Conservation, management and valorization of geomorphological heritage in ‘geological’ nature reserves: the case of the Vigny quarry (Vexin, France)
Résumé
Located in the French Vexin to the NW of Paris, the Vigny quarry is a geosite of international relevance, recently classified as a Regional Nature Reserve (RNR) of geological interest (in 2009). Exposing reefal and peri-reefal limestones of Palaeocene age, the site was considered by E. Desor (1846) as the co-stratotype – together with the Danish series of the Fakse quarries – of the Danian stage. Furthermore, the Vigny limestones contain the richest Danian molluscan fauna in Europe and are the only known reefal complex of Tertiary age from the Paris Basin. As a whole, the Vigny quarry exhibits various aspects of geoheritage of great scientific and educative value: stratigraphy, palaeontology, sedimentology, tectonics… Geomorphological heritage is one of the major interests of the geological nature reserve. The site is a veritable open-air museum of palaeolandforms of various types, including palaeo-fault scarps with well-conserved tectoglyphs (striation features, coatings), palaeo-submarine landslides (slumping with olistoliths of reefal limestones, debris- and mud-flows of fluidized chalk), Pleistocene palaeosols with cryoturbation features, etc. The development of lookouts and scenic vantage points along a “geomorphological” trail still increases the interest of the site for geomorphology. Protection of geomorphological heritage and other geological features was made possible by 2003 with the land acquisition by the Val d’Oise Departemental Council, which developed an exemplary strategy of conservation, management and valorization of the geoheritage (security setting, pedagogic facilities and tools, information panels, website for school education, museography, mainstream publications…). With its recent classification as a Regional Nature Reserve, this reinforces the protection status of the Vigny quarry and extends the program of conservation, management and valorization of this unique geoheritage of the Paris Basin.