HISTORY AND GEOLOGY OF THE OCHER MASSIF

An origin in the seas...

230 million years ago, Provence is flooded by the seas. The sediments accumulate at the bottom and form the white limestones that will become the Mont Ventoux, the Massif du Luberon, the Sainte Victoire, the Calanques...

Around 110 million years ago, the seas deepened. Gray clays covered limestones; today we call this geologic time scale "the Aptian" (and "the Gargasian" related to it). The basin being filled, sands of green color due to the presence of glaucony (green mineral with iron atoms), are deposited on top of the clays.

...and the Tropics

A new upheaval occurs around 100 million years ago: Provence emerges in a tropical climate. The heavy rains affect the green emerging sands ; deep waters dissolve the trapped components of the sand. Glaucony releases iron, revealing goethite. The washout of the iron oxides continues, forming layers of white kaolinite.

The ocher sands are born and the lands of this new continent are naturally colored.