Geology-Areas of interest-Eastern Barronies and Digne area

Conditions, triggering mechanisms and signification of post hiatus Cenozoic sedimentation?

The External Alps recorded an integral Wilson cycle initiated in the early Mesozoic by an extensional event leading to the jurassic opening of the Vocontian Basin. Upper cretaceous inversion of structures and onset of the early Cenozoic alpine compressive phase completed the cycle.

The mesozoic tectono-sedimentary evolution of the area, as well as the miocene alpine phase, are relatively well constrained in the eastern Barronies. Even if of prime interest, as the series recorded both pyreneo_provencal compression and ECRIS extension at that time, Paleogen -and particularly the Eo-oligocene interval- did not paid such attention until now. This is probably due to: (1) a lack of sediments preservation from early Cretaceous to late Eocene (2) an inaccurate stratigraphic frame for Eocene et Oligocene deposits, making the sedimentological, paleoenvironnemental and structural contexts uncertain.

A study, focussing on the first syn-orogenic non marine deposits of the area, is in progress (PhD Alexandre Hamon). This work aims at deconvoluting the climatic, tectonic and halokinetic signals within a tardi-Eocene to Oligocene breccia, deposited after the cretaceous hiatus.