Quantifying long-term vs short-term uplift and exhumation of the Calabrian Arc - insights into the underlying driving mechanisms

Distinguishing the drivers that control mountain building, such as tectonic, climatic, and geodynamic forces of rock uplift at different time scales, forms the basis to understand landscape evolution through time.

In this study, we quantify the Cenozoic rock uplift and landscape evolution of the Calabrian Arc, located above the subducting Ionian-oceanic lithosphere in Southern Italy. Here, the Cenozoic rock uplift history has been strongly influenced by the retreat of the Ionian slab southwards, in which the Calabro-Ionian subduction zone shows a roll-back process that has been ongoing since Paleogene times. Some authors have linked rock uplift in the Calabrian arc to (i) tearing of the slab and subsequent toroidal mantle circulation, followed by vertical motion triggered by the detachment of the Ionian slab as a product of elastic rebound, controlling the last exhumation episodes followed by rapid uplift rates in the southern section of the Calabrian arc. (ii) In contrast, others argue that the vertical motion of the slab could also be related to mantle dynamics caused by roll-back inducing mantle upwelling around the Ionian slab edge. (iii) Third, based on thermochronological data, it has been claimed that base-level changes produced by climate change influence the last stage of exhumation. In order to evaluate the possible role of the different driving forces, we present a new compilation of the long-term (low-temperature thermochronology) and short-term uplift and exhumation data (uplift terraces-derived) in combination with new geomorphological data. We focus on three different tectonic blocks (Sila Massif, Serre-Aspromonte Massif and Peloritani Mountains), where the exhumation rates varied from north to south, with the highest long-term exhumation rates to the south (~1 km/Ma). The data is supported by the geomorphological analysis, which agrees with high values of Ksn mean (>250)  in the south and central section but contradicts the surprisingly high Ksn mean values (>250) in the north section. We discuss the landscape history on the long-short term and the possible geodynamic factors that could control the evolution of the Calabrian arc.