The structure of the SW part of the Cantabrian Mountains

The present map is the continuation of the map published by De Sitter in 1962. The folded Precambrian basement in this area is overlain unconformably by Cambrian up to Carboniferous strata. The Palaeozoic has been uplifted during the Bretonic phase, and folded during the Sudetic, Asturian, and Saalic phases. In the western end of the Leónides the structures known from the eastern part of the Luna unit do not continue but are replaced bij one syncline and a number of thrusts. Major block faulting of the basement determined the curved structure of the ""Asturian Knee"" and also the diverse contemporaneous directions of thrusting and folding. Thinly developed Devonian of the Caldas Formation demonstrates the presence of a structural ridge early during the sedimentation. Stephanian intramontane basins developed along faults in downwarped areas