Trésor géologique sur notre terroir

“It was in 1972, when we were ploughing a plot of land near the château to establish a plantier (young vine), that we discovered a large, round pebble weighing precisely 502 kg”, reports Philippe Brunel, the third generation of the family. Since then, the huge pebble had been transported to and deposited near the winery, but no one paid it much attention.

“During the last grape harvest in September 2020, the Maison des vignerons had the idea of launching a sort of challenge to find out which domaine in the appellation had found the largest rolled pebble in the Rhône on one of its parcels, and we took a renewed interest in it,” explains Patrick Brunel, Philippe's uncle, before he adds: ”Before informing the Maison des vignerons of the existence of our unusual pebble, we wanted to find out more about its origins. We called on Georges Truc, a former university geology researcher and specialist in Côtes-du-Rhône terroirs.

After several visits, the geologist declared: “This stone comes from about 300 km between the Rhône and Isère rivers. It's a block of quartzite (grains of quartz cemented by silica). Its place of origin is probably the Tarentaise valley. It was probably transported by a tree (stuck in the root), carried by the Rhône. Its age is around 240 million years, corresponding to the Triassic period. The Triassic is between 252 and 201 million years old and precedes the Jurassic". During his visits, Georges Truc was able to identify a number of other geological treasures, which make up a large part of the estate's soil. These include pebbles, the concretions of which are certainly stalagmites, formed by calcium carbonate deposits in open fissures dating from the Quaternary period (1.5 and 2.6 million years ago).

Le Dauphiné Vaucluse Matin Thursday, April 22, 2021