High Sedling Mine

Overview

High Sedling appears in the 1930 List of Mines at Cowshill in upper Weardale, worked for fluorspar by Hinchcliffe Brothers and Company of Sheffield with six men underground and one at the surface — and marked, in the same return, as abandoned. It lies on the Sedling ground, where the vein of that name is among the richest in Weardale, and it is the fluorspar era rather than the lead era that it belongs to.

History

The 1930 List of Mines under the Metalliferous Mines Act enters High Sedling at Cowsgill — Cowshill — owned by Hinchcliffe Brothers and Co., Ltd. of Town Hall Chambers, Fargate, Sheffield, with six men underground and one at the surface, working fluorspar, and the bracketed remark '(Abandoned)'. That is the whole of the working record found for it.

The context is the second life of Weardale mining. County Durham was one of the world's first commercial sources of fluorspar, when industrial demand grew in the 1880s for what lead miners had spent a century throwing on the tip; through the 20th century the dale's old lead ground was reworked for it. A Sheffield firm taking a small sett at Cowshill in the 1920s fits that pattern exactly — fluorspar went to the steel industry as a flux, and Sheffield is where the steel was. The neighbouring Sedling Mine, on the same vein, had been worked for lead by the Beaumont Company from 1818 and was reworked for fluorspar by the Weardale Lead Company until 1948.

Geology

Cowshill sits at the head of Weardale on the Burtreeford Disturbance, the north-south structure that displaces the strata of the dale. The Sedling vein runs roughly east-south-east to west-north-west from its eastern side and is among the richest of Weardale's lead-bearing veins; the Durham geodiversity audit lists Sedling Mine at Cowshill as a mineral-vein site running from NY 859 409 to NY 868 407, nearly a kilometre along the vein. The county's veins mostly occupy normal faults of small throw, and show crude bands of relatively pure minerals — fluorspar, barytes and witherite among them — parallel to the vein walls; it was those non-metallic minerals, long discarded, that were mined here in the 20th century.

Geological setting: Veins and Lodes (historical documentary reference)

Workings

Unknown. The record gives no more than the return's seven people, six of them underground. Nothing on record describes the levels or the extent of the sett.

Closure

The 1930 return records the mine as already abandoned. Nothing on record establishes when Hinchcliffe Brothers took the sett or when they gave it up.

What remains

Unknown. The Sedling ground at Cowshill carries extensive remains and is listed in the county's geodiversity audit as a mineral-vein site.

Unknown. Nothing on record distinguishes what survives at High Sedling from the wider Sedling remains at Cowshill.

Related mines

• Sedling Rake Mine — Both are workings on the Sedling ground at Cowshill and both were returned in the statutory lists under their own names — Sedling Rake worked by the Beaumont Company for lead from 1818 and reworked for fluorspar by the Weardale Lead Company to 1948, High Sedling held in 1930 by Hinchcliffe Brothers of Sheffield for fluorspar. Whether they worked the same ground at different levels is not established by anything read here.

What's uncertain

Points where sources disagree or the record could not be settled; both accounts are kept. All open questions in the archive.

• The BGS mine-plans catalogue holds a BGS plan titled 'High Sedling Mine' (catalogue MP18748, 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) ³

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• The 1930 List of Mines records High Sedling at Cowsgill, owned by Hinchcliffe Brothers and Co., Ltd. of Town Hall Chambers, Fargate, Sheffield, with six men underground and one at the surface, working fluorspar, and the remark '(Abandoned)'. ¹
• The Durham geodiversity audit lists Sedling Mine, Cowshill, as a mineral-vein site extending from NY 859 409 to NY 868 407. ²
• County Durham was one of the world's first commercial sources of fluorspar, when industrial demand developed in the 1880s for what had been a waste product of lead mining; the county's veins carry crude bands of fluorspar, barytes and witherite parallel to the vein walls. ²
• The BGS mine-plans catalogue holds a BGS plan titled 'High Sedling Mine' (catalogue MP18748, 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) ³

Sources

1. (primary) 1930 List of Mines under the Metalliferous Mines Act: Durham — Durham Mining Museum
2. (primary) Mineral veins and flats — County Durham geodiversity audit — B. Young, British Geological Survey, in the Durham Geodiversity Audit (GeoGuide)
3. (primary) BGS / Mining Remediation Authority mine plans: HIGH SEDLING MINE — British Geological Survey / Mining Remediation Authority

Record created: 5 September 2026 · Last researched: 6 September 2026