Coupling far and near tectonic signals in syn-orogenic sediments: the Olvena growth strata (Sierras Marginales, southern Pyrenees).

The Olvena area (Sierras Marginales, Southern Pyrenees) provides an outstanding example for studying the relationships between tectonics and sedimentation related to fold-and-thrust systems having shallow décollements. Stratigraphic and sedimentological analysis allows to infer the interference of Oligocene locally-sourced alluvial fans and a far-sourced wider fluvial system. Initially, uplift resulting from folding and thrusting precluded the entrance of the north-coming wider fluvial system and isolated a subsiding area filled by west-flowing alluvial fans sourced in the rejuvenated reliefs. Subsequently, these reliefs were subdued yielding sedimentation associated with the north-coming fluvial system. Sequential evolution and stratigraphic architecture evidence thrust emplacement chronology, including out-of-sequence structures and the influence of evaporite flow along thedécollement. Despite these syn-tectonic deposits are linked to the Ebro Basin deposition, its megasequential evolution differs from the general sequence, highlighting the importance of differentiating the influence of near-coming sedimentary systems when interpreting basin-scale sequence stratigraphy.