Duntanlich Mine

Overview

The UK's only currently working baryte mine, built between 2016 and 2020 to keep the country self-sufficient in the mineral used to weight North Sea drilling fluids once the nearby Foss Mine, worked since the 1980s, finally ran down. Its 2016 planning approval came only after two earlier attempts, in 1992 and 1996, were turned down over the impact on the Loch Tummel and Queen's View beauty spot.

History

Duntanlich was developed by M-I SWACO, the Schlumberger oilfield-services subsidiary that had operated the nearby Foss Mine (see separate entry) since the 1980s, once it became clear that Foss's baryte reserves — a mineral used almost entirely as a weighting agent in oil and gas drilling fluids — were running down. A mine here had first been proposed some 25 years earlier: an initial application was rejected by Perth and Kinross councillors in 1992, and a second attempt was turned down on appeal at the Court of Session in 1996, largely on environmental grounds relating to the site's proximity to Loch Tummel and the well-known viewpoint at Queen's View. A third application, submitted in early 2015, was finally approved by Perth and Kinross Council's development management committee on 14 September 2016 by an 8-3 vote, after objections centred not on the mine itself but on the proposed haulage road, which residents at Logierait feared would blight their village; over 130 people signed a petition against the route within a week of it being made public, and alternative approaches — including a direct link to the A9 near Pitlochry — were argued for unsuccessfully by objectors. Construction of the mine's surface infrastructure — access roads totalling around 15km, a processing building, weighbridge, workshop and welfare facilities — was completed in December 2020 at a cost of some £9.7 million, on a site covering about 183.5ha, and the mine has been in production since 2020. Foss was run down over the following months once Duntanlich reserves came on stream, and closed for good in 2021. At planned production rates of up to 120,000 tonnes of baryte a year, Duntanlich's identified reserve of more than 7.5 million tonnes is projected to be sufficient to keep the UK self-sufficient in the mineral for over 50 years.

Geology

Duntanlich lies within the same Dalradian baryte belt as the neighbouring Foss deposit, hosted in schist and quartzite of broadly similar age and structural setting, though as a physically separate orebody roughly 10km to the north-east. As at Foss, the baryte occurs as a syn-sedimentary, exhalative hydrothermal deposit laid down within a late Precambrian back-arc basin — the same fundamentally sediment-hosted, rather than granite-vein-hosted, style of mineralisation that makes the wider Aberfeldy barytes belt distinctive among British ore deposits; mineral records for the site also note associated galena.

Workings

An underground mine reached by drift rather than a mineshaft, worked by drilling and blasting; ore is hauled to a surface processing building for grading before onward transport for further processing. Access is via a purpose-built haul road network completed in 2020, connecting the mine to the wider road network without routing heavy traffic directly through Logierait, following extended negotiation over the route during planning.

What remains

Duntanlich remains an active working mine, operated by M-I SWACO as the United Kingdom's sole current source of domestically mined baryte, supplying weighting agent for North Sea oil and gas drilling operations.

As an active mine, the site is not a heritage or access location: its surface footprint — described by the operator as under a quarter the size of the older Foss Mine's — comprises working mine buildings, a processing plant and haul roads rather than historic remains.

This is an active mining operation. It is not open to public access, and this entry describes its history and general location only.

Duntanlich is a live, operating mine, not a heritage or access site — this entry describes history and general location only, and is not a visiting or access guide.

Recorded claims

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

• A mine at Duntanlich was first proposed around 1992 and rejected; a second application was turned down on appeal at the Court of Session in 1996 on environmental grounds; a third application was approved by Perth and Kinross Council on 14 September 2016 by an 8-3 vote. ¹
• M-I SWACO developed Duntanlich to replace the depleting Foss Mine as the UK's domestic source of baryte for North Sea drilling fluids; the identified resource exceeds 7.5 million tonnes, with planned production of up to 120,000 tonnes a year. ^1,2
• Surface infrastructure — around 15km of access roads, a processing building, weighbridge and welfare facilities — was completed in December 2020 at a cost of about £9.7 million across a 183.5ha site; Foss Mine closed in 2021 once Duntanlich came into production. ³

Sources

1. (secondary) Go-ahead for barite mine at Perthshire beauty spot — The Courier
2. (primary) FAQs — Duntanlich Mine — Duntanlich Mine (M-I SWACO / Schlumberger, official site)
3. (secondary) Duntanlich Mine surface infrastructure — Robertson Group (civil engineering contractor)

Record created: 26 August 2026 · Last researched: 26 August 2026