The extent of penetrative Pyrenean deformation in the Ebro foreland Basin: magnetic fabric data from the eastern sector

Abstract

We studied Cenozoic sedimentary rocks in the NE Ebro foreland Basin using the Anisotropy of Magnetic Susceptibility (AMS) as a proxy for grain preferred orientation. Our new data, in combination with existing results, reveal that penetrative strain by layer-parallel shortening extends well beyond the Pyrenean thrust-wedge front into the Ebro foreland Basin, challenging the concept of the location of “deformation front” in the Southern Pyrenees. Penetrative strain, as revealed by the magnetic fabrics, seems to reach larger distances into the Ebro foreland Basin where stiffer layers constitute the main detachment level, whereas to the East strain dissipates closer to the deformation front when the detachment is mostly due to salt deposits.