Late Quaternary uplift and valley evolution in the Northern Apennines-Lamone catchment.pdf

Quaternary International 101–102 (2003) 253–267 Late Quaternary uplift and valley evolution in the Northern Apennines: Lamone catchment Alessandro Simoni*, Carlo Elmi, Vincenzo Picotti Universit a di Bologna, Dipartimento di Scienze della Terra e Geologico-Ambientali, Via Zamboni, 67-40126 Bologna, Italy Abstract The topographic evolution of mountain chains is fundamentally dictated by the balance of erosional and tectonic processes. In the Northern Apennines, several questions about the late Holocene to present deformation style and uplift rates are still open. We consider a typical NE facing drainage basin, focusing on all the geomorphic markers capable of supplying direct or indirect information regarding tectonic forcing on the landscape. Characteristics of altitude and relief, drainage pattern, river profile and fluvial response expressions were found to be in good agreement, indicating that the most recent tectonic activity consists of a general persistent uplift of the chain, associated with an extensional regime, where different sectors are distinguished through differential uplift. Such differences have been found to act both along and transverse to the chain, causing similar coherent patterns of response in erosional processes. The geomorphology of the catchment displays several features, which together with the long sustained tectonic forcing indicate the near-attainment of a dynamic equilibrium between the rates of tectonic forcing and erosional processes, creating steady-state topography. r 2002 Elsevier Science Ltd and INQUA. All rights reserved. 1. Introduction The complex interactions between tectonics (the main factor controlling surface uplift) and denudational processes in mountain belts constitute the focus of many research efforts around the world. This renewed interest in traditional topics of landscape evolution is mainly due to the widespread availability of digital elevation models (DEMs) and the development of equations to describe erosion