Plio-Quaternary vertical motion of the Northern Apennines: Insights from dynamic modeling

Abstract

We test the effects of different geodynamic mechanisms on the Pliocene to present-day dynamics, and in particular on the vertical motions, of the Northern Apennines system by means of two-dimensional finite element models. We show that the Pliocene features of the Northern Apennines (exhumation of deep rocks in western Italy and fast subsidence rates in the Adriatic foredeep) can be adequately reproduced by a model (SLAB) characterized by the passive sinking of a negatively buoyant Adriatic slab and by the upwelling of buoyant asthenosphere beneath western Italy. Model SLAB is, however, not able to account for the Quaternary and present-day pattern of vertical motion of eastern Italy and of the Adriatic basin. A deep configuration of the system characterized by a detached slab (model DETACH) may explain the vertical motions of these areas, constrained by uplift of the eastern portions of the Apenninic chain, by an eastward shift of the foredeep depocenter and by lower subsidence rates in the Adriatic basin. The tectonic and stratigraphic data showing major differences between the Tertiary and the Quaternary evolution of the Northern Apennines are discussed.