National Geology Weekend 2021.
© Société géologique de France
With the planet at the centre of everyone’s concerns, the French Geological Society (SGF) is encouraging all geoscience stakeholders across France to engage with the wider public to make people more familiar with the beauty and history of our landscapes and the Earth’s precious resources.
Over 3 days, you will learn about the geodiversity of our landscapes, our coasts and even our cities. A wide range of events will take place, including:
- field trips,
- geowalks to learn about the kinds of building stone used in our cities,
- film screenings,
- museums opening especially for the occasion, and
- virtual events.
Two hydrogeological tours with BRGM
BRGM is taking part in two groundwater-related events during the National Geology Weekend:
Hydrogeology of Thau-Balaruc: a sweet-salty and hot-cold cocktail
Friday 28 May from 9am to 5pm - Balaruc-les-Bains (Hérault)
The Balaruc peninsula is exceptional from both a geological and hydrological point of view. So many questions on such a small area: what is the origin of the thermal water at the Balaruc-les-Bains spa? Where does the drinking water drawn from Issanka to supply Sète come from? Why does an underwater spring mysteriously reverse? Different waters circulate and mix under our feet: hot, deep thermal water, salty seawater, and cold underground freshwater recycled from the rain. In order to better manage and protect these strategic resources of thermal and drinking water, a local consortium of scientists and companies is studying the geology of the natural underground reservoirs of Balaruc. To get the cocktail recipe, you have to be familiar with the shaker!
Tours of the site and the deep drilling project (in progress) guided by geologists and hydrogeologists, presentation of the rock cores sampled at depth and discussion of the evidence of water circulation and mixing. Short one-hour tours for groups of up to 15 people.
Hydrogeological excursion in the village of Plessix-Balisson
Saturday 29 May from 2 to 4 pm - Bourg de Plessix-Balisson, Beaussais-sur-Mer (Côtes-d'Armor)
A presentation lasting under an hour on groundwater and the way it functions in theory, followed by a walk in the village of Le Plessix-Balisson to identify the different types of rocks, their characteristics, their uses and their relationship with groundwater. In a second stage, we will track the groundwater on the rocks and check how it functions in theory through the rocky outcrops of the village and along the developments that have been built. Finally, we will highlight the hydraulic developments in feudal times on the basis of the hydrogeological characteristics of the site, the feudal mound or the Plessix-Balisson château.