Resumen de Modelos de inversión positiva en sistemas de fallas normales en graderío: los márgenes de las cuencas extensionales cretácicas en la Cordillera Ibérica centro-oriental
Carlos Luis Liesa Carrera, José Luis Simón Gómez
Boundary faults in extensional settings are ussually formed by several associated fault planes showing a general step fault arranging in cross section. Several examples of Tertiary positive inversion of such Cretaceous normal fault systems in Las Parras and Calve subbasins (central-eastern IberianChain) are studied. These examples and other field observations allow us to define three different models of positive inversion. In model 1, the external fault is reactivated as reverse, whereas theinner faults remain inactive in the hanging wall of the thrust and show their original normal offset.In model 2, the reactivated fault is located in the inner part, whereas the external faults remain asnormal faults in the footwall of the thrust so formed. In model 3, the normal fault system is only reactivated in the deep segment and a short-cut is created cutting its footwall; The thrust surface outcroping far away from the extensional fault traces. In all cases normal faults can be verticalized,rotated or folded as deformation of the thrust sheet or the footwall occurs.
