Slack, Mount Pleasant and Barmasters Grove Lead Mines

Overview

When Slack Mine's new owner probed its depths in 1882, he found water waiting at 222 feet -- a discovery that triggered an ambitious sough extension abandoned for want of money, on a Bonsall Moor mining ground already old by the time it was first recorded in 1541.

History

On Bonsall Moor, between Bonsall Lane and Tower Lane, an area of mining containing Nether Slack, Upper Slack, Scorah Slack, Barmasters Grove and Mount Pleasant lies just north of the Great Bonsall Fault, its lead veins running through gently folded limestone beneath the Matlock Lower Lava. Ore accounts from 1541 give the earliest documented record of mining on Bonsall Moor, though most of the surviving surface remains date from more intensive 18th- and 19th-century working; a Barmasters Record of 1744 already describes the ground as 'old' when Scorah Founder registered a claim there. The area later played a part in the development of early geological theory, featuring in the arguments of Pilkington and Whitehurst concerning the genesis of lava and its relation to surrounding limestones. In 1881, Slack Mine and its adjacent workings were bought by Edward Wass, who the following year had his agent Jonathon Stevenson examine the mine's New Shaft -- an inspection that found water waiting at a depth of 222 feet (67.6 metres). In response, it was proposed to extend the existing 18th-century Dalefield sough some 800 yards (732 metres) to reach the mine; the work was begun but never completed, abandoned for lack of funds. Surviving remains include several almost parallel veins and scrins running roughly north to south, marked by hillocks interspersed with shafts and open cuts. At the northern end, near Nether Slack, a shaft documented in the late 18th century as 50 fathoms deep has now partly collapsed, standing beside a retaining wall and coe close to Bonsall Lane, near an ore-processing area with a water channel and buddling ground. Towards the south, near Scorah Slack, a large shaft sits within a substantial coe with retaining walls; similar remains mark Mount Pleasant and Barmasters Grove further east, where at least ten open shafts are scattered along lines of hillocks, hollows and deep open pit-holes. As is typical of Derbyshire lead-mining custom, the individual mines here are not marked by concentrated centres of activity but by stretches of vein worked by different miners or small groups, governed throughout by the Barmote Courts. Scheduled as a nationally important monument in January 2000, the site is valued for its particularly early origins and for the range of mining and processing features that together allow its chronological development to be reconstructed.

Geology

Several almost parallel lead-bearing veins and scrins on Bonsall Moor, running through folded limestone beneath the Matlock Lower Lava, just north of the Great Bonsall Fault.

Workings

Nether Slack, Upper Slack and Scorah Slack shafts and coes on two parallel veins, an ore-processing area with a water channel and buddling ground, and at least ten further open shafts at Mount Pleasant and Barmasters Grove.

Closure

No reliable closure date has yet been located; an 1882 sough extension aimed at draining the mine deeper was begun but abandoned unfinished for lack of funds.

What remains

Scheduled as a nationally important monument since January 2000; site monitoring found it not under threat.

Hillocks, shafts, open cuts, coes with retaining walls, a water channel and buddling area, and at least ten further open shafts across Mount Pleasant and Barmasters Grove survive.

Nearby mines

• Beans and Bacon Mine — 0.4 km SW
• Gorseydale Lead Mines — 0.6 km W
• Mount Pleasant Lead Mines — 1.4 km N
• Northern Dale Lead Mines — 1.4 km NE
• Winster Pitts and Drummer's Venture — 1.4 km NW

Straight-line distance, within 15 km. Show on the map.

Recorded claims

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

• Ore accounts dating from 1541 provide the earliest record of mining on Bonsall Moor; in 1881 Slack Mine and the adjacent mines were bought by Edward Wass who in the following year had his agent, Jonathon Stevenson, examine the New Shaft at the mine, which revealed water at a depth of 222 feet (67.6m), leading to a proposed but never-completed 800-yard extension of the Dalefield sough. ¹
• The area contains a number of mines including Nether Slack, Upper Slack, Barmaster Grove, Scorah and Old Harry, mentioned in Barmasters Records of 1744 when Scorah Founder describes it as 'old'; the area also featured in the development of early arguments of Pilkington and Whitehurst concerning the genesis of lava and its relation to surrounding limestones. ²
• At the northern end of the monument, in the area of Nether Slack, is a shaft documented in the late 18th century as being 50 fathoms deep, now partly collapsed, sitting adjacent to a retaining wall and a coe close to Bonsall Lane, near an ore processing area including a water channel and buddling area. ¹

Photographs & further reading

Sources

1. (primary) Slack, Mount Pleasant and Barmasters Grove lead mines 390m south east of Blakelow Farm, Bonsall, Derbyshire — AncientMonuments.uk (mirroring the Historic England scheduling record)
2. (primary) Derbyshire HER: Slack, Mount Pleasant and Barmasters Grove mines and rake, 390m south east of Blakelow Farm, Bonsall (MDR8634) — Derbyshire Historic Environment Record

Record created: 17 September 2026 · Last researched: 17 September 2026