Geology and karst landscapes of the Serranía de Cuenca

Limestone mountains

Almost the whole Serranía is limestone and dolostone from the Jurassic and Cretaceous, deposited on a sea floor and later raised into parameras, high, open limestone plateaux, or muelas, flat-topped limestone hills. Slightly acidic rainwater dissolves them: at the surface it creates karren and ruin-like landforms, the tormagales, such as the Ciudad Encantada, the “Enchanted City” rock formations, covering about 20 km², or the Callejones de Las Majadas; underground, caves and shafts, and through collapse, torcas, collapse sinkholes, and lakes. Rivers have cut the muelas into gorges with vertical walls, and lime-rich waters build tufa barriers.

Other rocks

The Sierra de Valdemeca and the rodenales of the south are made of Triassic red sandstone, rodeno, older than the limestone: at Collado Bajo, the mountain range’s summit, and in Boniches, with quartzite conglomerates. Folded layers can be seen in the gorges, such as the anticline at the Armentero viewpoint, and in Fuentes water dissolves gypsum and opens dolines in a few years: the latest in the River Moscas complex opened in 2009.

Fossils

There are dinosaurs in these rocks: Las Hoyas, from the Early Cretaceous, in La Cierva, and Lo Hueco, about 75 million years old, in Fuentes, uncovered by high-speed railway works in 2007. The Ruta de los Dinosaurios follows them.