The area known as Les muntanyes russes de Sant Vicenç de Castellet, so the roller coaster of Sant Vicenç de Castellet, is a badland, one eroded surface with almost no soil and scarce plants on marine bluish mudstones that belong to member Igualada of geological formation Santa Maria, from period Eocene. It spreads roughly 5 Has in west slope of hill of Castellet. The phenomenon is caused by the coincidence in a slope of one soft, incoherent, easy to erode material, sporadic heavy rains and likely also a wrong human action –cut of pines, try of crop, over graze…- that opened the first injury in soil kicking off the self-accelerated erosion process. The result is a geological landscape of crests and valleys with a fractal beauty that reproduces in affordable space what would be the ranges and basins at continental scale.
Usually crowned pillars or witch’s chemneys develop in badlands when a compact rock, often sandstone, protects the soft ground beneath as a hat.
Despite the extremely poor soil of badlands, Aleppo pines (Pinus halepensis) succeed to root and survive in the summits and bottoms of this particular orography where a few centimetres of soil can be retained. Nevertheless this is not a true forest; there are almost no more plants out of pines.
Badlands on bluish o grey mudstones as the roller coaster of Sant Vicenç de Castellet are found in neighbour locations of Castellgalí and Marganell, nearby Igualada in district of Anoia and in Vic in district of Osona as well. They’re much common and wider in the inland of depression of Ebro on continental mudstones; the best known badland area is Las Bardenas Reales, near Tudela in district La Ribera, in Navarra.
[photos Jordi Badia]