STRUCTURE OF THE SIERRA DE CANTABRIA (SOUTHERN PYRENEAN FRONTAL THRUST, BASQUE COUNTRY, SPAIN) - A NEW PERSPECTIVE FROM SECTION BALANCING

The Sierra de Cantabria is a narrow belt of folded and thrusted Mesozo ic rocks along which the Basque-Cantabrian Basin is thrust southwards onto the Ebro Tertiary Basin. it has been regarded as the western exte nsion of the South-Pyrenean Frontal Thrust. Its architecture has tradi tionally been considered as a complex anticlinorium cored by great vol umes of Upper Triassic Keuper evaporites. However, a detailed structur al study in the Bernedo area (southern Basque Country) and the use of section balancing techniques enables us to constrain the geometry and composition of zones previously inaccessible to direct observation whe re Jurassic and Cretaceous rocks, instead of Triassic evaporites, are dominant.