MANGANESE MINING

In Doddiscombsleigh

A study of the remains of the old undocumented manganese workings around this village in South-West England.

By Andrew Westcott

Doddiscombsleigh as seen from the opposite valley
A shot of Doddiscombsleigh from across the valley.

Introduction To Doddiscombsleigh And Its Mines

Doddiscombsleigh, occasionally spelt Doddiscombesleigh, is a small village located roughly six miles South-West of Exeter in the county of Devon, England and just one mile East of the River Teign and the Teign Valley. Doddiscombsleigh is within sight of the Haldon Belvedere tower which can be clearly seen on the Haldon ridge and the village is well known locally for its pub, the Nobody Inn and its church of Saint Michael.

It was here that I was born and spent my formative years, and it was partly because my parents owned a farm in the village that I was able to explore the fields and woodlands around Doddiscombsleigh with my friends and it was on some of these 'expeditions' that I first became aware of the evidence of early mining activities in and around the village, some on our property. It seemed nobody knew anything about the origins of these old mines, although the existence of "The Caves" in Scanniclift Copse was well known and I was prohibited by my parents from visiting the possibly dangerous old workings, but curiosity got the better of me so I did anyway, and as is so often the case with childhood interests, my fascination with these workings has stayed with me.

A Brief Geology Of The Teign Valley

Doddicombsleigh's location in relation to Dartmoor
Diagram 1
A diagram of the Dartmoor area showing the position of
Doddiscombsleigh in relation to the metamorphosed region.

The village of Doddiscombsleigh, geologically speaking, is placed on the outer perimeter of what is known as the 'metamorphic aureole' surrounding Dartmoor, this being the region of rock which was altered by the heat of the neighbouring intrusive magma mass which eventually cooled and solidified into the present granite batholith which millions of years of erosion have finally exposed, producing Dartmoor as we know it today. Ore bearing lodes were formed in this metamorphosed region by the action of fluids, principally water, carrying dissolved minerals from the magma into cracks and fissures in the surrounding rock where they were deposited. As a temperature gradient existed through these rocks, different minerals became deposited in the rock according to the distance they were from the magma body with, for example, tin being deposited at high temperatures in or next to the granite, a little further out copper would be found, with manganese being deposited at the low temperature outer edges of the aureole. The map in diagram 1 shows Dartmoor represented by the grey area, and the approximate line of the metamorphic aureole shown as a red line. This narrow region is where the local country rock underwent extreme changes and mineralization due to the close proximity of the magma mass. Much evidence of metalliferous mining can be found all around Dartmoor including the extraction of lead, copper, iron and tin, with the Teign Valley area being especially well known for its mining past.

A map of Doddiscombsleigh identifying the locations of the old workings
Diagram 2
Click on the numbered regions to take you to
the page dealing with that specific area.

The stretch of the Teign Valley between the villages of Dunsford and Chudleigh sits right on the metamorphic aureole surrounding Dartmoor and as there is a fault running along the length of this part of the valley, the region has become heavily mineralised and the area is well known for its historic mining activities which exploited the metalliferous ores to be found here. Some of these workings are well known, for example micaceous haematite was mined right up until about 1969 at Great Rock Mines near Hennock, and lead ore was once mined at Frank Mills Mine in the form of cerussite; galena, which is another lead ore was extracted at Wheal Exmouth near Ashton and barytes (Barite) mined at Bridford Mines up until 1958 with dolerite, although not actually an ore, still being extracted for roadstone near Trusham. These are the major enterprises but there were many smaller scale ones as well, and although most of these larger workings are well researched and documented, there is little or no mention of the small scale mines in the area, and the manganese workings in and around Doddiscombsleigh are no exception, there being no mention that I have been able to find other than a mention in White's Devonshire Directory of 1850 that "manganese was formerly got in this parish, but the mine was closed some years ago", so I feel I'm trying to fill an important gap with my little bit of research into these old workings, while there are still some remains to be studied. The map in diagram 2 is intended to be fairly specific and shows the parish of Doddiscombsleigh, along with the areas I'm attempting to study. The rock in this village consists predominantly of shale, although there is a dolerite pluton which outcrops near the top of the hill overlooking the village, and this has been quarried on a small scale for the hard stone in years past, leaving a small but visible quarry high up on the hillside.

In the South-West of England the main producer of manganese ore was initially the mine at Upton Pyne which commenced production in 1770, although the deposits there were gradually worked out and the mine closed in 1823, and from about 1812 onwards the main production was coming from mines in Tavistock and the Teign Valley in Devon, which presumably involves the mines being investigated here although there are more manganese workings near the village of Ashton, although again they are of small scale.

Manganese As A Product

Manganese ore itself occurs in two basic forms; Either as a primary deposit, which means the mineral is in the original form and location within the country rock as it was when it was deposited from the magma body, or a secondary deposit, which is where the ore was deposited as a sediment due to erosion of a primary deposit located elsewhere although both of these sources may be commercially viable, depending on the quantity and purity. Manganese ores come in various compositions such as carbonates and silicates but the oxide pyrolusite is the most widespread with manganite also of some importance.
As a side note, manganese also occurs in nodules on the ocean floor where various minerals have come out of solution under the intense pressures. Manganese can account for up to 25% of the volume of these nodules.

Manganese is a highly reactive metal with the chemical symbol 'Mn', an atomic Number of 25 and a specific gravity of 7.43 with physical properties which resemble iron, although it is harder and more brittle. It has many uses, although originally it was used in the glass making industry where manganese dioxide was added to the molten glass to improve its clarity by removing the green colour imparted to it by various iron compounds, although in modern times it is mainly used in the steel making industry where it is alloyed with iron to produce a superior quality of steel, this accounting for over 90% of worldwide consumption, although it also finds use as a depolariser in zinc-carbon dry cells in the form of manganese dioxide.

This study involves a large number of photographs as these form a major part of this work, so to make this area of my site a little more reasonable to download and view I have divided it up into four sections, one for each of the areas of interest plus this page which offers an introduction to the area and the project generally.

Click on one of the links below to take you to the page of interest.

Links to pages Description of content
Location 1
SX 844 863
'The Caves'
The adits located in Scanniclift Woods
Location 2
SX 849 867
'Big Bog'
An open-cast quarry
Location 3
SX 854 865
'The Rubbish Dump'
An exploratory adit half way up Down Lane
Location 4
SX 853 861
'Mistleigh Mines'
Old Exploratory workings in Mistleigh Copse

Much about these mines is guesswork as any records seem to be non-existent, so if anyone has any stories, or information on any of the manganese mines I'm studying here, whether factual or highly doubtful, third-hand or passed down from a grandfather, please contact me at the e-mail address below so we can add to the little we do know and hopefully put a few pieces of the jigsaw together, and attempt to get a better picture of Doddicombsleigh's mining history.

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© Andrew Westcott 2003 - 2010

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Location 1 - Ordnance Survey SX 844 863 Location 2 - Ordnance Survey SX 849 867 Location 3 - Ordnance Survey SX 854 865 Location 4 - Ordnance Survey SX 853 861