Tectonic and climatic control on theLateMessinian sedimentary evolution of theNijarBasin (BeticCordillera,SouthernSpain)

Abstract

AbstractTheLateMessinian fill of theNijarBasin (BeticCordillera, southeasternSpain) mainly consists of clastic deposits of theFeosFormation that at basin margins rest unconformably above the primary evaporites of theYesaresFormation, the local equivalent of theMediterraneanLowerGypsum. TheFeos Fm. records the upward transition towards non‐marine environments before the abrupt return to fully marine conditions at the base of thePliocene. TheFeos Fm. is clearly two‐phase, with ‘lower’and ‘upper’members, which exhibit substantial differences in terms of facies, thickness, depositional trends and cyclical organization. These members record two distinct sedimentary and tectonic stages ofNijarBasin infilling. A high‐resolution, physical‐stratigraphic framework is proposed based on key beds and stratigraphic cyclicity and patterns that differ largely from those of most previously published studies. The predominant influence on stratigraphic cyclicity is interpreted to be precessionally driven climate changes, allowing their correlation to theLateMessinian astronomically calibrated chronostratigraphic framework. Detailed correlations suggest a phase of enhanced tectonic activity, possibly related to theSerrata‐Carboneras strike‐slip fault zone, during the first stage (‘lower’member), resulting in a strongly articulated topography with structural lows and highs controlling sediment thickness and facies variation. Tectonic activity decreased during the second stage (‘upper’member), which is characterized by (1) a progressively dampened and homogenized, (2) overall relative base‐level rise and (3) gradual establishment of hypohaline environments. Facies characteristics, overall stacking patterns and depositional trends of theFeos Fm. are analogous with uppermostMessinian successions of theNorthernApennines,PiedmontBasin andCalabria. Despite minor differences related to the local geodynamic setting, these basins experienced a commonLateMessinian history that supports the development of a single, largeMediterranean water body characterized by high‐frequency, climatically‐driven changes in sediment flux and base‐level.