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Tectonic and climatic control on the L ate M essinian sedimentary evolution of the N ijar B asin ( B etic C ordillera, S outhern S pain)
Author(s) -
Omodeo Salé Silvia,
Gennari Rocco,
Lugli Stefano,
Manzi Vinicio,
Roveri Marco
Publication year - 2012
Publication title -
basin research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.522
H-Index - 83
eISSN - 1365-2117
pISSN - 0950-091X
DOI - 10.1111/j.1365-2117.2011.00527.x
Subject(s) - geology , sedimentary depositional environment , tectonics , facies , sedimentary rock , structural basin , paleontology , geochemistry
The L ate M essinian fill of the N ijar B asin ( B etic C ordillera, southeastern S pain) mainly consists of clastic deposits of the F eos F ormation that at basin margins rest unconformably above the primary evaporites of the Y esares F ormation, the local equivalent of the M editerranean L ower G ypsum. The F eos Fm. records the upward transition towards non‐marine environments before the abrupt return to fully marine conditions at the base of the P liocene. The F eos 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 of N ijar B asin 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 the L ate M essinian astronomically calibrated chronostratigraphic framework. Detailed correlations suggest a phase of enhanced tectonic activity, possibly related to the S errata‐ C arboneras 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 the F eos Fm. are analogous with uppermost M essinian successions of the N orthern A pennines, P iedmont B asin and C alabria. Despite minor differences related to the local geodynamic setting, these basins experienced a common L ate M essinian history that supports the development of a single, large M editerranean water body characterized by high‐frequency, climatically‐driven changes in sediment flux and base‐level.