Toarcien National Nature Reserve

The Hauts-Côteaux quarry presents a cross-section significantly more developed than the Groies quarry. It bears, from bottom to top :

• ferruginous sandstone and gravelly limestone (> 0.50 m). It includes few fossils, notably bivalves (Pectinidae), gastropods and belemnites, and shows very numerous worm borrows ;
• bioclastic limestone with ferruginous oolites (1.20 m). It is extremely rich in bioclasts (essentially fragmentary shells of bivalves and gastropods) and ferruginous oolites, small spheres made of thin concentric layers of iron oxide. Ammonites and belemnites can also be found. Those are dated from the Early and Middle Toarcian ;
• argillaceous limestone alternating with marl (6.90 m). It contains also numerous fossils of pelagic organisms, mostly animals who lived in open waters (ammonites, nautilus, belemnites...). It spreads from the late Middle Toarcian to the Early Aalenian.[3]

The nature reserve was established by decree the 23 November 1987.[2] Articles 5 to 11 of the decree regulate the reserve and specify several restrictions. Article 5 indicates that "it is forbidden to harm in any way the coal front, the mineral substance or fossils from the reserve.[2]"