Azimuthal transects of stream orientations: an advance in understanding the regional morphotectonic setting of eastern Abruzzo (Central Italy)

Abstract

The recently proposed azimuthal transects method was applied to the drainage network of the eastern Abruzzo area, in order to confirm the location and identify the kinematics of regional fault zones, supposed to characterise the boundaries between different morphotectonic sectors previously recognised in the area. This methodology consists of applying the azimuthal analysis of low order (younger) stream orientations along transects crossing inferred faults. Its usefulness in morphotectonic investigations is linked to the possibility of identify statistical progressive rotations of channels induced by strike-slip displacements, especially where the classical structural analysis is unlikely to be performed because of lacking pervasive deformations within outcropping rocks. At the boundaries between the three different morphotectonic sectors formerly mentioned, strike-slip offsets were identified along E-W oriented fault zones, whose presence is also suggested by some macroscopic geomorphological evidence, such as the deflection of several main rivers towards the E-W direction. These results are consistent with those get by structural and geophysical studies, thus allowing to infer that these shallow crust plio-quaternary deformations could be the effect of the activity of the E-W lithospheric deformation zone which, according to many Authors, would divide the Adriatic plate into two different portions.