The effects of late Alpine tectonics in the morphology of the Argentera Massif (Western Alps, Italy-France)

Several swath profiles, drainage morphometric parameters, slope and drainage density maps were obtained by DTM analysis of the Argentera Massif (Western Alps). The spatial distribution of the analysed parameters indicates that the central-southern sector is characterized by orographic and drainage characteristics very different from the rest of the Massif. Two main systems of NW- and WNW-trending faults, the Orgials Fault and Valletta Fault, bound this area. Both faults belong to large-scale fault zones: the dextral strike-slip Bersezio Fault and the south-facing Colle del Sabbione thrust. The orientations and kinematics of both faults indicate a late Alpine (Pliocene to recent) SW-verging thrusting coupled with a dextral strike-slip movement. The central-southern sector of the Massif corresponds to the hanging wall of a SW-verging late Alpine thrust zone, and underwent the highest post Pliocene tectonic uplift in the Argentera Massif. The uplift occurred in a transpressive setting with an N-S shortening direction, which is consistent with the post-Pliocene tectonics in the southern portion of the Western Alps. (C) 2002 Elsevier Science Ltd and INQUA. All rights reserved.