Durbuy Anticline

The Durbuy Anticline provides a textbook example of a cross-section through an anticline, widely employed for scientific and educational purposes since the early 19th century. This wonderfully exposed outcrop is also known as l’Anticlinal d’Omalius after the famous Jean-Baptiste-Julien d’Omalius d’Halloy (the Father of Belgian Geology, known from the clay-mineral halloysite) who described it in 1807. This description was part of a much larger endeavor: in 1813 d’Omalius completed the first geological map of France and bordering areas, which was published only in 1822 due to the political turmoil in western Europe. He divided the northern geological terrains into three parts, which subsequently through the works of Roderick Murchison and others, became well-established as the Silurian, Devonian and Carboniferous.The geosite in the medieval town of Durbuy boasts a base of 90 meters and a height of 37 meters and is composed of about 25 layers of Mid-Frasnian marine limestone of the Philippeville Formation. The slightly faulted anticline is an excellent example of Late Carboniferous Variscan deformation in Europe. The structure was carved out by the Ourthe River, which originally meandered on a Cenozoic sandy substratum, and is now eroding underlying Devonian formations without distinction of their hardness.