The Mesozoic extensional imprint on the Ebro foreland basin (NE Spain); insights from seismic and gravity data

The Ebro basin, in northeastern Spain, represents a Cenozoic foreland basin that underwent a complex previous tectonic evolution characterized by three important pre-orogenic stages; deformation related to the Variscan orogeny and two previous Mesozoic (Late Permian-Triassic and Late Jurassic–Early Cretaceous in age) rifting stages. We studied an area located within the Ebro foreland basin close to its southern margin and to the deformation front of the Iberian Chain. In this work, we integrate the interpretation of depth-converted seismic lines acquired in the 1970's with gravity data to infer the tectonic evolution of the study area during the Mesozoic and Cenozoic. The residual anomalies range from -3.5 to 2.5 mGal and shows several maxima elongated in a NW-SE direction coinciding with the orientation of normal faults deduced from the interpretation of available seismic lines. This work highlights the benefits of combining different techniques to better define foreland basin geometries at depth and inferring their deformational histories, fundamental to understand their subsidence evolution and/or thermal history.