Discover France and Explore the Fossils and Geodiversity of the Vaches Noires Cliffs in Calvados
- Wayne Munday
- 37 minutes ago
- 4 min read
Sip back and discover France and explore the fossils and geodiversity of the Les Falaises des Vaches Noires or Black Cows Cliffs in Calvados stretching from between Houlgate and Villers-sur-Mer along Normandy’s scenic Côte Fleurie or Flowered Coast. Formed from the Marnes de Dives Formation during the Late Callovian Stage of the Middle Jurassic, these cliffs preserve grey marls, fossiliferous limestones, greensands, and glauconitic chalk deposited along the shallow margin of the Tethys Ocean. Their fossil record includes ammonites, belemnites, bivalves, sea urchins, fish, and spectacular marine reptiles such as ichthyosaurs, plesiosaurs, and crocodilians like Tyrannoneustes and Steneosaurus, alongside rare dinosaur remains transported from the Armorican Massif. Since the 18th century, naturalists from Georges Cuvier to Philippe Taquet have studied this site, which today remains central to debates over fossil collecting and conservation. While direct access to the unstable cliffs is restricted, guided tours from the Paléospace Museum in Villers-sur-Mer offer visitors a safe way to explore Normandy’s deep-time heritage and reflect on the region’s Jurassic past, perhaps ending the day with a glass of local Calvados.
This protected stretch of coastline between Houlgate and Villers-sur-Mer is renowned for its dramatic badland relief, sculpted ravines, and rich Jurassic Period geology, offering visitors exceptional opportunities for coastal walks, photography and fossil hunting at low tide. With easy access from Deauville and Caen, visitors can follow the coastal path toward Villers-sur-Mer, home to the Paléospace Museum, which showcases the region’s dinosaurs, marine reptiles and ancient marine ecosystem. The broader Calvados region is equally defined by its celebrated AOC Calvados designation for its apple-and-pear based brandy produced by Distillerie Busnel, Distillerie Peremagloire. Christian Drouin and Manoir d'Apreval. Again, Normandy’s climate, geodiversity and traditional distillation methods have a significant influence upon the regions terroir.
Since the 18th century, prominent French naturalists such as Jacques-François Dicquemare (1733-1789), Georges Cuvier (1769-1832), Eric Buffetaut and the late Philippe Taquet (1940 – 2025) have studied the fossils from these cliffs. In recent years the Cliffs have been at the center of a much debate over fossil collecting and conservation. The French government has proposed classifying these fossiliferous cliffs as a national nature reserve, which would prohibit the removal of fossils and minerals. This has sparked local opposition for the continued access to the foreshore. Fossil hunting in Normandy is currently guided by local safety rules and environmental respect rather than a formal code like the UK’s Jurassic Coast. Visitors are advised to collect only loose fossils from the beach, avoid dangerous cliff areas prone to landslides, and check tide schedules before exploring. Digging into bedrock is forbidden, and significant finds should be reported to the Paléospace Museum in Villers-sur-Mer. Guided walks offered by local museums provide a safe, legal way to experience Normandy’s geological heritage, ensuring fossil collecting remains both educational and sustainable for future generations.
The Vaches Noires Cliffs are primarily made up of the marine sediments from the Marnes de Dives Formation dating to the Late Callovian Stage of the Middle Jurassic. The Marnes de Dives Formation is composed of grey marls, fossiliferous limestones, greensands and white glauconitic chalk that were deposited along the shallow northern margin of the Tethys Seaway connected to an expansive tropical sea that covered much of Western Europe at the time.
During the Late Callovian the coastline of Normandy lay on a warm tropical to subtropical marine shelf where fine muds, ooidal sediments and abundant marine life accumulated in a calm and open-marine environment. The presence of glauconite, a distinctive dull-green mineral, only forms under slow sedimentation, moderate oxygen levels and mineral-rich seawater and further confirms the presence of shallow-marine conditions that shaped these deposits.
Ongoing erosion today continually reshapes this Normandy coastline carving a striking badland landscape of ravines, pinnacles and gullies. The combined effects of marine undercutting, intense rainfall, and the inherently unstable clay cliffs trigger frequent landslides, mudflows, and rockfalls, constantly reorganising and reshaping this soft-rock landscape. These dynamic process define the Côte Fleurie and create an ever-changing landscape that captivates visitors and fossil hunters alike.
The shallow-marine environment of the Tethys Ocean as preserved in the marly sequence of the Marnes de Dives Formation has a remarkable biodiversity that includes abundant ammonites, belemnites, bivalves, sea urchins, fish skeletons and a diverse number of marine reptiles such as ichthyosaurs, plesiosaurs, and marine crocodilians like Tyrannoneustes and Steneosaurus, along with rarer dinosaur remains.
Many dinosaur bones, including those attributed to theropods such as Streptospondylus altdorfensis, Megalosauroids and Allosauroids, were most likely transported from the nearby Armorican Massif before settling on the muddy seafloor highlighting the faunal exchange between Boreal and Tethyan provinces at the time. These fossils, often isolated or fragmentary, frequently bear evidence of prolonged exposure, including encrusting oysters and serpulid worms, reflecting the complex taphonomic processes or the the biological, chemical, and physical events that happen to an organism's remains after death, affecting their preservation until they are found or fossilised in this low-energy marine environment.
For travellers fascinated by the natural world, the Vaches Noires vliffs along Normandy’s coast offer an unforgettable journey into deep-time history. At low tide, the foreshore reveals fossils ranging from ammonites and belemnites to marine reptiles and even occasional dinosaur remains, brought to light by the relentless action of waves and winter storms. While access to the cliffs themselves is limited for safety and conservation reasons, guided tours provide a captivating way to experience this dramatic landscape, and the Paléospace Museum in Villers-sur-Mer brings the story of the Jurassic seas to life.