This contrasting landscape, where the curvature of the Cousson mountain massif to the south-east contrasts with the sharp pyramid-like peak of the Pic d'Oise to the south, is made up of two distinct geological areas or zones:
- The indigenous, original terrain, from the Pic d'Oise peak to the Bléone valley. This undulating terrain is made up of sandstone from the Tertiary Era and Valensole's stony and gravelly mixed-rock deposited-composites.
- The allochthonous soils, or non-indigenous soils (i.e. displaced after their original deposition) provide a more marked and distintive landscape,
essentially composed of limestone and marl from the Secondary Era, belonging to the Digne geological-nappe (or geological thrust-sheet), consisting of the Barre des Dourbes mountain, the Cousson mountain and the Couard peak.
The Cousson, the emblematic mountain of Digne and its surrounding area, has two peaks. It is the goal and destination of many Sunday walkers, but also an ancient place of pilgrimage. The Chapel of Saint-Michel (Saint Michael's Chapel), a modest Romanesque building whose construction date is unknown, is perched high on a steep slope. It is one of the 6 chapels that form the so-called "mystical crown" that surrounds the town of Digne-les-Bains.
The Pic d'Oise peak is recognisable by its particular pyramid shape. At the end of the afternoon, the shadow of this immense pyramid stretches in a particular way that can be use to indicate the time. At the foot of the Pic d'Oise peak, the site of the old village of Champtercier can be seen.