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Theodore Mine

Theodore Mine

Nature, culture and fertilizer in Alsace

In 1904, potassium deposits were discovered in French Alsace. Potassium, or potash, is one of the most essential nutrients for plants, together with nitrogen and phosphorus. That is why potash was brought out en masse to make fertilizer.

The Amélie mine was the first to extract potash (or 'potasse') in 1908 in the French Alsace region. The mine's name was a tribute to Amélie Zurcher. She encouraged exploratory drilling and hoped to discover coal. Instead, Zurcher came across potassium-rich ores. Further research showed that the potassium basin spread north of Mulhouse.

Potassium sulfate

The ores were located 400 to 1,000 meters underground and were one of the raw materials to produce fertilizer. From 1920 onwards, the Produits Chimiques de Tessenderloo, among others, used the potash from the Mines domeniales de potasse d'Alsace to make potassium sulfate.

Port of Antwerp

The potash was poured from Mulhouse onto trains bound for Strasbourg. There, the potash was shipped to Antwerp. The port of Antwerp became a hub for storing and exporting potassium salts from Alsace.

Dozens of other potash mines followed in the wake of the Amélie mine, including the Puits Théodore, also in Wittenheim. Around 1950, the potash mines in Alsace reached their absolute peak. In 24 different pits, 14,000 miners went underground to extract potash.


The 65-meter-high headframe in the Puits Théodore dates from the heyday of potash mining in 1958.

From the 1960s on, it went downhill. The mines were depleting and not profitable anymore. The last potash was extracted in Puits Théodore in 1986. Alsace's last active mine closed in 2002. Appropriately enough, it was the Amélie mine, the place where the rush for potash had begun a century earlier. Ultimately, five hundred million tons of raw ores were extracted in Alsace.

Fire brigade

Today, a handful of mines remain. For example, the 65-metre high headframe marks the Puits Théorode, where you will also find a historic fire station building.

Firefighting equipment was stored in the building and the pipes were hung to dry in the wooden tower.

The immediate presence of firefighters was not an unnecessary luxury. In March 1919, 26 miners were killed in two separate incidents in this mine. A monument at the Puits Théodore commemorates the 800 deaths that occurred over a century during the mining of potash in Alsace.

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