | Glyptopleura cf. costata (M’Coy) |
These five names are the historical determinations for the small Whitehead quarry. Their qualifiers are preserved; they are neither a modern taxonomic revision nor a list of expected Eastern United spoil fossils.
The earlier Whitehead quarry account. The 1942 memoir located a small Whitehead quarry 500 yd south-east of Staple-edge Halt. It listed Grammatodon sp. as well as G. walciodorensis, whereas the 1961 list omitted the indeterminate entry. Its Glyptopleura cf. costeta spelling differs from the later cf. costata. These differences concern dated records and nomenclature, rather than a second proven species or a silently fixed match between differently located quarries.
Gully Oolite Formation
Historical Crease Limestone at Shakemantle
The upper part of the measured Shakemantle exposure comprised 25 ft of coarse granular dolomite with crinoidal bands, assigned historically to the Crease Limestone. The modern regional framework uses Gully Oolite Formation for the Crease unit. This 25 ft is the logged exposure, not the formation’s complete regional thickness. The basal rocks of that quarry are described separately below.
BLACK ROCK LIMESTONE SUBGROUP
Historical Lower Dolomite at Shakemantle Quarry, SO 653 113
The Lower Dolomite of the older memoirs is represented in the modern Black Rock Limestone Subgroup framework. The quarry log records a succession dipping 50–60° west. Its dolomitised rocks range from dense fine material to coarser crinoidal bands. Fossils were listed for the Lower Dolomite collectively, without allocation to every measured bed.
Shakemantle’s historical measured section
Shown top to bottom here, from the Crease Limestone into the older Lower Dolomite. The interval labels identify positions in this source account. The basal 12 ft were not exposed, and the shale parting has no stated thickness.
Shakemantle section, interval 1.
Crease Limestone:coarsely granular dolomite, crinoidal bands; thickness 25 ft exposed.
Shakemantle section, interval 2.
Grey-white/pink medium–coarse dolomite, several strongly crinoidal bands; thickness 15 ft.
Shakemantle section, interval 3.
Fine-grained dolomite, massive posts; thickness about 135 ft.
Shakemantle section, interval 4.
Purplish shale parting; thickness not stated.
Shakemantle section, interval 5.
Dense compact grey-blue dolomite, beds 1–2 ft; thickness 17 ft.
Shakemantle section, interval 6.
Dolomitic mudstone; thickness 1 ft.
Shakemantle section, interval 7.
Basal Lower Dolomite not exposed; thickness 12 ft absent from observed section.
The 25 ft Crease interval is the Gully Oolite-equivalent unit described above; the remaining exposed rows are the historical Lower Dolomite. The unexposed basal 12 ft are not counted as a directly visible rock thickness, and no artificial total is created by treating the unmeasured shale parting as zero.
Shakemantle Lower Dolomite fauna
The 1961 identifications below include corals, brachiopods and molluscs. They retain the historical names, uncertainties and the gamma qualifier. They have not been reassigned to modern accepted species, to individual numbered beds, or to the coal spoil.
Differences in the 1942 Shakemantle determinations. The earlier list included two separately qualified Daviesiella? entries. Its footnoted first form was compared historically with Chonetes cf. comoides, with a bifurcating median septum and a substantial ventral cardinal area; the second tended towards D. carinata. It also recorded Schellwienella aspis mut. radialiformis “and an allied form”, and used Protoschizodus cf. axiniformis where the later account used Schizodus. These are differences between historical identifications, not newly accepted taxa or additional measured beds. The footnote’s Blake’s Wood specimen does not belong to Shakemantle.
| Entry | Shakemantle: historical identification |
|---|---|
| 1 | ? Caninia cornucopiae Michelin |
| 2 | Fasciculophyllum [Zaphrentis] omaliusi (Edwards and Haime) |
| 3 | “Zaphrentis” spp., including “Z.” konincki Edwards and Haime |
| 4 | Chonetes (Megachonetes) aff. papilionaceus Phillips |
| 5 | Daviesiella? [a form tending towards D. carinata] |
| 6 | Schellwienella aspis Smyth mut. radialiformis Demanet |
| 7 | Spirifer cf. tornacensis de Koninck |
| 8 | Tylothyris laminosa mut. γ North |
| 9 | Tylothyris laminosa, transient towards T. subconica (Martin), as interpreted by North |
| 10 | cf. Productus (Dictyoclostus) teres Muir-Wood |
| 11 | Productus (Linoproductus) sp. |
| 12 | Schizodus cf. axiniformis (Portlock) |
| 13 | Bellerophon tangentialis Phillips |
| 14 | Naticopsis sp. |
AVON GROUP
Lower and Upper Blue Rock quarries
The early Carboniferous limestone-and-shale succession historically called the Lower Limestone Shales belongs to the Avon Group framework. The Lower and Upper Blue Rock exposures have been described separately at SO 6533 1074 and SO 6532 1086. A 2013 visit noted a crinoidal slab at Blue Rock, without a species identification. The measured Wilderness Quarry section at Mitcheldean belongs to another locality and is not used as a Blue Rock log.
Blue Rock in the 1942 quarry description. Thin flaggy dolomites and limestones with calcareous shale were assigned historically to the lower part of the Lower Limestone Shales in a quarry 700 yd W 37° N of Upper Soudley Halt. This unmeasured exposure is distinct from the later crinoidal-slab observation. The same account placed Lower Dolomite in a railway cutting 100 yd west and another quarry 300 yd north-north-west; those separate exposures are not extra layers in a Blue Rock measured log.
BRECON BEACONS GROUP
PORTISHEAD SUBGROUP
Tintern Sandstone Formation
Tintern sandstone in the route succession
The upper Old Red Sandstone framework places the Tintern Sandstone in the Portishead Subgroup. Its regional age extends from the Famennian into the Tournaisian, across the Devonian–Carboniferous transition. That broad age and the valley-route occurrence do not establish a bed-specific fossil assemblage or a complete measurable section at the spoil stop.
Huntsham Hill Conglomerate Formation: regional correlation
Quartz conglomerate in the railway cutting
The trail account describes quartz conglomerate above an unconformity on the Brownstones at the cutting near SO 6541 1045. Modern regional nomenclature identifies the Forest of Dean’s upper Old Red Sandstone conglomerate as the Huntsham Hill Conglomerate Formation within the Portishead Subgroup. This is a provisional correlation for the precise cutting, rather than a new large-scale mapping determination; no regional formation thickness is substituted for the local exposure.
DAUGLEDDAU GROUP
COSHESTON SUBGROUP
Brownstones Formation
Older Devonian rocks beneath the unconformity
The railway cutting near SO 6541 1045 exposes the sandstone-and-mudstone Brownstones succession beneath the younger quartz conglomerate. The modern Old Red Sandstone framework places the Brownstones in the Cosheston Subgroup of the Daugleddau Group. This relationship records a break in the succession; it is not part of the late Carboniferous coal-bearing sequence represented by the spoil.
Plant fossils illustrated from Mine Train Quarry at Bixslade, Stigmaria from Hopewell mine and the regional Lydbrook roof-shale flora belong to different localities. The other-mine megaspore and bivalve lists likewise do not establish new fossils at Eastern United. These distinctions prevent neighbouring discoveries from becoming misleading collecting expectations here.
References
BGS Lexicon, Coleford Member, Tintern Sandstone and Gully Oolite entries.
Waters and colleagues (2009), Carboniferous lithostratigraphical framework, RR/09/01; and BGS (2015), the Old Red Sandstone lithostratigraphical framework.
F. M. Trotter with W. C. C. Rose (1942), Geology of the Forest of Dean coal and iron-ore field, especially pp. 16 and 38–40.
F. B. A. Welch and F. M. Trotter (1961), Geology of the country around Monmouth and Chepstow, especially pp. 66–67.
Malvern U3A Forest of Dean field visit (2011); Gloucestershire Naturalists’ Society Soudley geology walk (2013). These provide dated observations of the separate trail stops.
SAFETY
Use the currently permitted track and obey closures, diversion signs and forestry instructions. The approach is uphill and can be muddy, with roots, uneven steps and loose stone. Allow enough time and energy for the return, and turn back if a safe route is unclear.
Keep away from quarry edges, faces, overhangs, unstable spoil and all mine openings or concealed hollows. Do not enter adits, shafts or fenced workings, and do not dig into or climb spoil mounds. Rockfall and poor footing are relevant hazards even where the main track appears easy.
Children require close supervision. Avoid disturbing ant nests and other wildlife; wood ants were noted at the 2010 inspection. Keep dogs controlled around working areas and wildlife. For a wider trail walk, assess each separate quarry or cutting on arrival rather than assuming conditions are the same as at the spoil.
Upper Soudley Bridge works were scheduled for 21 September–23 October 2026. Check the latest road notices before travelling through the village and follow the signed diversion. The bridge notice does not establish the status of every woodland path.
EQUIPMENT
Take sturdy boots with good grip, a map, a charged phone, water, a hand lens and a photographic scale. A camera record is especially useful here because the spoil, rear cutting and separate marine exposures must not be confused.
Where removal has been expressly permitted, carry soft wrapping and a rigid box for shale slabs and counterparts. Picks, spades and face hammering are not recommended: an observational visit should leave the tip, quarry faces and trail infrastructure undisturbed.
CLEANING AND TREATING
Label an authorised specimen with the exact find point and whether it came from spoil or an in-situ exposure. Photograph it before preparation. Support fragile shale slabs, retain counterparts, and let damp material dry slowly at room temperature. Start only with a very soft dry brush and stop if the fossil film or matrix lifts.
Do not routinely soak, coat or force shale apart. Repeated wetting can damage weathered material, and a fresh split can destroy a plant impression. Avoid household acids, bleach and varnish. Leave potentially important or very fragile specimens unprepared for specialist advice.
The separate marine limestone and dolomite exposures require different interpretation and preparation. Fossils may be altered or preserved as casts, with little separation between fossil and matrix. Do not apply a plant-shale splitting method to them or force hard matrix from a fossil surface. Any removal still needs the relevant land manager’s consent.
IDENTIFY YOUR FINDS
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FURTHER READING
Deposits: Geology and terrestrial life of the Carboniferous (general background)
BGS Lexicon: Coleford Member
BGS: Geological plants, including horsetails and ferns
Geological Survey: Forest of Dean coal and iron-ore field (1942)
Geological Survey: Monmouth and Chepstow geology (1961)
Forest of Dean Local History Society: Eastern United Colliery
ACCESS RIGHTS
Confirm the current route and the land manager’s permission for the precise spoil area before entering it, and agree separately whether loose material may be removed. The history of a geological trail does not itself grant collecting rights at every stop.
The exact present ownership and collecting terms for this heap have not been established. Historical work on Forestry Commission land and current heritage activity in the surrounding forest should not be treated as proof of the heap’s present management boundary. Respect all notices, fences, working areas and individual quarry restrictions; if consent cannot be established, observe only from a lawful public route.
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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