The stellar cluster of the Pleiads is depicted on two carved rocks in the Merveilles valley, in the mont Bego region, by six main zones, surrounded by several scattered cupmarks. On one of these rocks, referred to as “the Dancer”, the stellar cluster of the Pleiads is depicted above a carved halberd in a westerly direction, suggesting the heliac setting. On the other, the rock referred to as “the Pleiads”, the stellar cluster is depicted in the south, suggesting its zenith. Taking the precession of the equinoxes into account, it is possible to determine the date in the year of the heliac setting of the Pleiads in the west if the millennium is known. The latter is estimated between 3300 and 1800 years BC by comparing the types of arms carved into the rocks with those discovered in archaeological sites. Although today it is difficult to reach the Merveilles valley during the month of March because of snow, it was probably possible between 3000 and 2000 years before our era, at the end of the Atlantic period, during the Chalcolithic climatic optimum, when the climate was slightly warmer than at present.
Mount Bego, Rock carvings, Chalcolithic, Bronze age, Pleiads, Precession of the equinoxes, Sacred mountain, France