On Saturday I am leading an outing with ecologist Francois Lefebvre to one of our favourite nature sites, la Cabane, on behalf of the Association de Patrimoine Vivant de la Claise Tourangelle (PVCT), the Association de Prehistoire et d'Archaeology de Bossay (APAB) and the Association de Botanique et de Mycologie de Sainte Maure de Touraine (Botamyco37). As we wanted to focus on both the industrial and the natural history of the site I have prepared a document on the history of the china clay (Fr. kaolin) extraction on the site. Those participating in the outing will get it in French on the day, blog readers will get it here in English.
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Kaolin, or ‘china clay’ as it is commonly called in English, is a rock from which the clay mineral kaolinite is derived. This has been used for many years as the principal ingredient in porcelain tableware. Today its uses range from paper to paints, fiberglass to cosmetics and pharmaceuticals, as well as in sanitary porcelain.
Kaolin is a hydrated aluminum silicate crystalline mineral formed over many millions of years by the hydrothermal decomposition of granite, feldspars, mica and quartz sands. The clay can be modified using high temperatures to create products with different characteristics eg whiter, harder, better electrical conductivity.
Clay storage hangars at Imerys Ceramics, Tournon Saint Martin.
The discovery of kaolin in Saint-Yrieix-la-Perche (Haute Vienne) in the late 1760s was pivotal for the local economy. This high-quality white clay became essential for the porcelain industry, particularly benefitting the famous Limoges porcelain manufacturers. By the 19th century, Indre's kaolin mines, notably in the town of Argenton-sur-Creuse, were thriving. These deposits contributed significantly to the region's economic development, enabling the production of fine porcelain that gained international acclaim.
However, by the late 20th century, the industry faced decline due to the depletion of easily accessible deposits and competition from kaolin sources worldwide. Despite this downturn, the historical impact of kaolin extraction remains evident. Today the activity continues with Imerys Ceramics, based in Tournon Saint Martin, and one of the largest kaolin producers in the world.
Imerys Ceramics, Tournon Saint Martin.
At la Cabane, an initial request to quarry was made by Denain-Anzin Mineraux in 1972 but there had been a quarry on the site since 1964 and Denain-Anzin Mineraux had been active in the area since 1959. The company sold their mining business in Indre, Indre et Loire and Vienne and the equipment associated with it to WBB de France for 35 000 francs in 1978. WBB continued to exploit la Cabane until 1983, when the quarry was abandoned. The equipment at the time of the sale included three trucks, a loader and two diggers, as well as clay drying and processing equipment and two storage hangars at Tournan Saint Martin station. WBB de France was a French branch of a British company based in Devon called Watts, Blake, Bearn and Company Limited. Denain-Anzin Mineraux were bought out by Imerys in 2005 and WBB no longer exists.
The land was owned by a third party and Denain-Anzin only had the mineral extraction rights on 7 hectares at la Cabane and la Touche au lard. The industrial clay was from one to three metres thick, under two to five metres of topsoil, sand and gravel. It was extracted from an open cut mine by hydraulic digger. In the three years prior to September 1971, just over ten thousand tonnes of clay had been extracted, destined for ceramics factories. The site was divided into zones, each of which was dug successively. The top soil was removed, the clay extracted, then the exhausted zone was back filled with the topsoil from the next zone. Denzain-Anzin Mineraux was obliged by the terms of their mining licence to restore the land to a state where it could be cultivated, and all infrastructure was supposed to be removed. The remains of the quarry itself had to be left with clean stable sides, and if there was a risk it would be used as a rubbish dump, Denzain-Anzin Mineraux were obliged to fence it off before they left.
What the quarry looks like now.
WBB de France exported 75% of the half a million tonnes annually of clay they excavated globally to their subsidiary in Germany. They operated four quarries near Tournon Saint Martin and in 1977 sold 13 000 tonnes from this production, 30% of it exported. After investment in equipment production was expected to rise to 30 000 tonnes. Their local manager was Monsieur P. Andrei, and everyone I spoke to referenced him as the person I should go to for information, but sadly I understand that he has now died. His boss was an English engineer called Geoffrey Dawes. I had hoped to get an idea of the day to day working of the enterprise, but although I spoke to a relative and others who knew Monsieur Andrei, no one was able to give me any details. Imerys Ceramics did not respond to my email. My understanding is that the clay was loaded on to trucks and transported to the railway station at Tournon Saint Martin, where it was stored for subsequent transportation by rail to Germany. What I have been unable to work out is at what point the clay was dried, but it must have been either on site at la Cabane or at the storage facility in Tournon Saint Martin.
When the business changed hands in 1978 the Prefecture, the sub-prefecture at Loches, the mayor of Bossay sur Claise, the State Service for Industry and Mines, the Directors of the Departmental Equipment, Agriculture, and Antiquities services and the Architect for Batiment de France (historic architecture and monuments) were consulted and had to give their permission. The Departmental Mines Engineer and the Gendarmes were notified.
The gap between the trees is the dam wall dividing the quarry from the drainage ditch.
When WBB decided to close the mine in 1981 they notified the Departmental Mines Engineer, advised that previous exploitations had been left levelled, grassed over and ready for cultivation. All of the above authorities were once again advised. Denain-Anzin Mineraux also had to provide a statement that they were no longer involved and provided a photo of how the site had been left. They agreed to the following actions for the existing quarry:
1. the base of the quarry was leveled.
2. the edges were banked at 30° and covered with topsoil so they would revegetate.
3. a dam wall was created between the quarry and the drainage ditch.
4. the storage area was cleaned, leveled and put to grass.
5. the concrete pad was left, to provide a storage space for agricultural material.
So nowadays we may get the impression that la Cabane is a wild untouched site, but in fact it has been greatly impacted by man's actions in the 20th century. But it has now had several decades of 'rewilding' and natural regeneration, and has become a site rich in biodiversity, worthy of being declared a Zone Naturelle d'Interet Ecologique, Faunistique et Floristique (ZNIEFF) in 2022.
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Many thanks to Jean-Marie Millet, who took it upon himself to act as my 'archive rat', and found several very instructive documents. Thanks also to Simon, who did much of the internet searching and ran what we had through ChatGPT to provide an initial draft. That saved me a lot of time. I then edited it, passed it to Francois for his comments and we whittled it down to under two pages for the handout.
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