The surprising influence of salt on the Spanish Pyrenees
Pushing through the rock and clay of the Pyrenees Mountains are layers of evaporite, a.k.a. salt. It’s the last thing you’d expect to find so far inland. But, of course, there’s a perfectly (geo)logical explanation!
What’s equally amazing is the impact that the presence of this salt has had on the area’s development, beyond the geology. Over millions of years, the salt has influenced the area’s prosperity, gastronomy and technology as well as the geological landscape. Here’s how.
Salt and the Spanish Pyrenees’ landscape
When seas are isolated and dry up, layers of salt form from evaporation. Around 200 million years ago, this process created the salt now found in the Pyrenees. Then, over time, the thick layer of salt left behind was buried beneath more layers of clay and rock.
Around 55-25 million years ago, as the Iberian Peninsula slowly crashed into Europe and formed the Pyrenees Mountains, that layer of salt ascended and pushed its way up, through the more brittle layers above. This exposed natural salt body is known as a diapir.
One of the best places to see this exposed layer of salt is Cardona Salt Mountain, around 55 miles (90km) northwest of Barcelona. Unique in Europe, the mountain is almost pure salt, and still marked with the beautiful patterns that formed when the salt flowed like treacle. Amazingly, Cardona Salt Mountain is still growing – at around the same rate as it is eroded by rain!
Salt and trade in the Spanish Pyrenees
The salt deposit in this corner of the Iberian Peninsula has played an important role in the development of the region’s trade. It has been mined since Neolithic times, the Romans had their fill of it, and the salt significantly contributed to the economy throughout the Middle Ages. In fact, the salt was so vital that it became known locally as ‘white gold’. It’s thanks to this ‘white gold’ that the knights of Cardona became the most powerful family in the Catalonia region; expansions to Cardona Castle in the 12th to 15th centuries were even financed by the salty treasure.
The salt mine remained vital throughout the 20th century as a source of potash, which is mostly used in fertilisers. It was eventually closed in 1990, then reopened as a tourist attraction. In 2023 we took a small group to Catalonia which included a private guided tour of Salt Mountain Cultural Park. Read customer reviews from the Catalonia trip here. We expect to repeat this tour in April/May 2025. Call or email our office to express interest in joining the 2025 trip and secure your place. (Maximum 12 places)
Salt and food in the Spanish Pyrenees
With so much salt lying around, it’s understandable that it found its way into the local cuisine!
One of the best places to see how vital salt was to the local gastronomy is L’Escala, a working fishing town on the Costa Brava. It’s known for its excellent anchovies! The 325-year-old salt exchange building still stands proud in the centre, across town from the Salt and Anchovy Museum. Every September, L’Escala’s Festival of Salt celebrates the town’s fishing and salting traditions. Whether you visit during the Festival of Salt or not, don’t miss the chance to taste what locals say are the best anchovies in the world!
Salt and modern technology
Uses for halite – better known as rock salt – go well beyond food and fertiliser, and more uses are being explored all the time, such as making superblack coatings, fabrics out of wood pulp, and brightening clouds to protect reefs. One of our favourite uses of halite is extracting oxygen from the lunar regolith*!
Find out more about – and taste for yourself – the profound influence of salt on the Spanish Pyrenees on one of our upcoming geology and culture tours: -
If you would like to join a group tour to the Spanish Pyrenees in 2024, look at The Geology of the Pyrenees, Aragon, Spain (15-21 Sept 2024)
*Regolith definition: the layer of unconsolidated solid material covering the bedrock of a planet – or in this case, the moon!