Tectonic and climatic control on the Late Messinian sedimentary evolution of the Nijar Basin Nijar Basin (Betic Cordillera, Southern Spain)

The Late Messinian fill of the Nijar Basin (Betic Cordillera, southeastern Spain) mainly consists ofclastic deposits of the Feos Formation that at basin margins rest unconformably above the primaryevaporites of the Yesares Formation, the local equivalent of the Mediterranean Lower Gypsum. TheFeos Fm. records the upward transition towards non-marine environments before the abrupt returnto fully marine conditions at the base of the Pliocene. The Feos Fm. is clearly two-phase, with ‘lower’and ‘upper’ members, which exhibit substantial differences in terms of facies, thickness, depositionaltrends and cyclical organization. These members record two distinct sedimentary and tectonic stagesof Nijar Basin infilling. A high-resolution, physical-stratigraphic framework is proposed based onkey beds and stratigraphic cyclicity and patterns that differ largely from those of most previouslypublished studies. The predominant influence on stratigraphic cyclicity is interpreted to be precessionallydriven climate changes, allowing their correlation to the Late Messinian astronomicallycalibrated chronostratigraphic framework. Detailed correlations suggest a phase of enhanced tectonicactivity, possibly related to the Serrata-Carboneras strike-slip fault zone, during the first stage(‘lower’ member), resulting in a strongly articulated topography with structural lows and highscontrolling sediment thickness and facies variation. Tectonic activity decreased during the secondstage (‘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. Faciescharacteristics, overall stacking patterns and depositional trends of the Feos Fm. are analogous withuppermost Messinian successions of the Northern Apennines, Piedmont Basin and Calabria. Despiteminor differences related to the local geodynamic setting, these basins experienced a common LateMessinian history that supports the development of a single, large Mediterranean water bodycharacterized by high-frequency, climatically-driven changes in sediment flux and base-level.