This clear geological outcrop enables an instructive short excursion in an otherwise very sporty area. Here you can immerse yourself in the Earth Age, some may be reminded of their school days, others of their university days. The recognizable strata show geological epochs in the limestone area of the Briançonnais from the Jurassic period.

Access by public transport

There is no stop very close by. The nearest bus stop is about 2km away and is on the main road N94 under the village of Saint-Crépin. Lines 69 and 541 in the Zou! (only french) regional network stop here. Trains no longer stop in Saint-Crépin.

From the Saint-Crépin bus stop at the roundabout, first across the railway tracks and then across the Durance river. Immediately afterwards turn right and always take the road on the right at the junctions. This is how you get to a parking space in front of a barrier. At the top left you can see a viewing platform and panels.

The walk from the bus stop is also shown on the map on this page.

Access by car

In the Durance valley, look for Saint-Crépin, the town is about halfway between Briançon to the north and Embrun to the south. Leave the main road N94 at the roundabout at the foot of the village of Saint-Crépin in the other direction to Champcella and the gliding airport (aérodrome). Pass over the railway tracks and the river bridge, then always right along the Durance to a larger square in front of a barrier.

Parking is easy at the foot of the geological formation.

Site history

It's not entirely natural that we can see the strata so well here. Gravel is still being mined further back and the original cone of rubble was also cleared here.

Description

The sedimentary rocks of the Barrachin escarpment recorded the paleo-environments (landscape, climate, etc.) of the Briançon area between 240 and 220 million years ago.

From the terrace, we first notice carbonate sedimentary rocks with alternating dark and light beds. The dark parts are limestone formed in a marine sedimentary basin. The clear parts are dolomite formed by precipitation in coastal lagoons in hot climates. These sequences are repeated several times.

On the lower part, we see irregular structures, these are bioturbations in the dolomite, formed by crustacean burrows. These forms prove the low depth of the waters in the past (less than 30 meters). Thanks to these fossils, we were able to date this stratum to the Triassic.

At the top, limestone beds show thin horizontal stripes. These are stromatolites, it is a limestone of biogenic origin resulting from the action of bacteria in shallow and warm waters (around 30°C).

In some places, we can see vertical displacements in the layers. Those with a straight and smooth limit are normal faults, the deformation is brittle and it took place after sedimentation. Other deformations affect the strata by giving them curvatures. Here the action of a force has acted on the mud in the process of induration. The forces in action can be earthquakes or displacements due to the weight (landslides).