NEOGENE SEDIMENTATION AND TECTONIC‐EUSTATIC CONTROL OF THE MALAGA BASIN, SOUTH SPAIN

Cenozoic sediments in the Málaga area range from the lower Miocene or uppermost Oligocene to the Quaternary. Tortonian (late Miocene) ‐ Quaternary sediments correspond to the fill of the Málaga Basin. Older sediments were laid down before the basin had acquired its present‐day structure. A number of important stratigraphic discontinuities are present within the Cenozoic succession. In the late Oligocene‐early Miocene, sandy sediments and conglomerates assigned to the Alozaina Formation, derived from the basement Malaguide Complex, were deposited in shallow‐marine conditions contemporaneously with deformation in the Internal Zones of the Betic Cordillera. The overlying transgressive Viñuela Formation (late Aquitanian‐early Burdigalian) was deposited in deep‐marine conditions which extended over a somewhat wider area than that occupied by the Málaga Basin. Sedimentation was dominated by classical turbidity currents and high‐density mass flows. Sediments of middle Miocene age are absent. Marine sedimentation resumed in the Tortonian as a consequence of a eustatic sea‐level rise. There was clear tectonic control on the depositional system as indicated both by the occurrence of coarse‐grained detritic sediments, which impeded the development of a bioclastic (carbonate) shelf, and also by the formation of a prominent unconformity. NW‐SE and NE‐SW trending faults, defining subsiding areas and highs, controlled the pattern of sedimentation. Strike‐slip activity on these faults (right‐ and left‐lateral, respectively) was relatively minor compared to dip‐slip activity; normal faults with throws of up to 1 km are known, and result from approximately east‐west extension. The Tortonian succession is overlain unconformably by Pliocene marine deposits which were deposited during an abrupt transgression. Post‐Pliocene sedimentation has been largely continental.