Established in 1987, it occupies an area of 0.61 hectares, making it the smallest national nature reserve in France.

It consists of two former open-air quarries separated by a few hundred meters in the Thouet valley.

[3][4] Its total area spreads overs 0.61 hectares[1][2] (or 6 100 m2), making it the smallest national nature reserve in France.

Each horizon correspond to a period of approximately 260 000 years, and is characterized by one or several specific ammonite species.

Article 5 indicates that "it is forbidden to harm in any way the coal front, the mineral substance or fossils from the reserve.