Mid-depth calcareous contourites in the latest Cretaceous of Caravaca (Subbetic Zone, SE Spain). Origin and palaeohydrological significance

Abstract

Deep marine carbonates of Late Campanian to Early Maastrichtian age that crop out in the Subbetic Zone near Caravaca (SE Spain) contain a thick succession of dm-scale levels of calcareous contourites, alternating with fine-grained pelagites/ hemipelagites. These contourites, characterised by an abundance and variety of traction structures, internal erosive surfaces and inverse and normal grading at various scales, were interpreted as having been deposited under the influence of relatively deep ocean currents. Based on these contourites, a new facies model is proposed. The subsurface currents that generated the contourites of Caravaca were probably related to the broad circumglobal, equatorial current system, the strongest oceanic feature of Cretaceous times. These deposits were formed in the mid-depth (200–600 m), hemipelagic environments at the ancient southern margin of Iberia. This palaeogeographic setting was susceptible to the effects of these currents because of its position close to the narrowest oceanic passage, through which the broad equatorial current system flowed in the westernmost area of the Tethys Seaway. Regional uplift, related to the onset of convergence between Iberia and Africa, probably favoured the generation of the contourites during the Late Campanian to the Early Maastrichtian.