Mines De Pont-Péan

Useful Information

Location:	1 All. de la Clôture, 35131 Pont-Péan. (48.013114, -1.711155)
Open:	no restrictions. [2023]
Fee:	free. [2023]
Classification:	Lead Mine
Light:	Incandescent Electric Light System
Dimension:
Guided tours:	self guided
Photography:	allowed
Accessibility:	yes
Bibliography:
Address:	Mines De Pont-Péan, 1 All. de la Clôture, 35131 Pont-Péan.
As far as we know this information was accurate when it was published (see years in brackets), but may have changed since then. Please check rates and details directly with the companies in question if you need more recent info.

History

1628	ore discovered by Jean du Chastelet, Baron de Beausoleil et d'Auffembach, and his wife Martine de Bertereau.
1628	exploitation concession for Yves de Liscoët, Seigneur de Coëtmen, but no mining.
11-FEB-1730	concession awarded to Noël Danycan de l'Epine.
1730	mine opened, managed by a younger member of the family, Thomas Harrington, seigneur de la Corderie.
NOV-1755	Pierre-Joseph Laurent diverts the Seiche river to move it away from the mine to reduce the water in the mine.
1794	mine closed for various reasons.
1844	mine reopened, first by washing the slag heaps on the surface with 25 workers.
1852	beginning of underground mining.
02-APR-1904	mine flooded after a strong water inrush.
1928	mine reopened, miners town erected, new headframes, water pumped out.
1932	mine closed.

Geology

About 300 Ma ago a rift system formed 20 km long and 300 m wide, running northwest and the turning eastwards. It is called Pontpéan fault, and allowed magma to penetrate the crust and form diorite veins. Further tectonic movement created more cracks which were filled by hydrothermal convection with sulfur-based minerals. This sulphide mineralisation contains mostly galena (PbS) and blende (ZnS), in lesser quantities pyrite (FeS₂), barite (BaSO₄), and chalcopyrite (CuFeS₂).

Description

Mines De Pont-Péan (Mine of Pont-Péan) is named after the town Pont-Péan, where it is located. Jean du Chastelet, Baron de Beausoleil et d'Auffembach, and his wife Martine de Bertereau were mineral prospectors for Henri IV and later for the superintendent of mines of Louis XIII. They discovered a lead vein containing silver, vitriol, sulphur, zinc, mercury, and arsenic at one end of the Tellé moor in 1628. But they were accused of charlatanism and expelled by the provost of Morlaix, La Touche Grippé. They complained, which was interpreted as audacity, and so they were imprisoned for life.

The Seigneur de Coëtmen, Yves de Liscoët, received an exploitation concession in 1628 and had it renewed in 1698, but he did not engage in mining. Mining started after the concession was awarded to Noël Danycan de l'Epine on 11-FEB-1730. He was a shipowner from Saint-Malo, founded the Compagnie des mines de Bretagne, also called Compagnie des mines de Pontpéan. He was already 74 at this time, the mine was actually operated by his wife Marguerite Chantoiseau, together with François de Blumenstein, squire of Germanic origin, naturalized French and concessionaire of the Forez mines. The mine was then managed by a younger member of the family, Thomas Harrington, seigneur de la Corderie. The mine was quite successful, only two years later it employed 300 workers. The mining started in 1730 in open cast mines on the surface, at the northern end of the metalliferous zone, the mining extended towards the south. Between 1730 and 1740 several shafts were sunk. But in 1740, the mine had financial difficulties, the concession was put up for sale and Marguerite Chantoiseau bought it in 1746. The main problem at that time was the water in the mine. Marguerite Chantoiseau diverted the Seiche river in order to keep it away from the mine, which worked rather well. Again she got financial difficulties, and in 1765 the concession was sold for £195,000 to the Compagnie des Mines de Basse-Bretagne. They started draining the mine with a steam engine powering a pump. The more important shafts were the Boulangère shaft (1780), the Deputies shaft (1789), Orme shaft, and the shaft of the Republic (1794). A total of 26 shafts was sunk for the exploration or the exploitation of the vein.

The mine was closed in 1794 or 1796 due to numerous difficulties, mainly the need to add additional dewatering machines. Unfortunately, the obligation to deliver the lead to the naval arsenals at a price fixed by the government and paid for in assignats made the mining unprofitable. It was closed until 1844, when it was reopend and was quite successful for many years. In 1895 the production was reduced, the mining equipment was too old, the mine was not very profitable anymore, and so a massive water inrush on 02-APR-1904 flooded the mine quickly and it was closed. The reopening of the mine in 1928 was in fact a fraud, the mine was pumped out, and a mining town was built, but this actually only served to embezzle the money invested. The scam collapsed in 1932, and the mine was finally closed, the houses of the miner town were never inhabited. From 1937 to 1941 and then again from 1951 until they were exhausted in 1955, the dumps were reworked with a modern ore wash.

This is not a show mine, it's more like an open air museum with a series of buildings from the mining history which are now Historical Monuments. The houses of the mine director, the doctor, and an accountant still exist, also some miners' homes and the old mine hotel. The chateau de Carcé was the first official accommodation for mine directors, first it was rented and in 1754 it was purchased by the company. But when the mine was first closed in 1798, it was sold. Then there are the office building, the workshops, and the miner's locker room; the latter was converted into a chapel, and a bell tower was added in 1908. The buildings are freely accessible, but only from the outside, as far as we know, there is no museum and no possibility to go inside. The local non-profit Association Galène plans a museum for years, but it does not exist so far. But there are several educational signs, so it is actually more like a mining trail. There are so many mining remains that you can walk around sightseeing for several hours. The mine is not accessible anymore, as it is completely flooded.