Geodiversity Days 2026

THREE SLATE QUARRIES – THREE PURPOSES

From heritage to innovation: discover how the former slate quarries continue to shape our region. (FR / LB)

guided tour | organised by Musée de l'Ardoise, Haut-Martelange

• 10:00 - 13:00
• Meeting point: Musée de l'Ardoise
• Important : Sturdy footwear, weather-appropriate clothing 
• Reservation:  https://booking.mnhn.lu/fr-fr/offre-tous-publics/trois-ardoisieres-trois-vocations
• Extended programme: Paid descent into the underground chambers of the Slate Museum – self-guided tour of the Haut-Martelange site above ground
• Description: 

What becomes of a former slate quarry once mining ceases?

How can these sites, which bear witness to our industrial past, still play a role in our future?

To mark the Geodiversity Days, join us on a guided walk of around 6 km to discover three iconic former slate quarry sites, each illustrating a new way of showcasing this exceptional heritage.

The route begins at the Slate Museum, where this heritage is preserved, studied and passed on. It continues to the former Donner slate quarries in Martelange (Belgium), now at the heart of an ambitious pilot project for energy storage that harnesses the potential of the vast underground chambers. Finally, it leads to the Geo-Energy site in Martelange-Rombach, where the University of Luxembourg, in partnership with the Municipality of Rambrouch, is studying the potential of the subsoil to develop sustainable heating and cooling solutions for the future Rombach neighbourhood.

At each stage, a specialist will share their expertise:

• Jacques Windeshausen, owner and manager of the former Donner slate quarries;
• Dr Natascha Kuhlmann, geologist at the University of Luxembourg
• Doris Thilmany, managing director of the Slate Museum and a long-standing volunteer with the Friends of Slate (Amis de l’Ardoise asbl)

Throughout the walk, you will learn about the history of slate mining in the region and the links between these three sites. This walk will show you how a shared heritage can take very different forms today: preserving the memory of traditional craftsmanship, advancing scientific research and devising the energy solutions of tomorrow.

A unique opportunity to take a fresh look at these landscapes shaped by slate and to discover how heritage, geology and innovation can complement one another to build the future.

The Minette of Lorraine and Luxembourg – a geological treasure on the border (FR)

guided tour | organised by Minett Unesco Biosphere

• 14:00 - 16:00
• Meeting point: Parking at the end of Rue du Maréchal Joffre, F-54190 Villerupt
• Reservation: https://forms.zohopublic.eu/minettunescobiosphere/form/GeodiversityDay202603102614001600/formperma/IsQ6EArOA6389DV6myhs1ILRLeAaSQZ372HLvRCX4Wk

• Description:
  A tour of the former Micheville open-cast mine site, where ‘La Minette’ was mined until 1974. The 463-hectare site has since become a protected natural area that bears witness to our region’s industrial and geological past. Discover the geological features of this site in the company of the authors of the book La Minette de Lorraine et du Luxembourg – un trésor sur la frontière en 50 questions à des géologues and learn more about the rich biodiversity that has reclaimed this former mining site over the last 50 years.

Urban Fossils - Fossilien an der Stad  (Fossils in the city) (LU)
guided tour | Musée national d'histoire naturelle Luxembourg (MNHNL)

• 10:30 - 12:30 
• Meeting point: At the entrance of the Naturmusée (MNHNL)
• Reservation: [insert Link]
• Guide: Robert Weis (Geoscientist at MNHNL)
• Réservation: https://forms.zohopublic.eu/minettunescobiosphere/form/GeodiversityDay202603102614001600/formperma/IsQ6EArOA6389DV6myhs1ILRLeAaSQZ372HLvRCX4Wk

• Description :
  Fossil hunting in the city? The pavements, plinths and façades of Luxembourg City are strewn with the fossilised remains of extinct creatures. Embedded in the natural building blocks of the buildings, these urban fossils offer fascinating insights into 350 million years of Earth's history. Discover a diverse selection of 14 different and fascinating fossils on a walk from the National Museum of Natural History to the main railway station.

Traces of Life and Landscape at Héikraiz near Heffingen, Geotope of the Year 2026 (GER)

guided tour | Mëllerdall Nature and Geopark

• 14:00 – 17:00
• Departure: [INFO MISSING]
• Guide: Birgit Kausch (Head of the Geology Department)
• Booking: https://booking.mnhn.lu/fr-fr/offre-tous-publics/traces-de-vie-et-de-paysages-a-lheikraiz-pres-de-heffingen-geotope-de-lannee-2026-all

• Description:
  The area around Héikräiz is home to numerous traces of the past. On a 7.5 km walk, we’ll discover traces of 200 million years of Earth’s history on the plateau, 2 million years of the landscape’s history in the valleys, and traces of human land use all around us. A visit to the Loschbour site also brings the history of humankind in the region to life.

Conference and discussion: “Underground Tensions: The Challenges of Critical Raw Materials” (FR)

conference and discussion | organised by the Luxembourgish UNESCO Commission & Activize

• 18:00 - 19:30, doors open at 17:30
• Location: Naturmusée
• Reservation: https://booking.mnhn.lu/fr-fr/offre-tous-publics/conference-debat-sous-sols-en-tension-les-enjeux-des-matieres-premieres-critiques-fr
• Contact: contact@activize.site
• Free entry
• Description:
  To mark UNESCO’s International Day for Geodiversity, the Luxembourg National Commission for UNESCO and Activize are organising a strategic conference and debate focusing on critical raw materials and the potential of our subsoil in the face of the challenges posed by the energy transition.
  The Critical Raw Materials Act sets ambitious targets for Europe by 2030: 10 per cent extraction, 40 per cent processing and 25 per cent recycling within Europe. Against this backdrop, where do we actually stand? What resources lie beneath our feet in the Greater Region? And how can we reconcile a mining revival, industrial sovereignty and social acceptability?
  
  To answer these questions, we have brought together four leading experts:
  • Sophie Decrée and Christian Burlet, geologists at the Geological Survey of Belgium, who will provide an overview of mining exploration in Europe and new exploration techniques.
  • Robert Colbach, Director of the Luxembourg State Geological Survey, who will discuss the phase-out of fossil fuels and Luxembourg’s potential in the fields of geothermal energy and hydrogen.
  • Alexandre Nominé, a researcher at the University of Lorraine (Mines Nancy), who will address the challenges of substitution and the geopolitics of critical materials.

The conference will be followed by a round-table discussion open to the public and a networking session.