Slab length and slab tearing control asymmetric exhumation of the Calabrian Arc

Abstract

Slab dynamics play a fundamental role in shaping landscapes through subduction, tearing, and rollback. The Calabrian Arc, situated along the convergent margin of the Eurasian and African plates, offers a natural laboratory to investigate the interplay between slab rollback, geometry, and tearing. Building upon prior studies that primarily focused on large-scale geophysical or tectonic data, our study synthesizes previously published low-temperature thermochronology datasets to reinterpret the long-term evolution of the Calabrian Arc using new thermal modeling. Our integrated analysis reveals a cessation of rapid exhumation earlier in the north (∼14 Ma) relative to the south (∼9 Ma). Differences in the timing of exhumation slowdown are interpreted to reflect the geodynamic effects of the diachronous arrival of the Ionian slab at the 660 km mantle transition zone, the extended northern slab reaching the transition zone earlier than the shorter slab segment in the south. A slab tear in the Catanzaro trough delimits the boundary between the longer and the shorter slab segments and provides further evidence supporting this model. This study provides an explanation for the asymmetrical exhumation of the Calabrian Arc, emphasizing the role of heterogeneous slab length and tearing dynamics in the shaping of tectonic patterns within subduction zones.