Open questions: Wrexham

Where sources disagree, MineArchive keeps both accounts rather than picking one; where a fact could not be settled, the record says so. 14 such claims on 10 records. All regions.

Broughton Colliery

• Welsh Coal Mines states that Broughton Hall, the old colliery, closed in 1978 — a date that would make a pit sunk in 1835 one of the longest-worked in the Denbighshire coalfield, and which nothing else on record confirms. (uncertain)

Brymbo Colliery

• The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Brymbo' (catalogue 6286, Drowsall, Powell & Queen (Wall & Bench), dated 1914); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Brynmally Colliery

• The colliery was probably sunk in the late 1830s or early 1840s and was purchased by Thomas Clayton and Company in 1849. It also went by the name Pwll y Pendwll. (uncertain)

Cambrian Quarry

• Major working began in 1854 at Martin's quarry, formerly Chwarel Uchaf. (uncertain)

Gatewen Colliery

• The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Gatewen' (catalogue 8458, Smith, Powell, dated 1924); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Llay Main Colliery

• At sinking the colliery was described as the deepest pit in Europe, at a depth of about 730 metres. (disputed)

Minera Lead Mines

• Roman-period working of the field is often claimed but has no supporting archaeological evidence. (disputed)
• One observational source dates the effective abandonment to around 1909, ahead of the commonly cited 1914 closure. (disputed)
• Meadow Shaft and Taylors Shaft each reached roughly 300-400m (c. 400 yards) deep. (uncertain)

Vauxhall Colliery

• The two sources agree on 1896 — 361 underground and 64 on the surface, 425 in all — but not on 1923: Welsh Coal Mines gives 535 underground and 111 on the surface, 646 in all, against the Durham Mining Museum's 578. (disputed)
• The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Vauxhall' (catalogue 10608, Top Yard (Smith'S), Seven Feet (Two Yard) ,Quaker (Brassey), Main, Brassey (Crown), Upper Yard (Probably Stone) ,Middle Stone, Lower Yard (Ruabon Yard), Wall And Bench, dated 1931); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Westminster Colliery

• The BGS mine-plans catalogue holds a Mining Remediation Authority abandonment plan titled 'Westminster' (catalogue NW1398, Brassey, undated in the catalogue); the catalogue gives no location and the plan's details do not clearly tie it to this working, so it may belong to another of the same name. (uncertain)

Wynne Quarry

• The quarry and mine closed in 1920. (disputed)
• The quarry closed in 1905, reopened briefly in 1910 and 1923, and closed finally in 1928. (disputed)