DIVIDE AND HIGHEST MOUNTAINS VS SUBDUCTION IN THE APENNINES

Abstract

We present data related to the water divide of the Apennines, and its relation to the highest mountains. Frequently, the highest mountains do not coincide with the divide, but they are rather locat­ed toward the foreland to the 'east'. This is interpreted as induced by the faster 'eastward' propagating tectonic wave generated by the retreat of the Apennines subduction zone during Pliocene and Quaternary times (10-30 mm/a) with respect to average denudation rates ( <1 mm/a). The vertical and horizontal offset of the highest mountains with respect to the divide indicate tectonics are general­ly faster than denudation rate when subduction rolls back in a steady state, and lithologies of the outcropping belt are fairly homogeneous. The slowing of the subduction, shaly lithologies in the 'eastern' foreland slope, and transfer zones may instead deter­mine an offset of the highest mountains with respect to the divide toward the hinterland to the 'west'. [...]