LE PLAN DE PHAZY
Why do these particular extremely saline hot springs exist here ?Geologists have a simple answer. We are located on the Durance fault zone which is open down to a depth of 1000m. This fault is still active and micro-earthquakes are a common occurrence.
Why is the water hot? The water runs down the neighbouring Combe Chave and Risoul mountainsides. It seeps into the fault where it is heated ( 1° centigrade every 33m), and then rises back to the surface.
The water is rich in mineral salts dissolved during this journey and the hydraulic action is that of an Artesian well.
Analysis reveals that the water is rich in iron (brown colour of deposits) in magnesium (laxative effect) sodium, chloride and sulfate. The water is modified by surface water flows that reduce the temperature and density of the salts. When the water spurts out of the spring, a large amount of carbon dioxide is also released.
The Swiss or vine spring beyond the greenhouses has a flow rate of 300 litres per minute at 26°. The Rotonde spring has a flow rate of 70 litres per minute at 28°.
The area is covered with a layer of hard tufa formed by the salts.
The flowing of salt water constitutes an ecosystem that can be described as Atlantic marshland (salt meadows) with distinctive vegetation.
What are the biological properties of the waters ?
- The action on skin diseases, atopic eczema in infants, Leiner moussus disease, skin allergies or infections is impressive. The latest plans to exploit the waters included making cosmetics with mineral salts from the water.
- soaking in the waters, as in any hot saline water, is extremely beneficial for joint problems, post traumatic disorders and rehabilitation of limbs.
Taken orally the taste is off-putting but it seems there are certain effects:-
- it stimulates the intestines, and was taken by the village elders for seasonal purges.
- diuretic action.
The Rotonde was built by the Department in 1824. The spring spouted in the centre of this small thermal spa, encircled by a series of wells which captured the water. These were accessed by staircases. The building was heated in all seasons by the hot water, at a temperature of 28°.
In 1845 the Town Hall took over its upkeep.
The 1824 Rotonde has been restored and is now an exhibition centre for local produce. The spring in front of the Rotonde has been developed with facilities for tourists, including bathing pools, benches , a car park and snack bar, and is regularly controlled.