The topsoil is light and acidic. It comprises fine clayey quartz sand coloured by small amounts of iron hydroxide and marine sediments known as “sables fauves”.

Deep down, the Oligocene aquifer system consists of marine limestone and is covered by Miocene sedimentations which had two marine stages, the Aquitanian episode and the Helvetian episode, forming new calcareous deposits widely drained by rivers and streams. This limestone is covered by late Miocene and Pliocene clayey-sandy formations called “sables-fauves”. There are various thicknesses of these sands on the property. They are semi-permeable and are drained by many different springs which flow in the direction of the Helvetian limestone, forming small canyons that can be up to 35 meters deep.