Ricerc@Sapienza

Structural analysis and Anisotropy of Magnetic Susceptibility are here applied to the fault zone (several hundreds of meters thick) associated with an E-W striking, 20 km-long segment of the Vallès-Penedès Fault (Catalan Coastal Ranges). The results obtained indicate a complex structure, mainly resulting from the imprint of Paleogene compressional events on a fabric inherited from the Variscan orogeny, and its Late-Variscan and Mesozoic extensional history. The prevailing foliation on the fault gouge and microbreccia is oblique (striking NW-SE) to the main E-W trace of the fault.

Anisotropy of magnetic susceptibility (AMS) has been applied to the study of shallow fault zones, although interpretation of the results requires establishing clear relationships between petrofabric and magnetic features, magnetic behaviour of fault rocks, and an extensive knowledge of P-T conditions. In this work, we demonstrate that magnetic methods can be applied to the study of heterogeneous fault zones, provided that a series of requisites are met.