Fault geometry, strain partitioning and deformation history inferred by fluvial topography and marine terraces analyses

Abstract

Advancements in the quantitative investigation of fluvial topography in tectonically active regions account for the emerging numerical modelling of river profiles and their linear inversions. Applications of a geomorphic approach strive for the reconstruction of long-term tectonic deformation histories by decoding base-level fall signals transiently embedded in the geomorphic record. I present integrated results from river profile inversions and marine terraces analyses, here used to outline the deformation model associated to a debated crustal fault system at the southern termination of the Calabrian Forearc High (Central Mediterranean). The study aims at constraining spatial and temporal variations in geometry, strain partitioning, slip rate, and time-transgressive propagation of the tectonic deformation associated with a fault system. In particular, I systematically analyze river profiles draining the eastern flank of the Peloritani Mts. in northeastern Sicily (southern Italy), a NNE-SSW-trending mountain ridge thought as located at the footwall of an active, ESE-dipping normal fault. I perform the linear inversions of fluvial topography by applying recently available MATLAB scripts, and I carry out the analysis of terraced surfaces by both GIS tools and MATLAB-based software packages. The results I obtain suggest that the eastern flank of the Peloritani Mts. have been deformed according to at least three main stages of uplift accommodated along distinct, ∼10–15 km-long en-échelon arranged fault segments. The reconstructed evolution of tectonic deformation unveils time-transgressive, southward propagation since the last ∼600 kyr, inset in a general increase, through time, of the regional component of uplift. The results of this study contribute to address the issues of the deformation style and strain partitioning along complex and/or debated fault systems. These results also demonstrate the potential of the geomorphic approach in defining the spatial and temporal tectonic evolutionary model of a region.