Influencia de la tectónica de fractura y del diaprismo en la sedimentación del Jurásico y Cretácico basal al sur de la provincia de Jaén (zona subbética)

Resum

The relation between the Jurassic-basal Cretaceous sedimentation and the structural evolution of the Ventisquero-Sierra del Trigo tectonic unit is analyzed, emphasizing the influence of Keuper salt halokinesis. In the quoted tectonic unit materials from two different palaeogeographic realms outcrop. They belong to the External and Median Subbetic, which in other Subbetic areas are usually tectonically individualized. The abundance of coarse grained resedimented materials (slumps and conglomerates), the inferred dip of paleoslopes and paleocurrents and their areal coincidence with Keuper diapirs, lead us to conclude a genetic relation between the salt structures and the resedimentation processes. The Jurassic subsidence relative evolution is analyzed from isopach maps. The subsidence was controlled by hercinian fractures striking N60E and N-S, reactivated respectively during the Domerian-Early Bajocian and the Late Bathonian-Oxfordian. During the rest of the Jurassic times the Triassic salt tectonic determined the position of the areas with lowest subsidence rates. The salt structures evolved along the Jurassic from irregular anticlines, to pillows and eventually to diapirs towards the Jurassic-Cretaceous transition.