Photograph of the month

摘要

Roofing slate quarrying of global importance is carried out in the Upper Ordovician rocks of the Westasturian-Leonese zone of the Iberian Variscan belt. Several orders of folds with an associated cleavage developed during the first regional deformation phase. The photograph (view looking SE) shows an anticline-syncline pair developed in a multilayer made up dominantly of slates with thin intercalations of siltstones and fine grained sandstones deformed by parasitic folds with wavelengths of 10-20 cm.