Note sur le Bassin Houiller de Cinera-Matallana

In the north of Spain, in the province of León, in the neighbourhood of Ciñera and Matallana, a limnic coalbasin extends between the rivers Rio Curueño and Rio Bernesga, with a E—W strike of the layers. This coalbasin, the length of which is 15 km and which is not more than 5 km wide, follows a direction, which is E—W parallel to the Cantabrian Mountainrange. The deposit, which have a regular tectonical aspect on the north side, become more complicated on the south side and especially in the eastern part. The structure of the basin is an asymmetric synclinorium. The axial plane is nearer the southern part of the basin. The dip-slopes in the north flank are less steep than those in the south flank, where the layers overkeep to the north in some places. Rarely, a specific horizon runs through the basin without pinching out or without changing the composition of the sediment. The greater part of the layers of coal in exploitation are in the western part of the basin. The sedimentation began with the coarse grained conglomerates along the north side and especially the conglomerates at Correcillas in the N—E, the thickness of which is nearly 250 m. The age of the sediments is Stefanian B.