| Couches de l’Aroley | |
| Period: | Barremian |
| Age: | Barremian |
| Type: | Geological formation |
| Prilithology: | Calcitic schist |
| Otherlithology: | Fine conglomerate |
| Namedfor: | Plan Aroley |
| Region: | Savoie |
| Country: | |
| Unitof: | Valais trilogy |
| Underlies: | Couches des Marmontains |
| Overlies: | Brèches du Grand Fond Group |
| Thickness: | Averaging 100m (300feet) |
The Couches de l’Aroley (short: Aroley Formation) are a sedimentary formation deposited during the Early Cretaceous (Barremian to Aptian). They consist of calcitic schists with dolomite clasts interbedded with finegrained conglomerates. The whole sequence is about 100 m thick.[1]
The Couches de l’Aroley are the lowest of the three post-rift sequences deposited in the Valais ocean. It overlies syn-rift sequences of the Brèches du Grand Fond Group.[2]
The Aroley Formation can be found within the following nappes:
The type locality is the Massif de la Pierre Avoi, in Saxon, Valais, Switzerland. The formation is named after a "Plan Aroley" which lies below the Pierre Avoi. It was first described by Rudolf Trümpy 1952.[3]
The Couches de l’Aroley can be correlated with the Klus Formation and the Tristel Formation found in eastern Switzerland, the Engadin window and the Tauern window.[4]