The area around our cottage is the place to be for those interested in geology because all sorts of rocks can be found:
The peak in front of the cottage is made of sedimentary rocks, named a karst (see post "nice walk up to the top").
In the valley, around the farm, a large scope of metamorphic rocks can be found including a layer from Precambrian 900 million years (upper brioverian), pictured here. Those rocks can be seen thanks to several geological trails.
And South (around Lampy lake) and North (Sidobre area) are made of igneous rocks.
This diversity of substratum is one of the main reasons of the great biodiversity of the region.