Resumen
The integration of surface, subsurface and paleomagnetic data allows the 3D reconstructionof the geometry of the northern border of the Cameros basin for its extensional, pre-inverted stage. Inthe model proposed, the Cameros basin represents a lens-shaped, large-scale growth syncline over amajor basement fault with maximum thickness of deposits of about 8000 m in its depocenter, graduallydiminishing toward the north and south. A series of analogue models validate this geometry, pointingto the role of interlayered detachment levels on the development of syncline-basin geometries.