Geowissenschaftliche Seminare

am Fachbereich Umwelt & Biodiversität (Abteilung Geologie)

Vorträge von Bachelorstudent:innen, Masterstudierenden und Doktorant:innen der geowissenschaftlichen Abteilung über ihre Forschungsprojekte mit anschließender Diskussion.

Die Seminare finden im Winter- und Sommersemester statt. Jeder ist willkommen!

Tracking lateral slab tearing through exhumation signal in the Calabrian Arc, Southern Italy

Nicolas Villamizar

(Ergebnisse seiner Doktorarbeit)

Throughout the Cenozoic, the rock uplift of the Calabrian subduction zone has been strongly influenced by the rollback and retreat of the Ionian slab since Paleogene times. This complex geological setting results from diverse geodynamic processes, including active extension, mantle dynamics, and the potential influence of slab tearing contributing to the uplift of the Calabrian Arc. Within this framework, the Coastal Chain in the Calabrian Arc stands out morphologically, with a long North-South trending mountain range of about ~75 km, aligned parallel to the subduction zone. New tomographic studies (Scarfì et al., 2018) depict a southward opening tear fault since ca.2 Ma, leading to rapid opening of the Marsili Basin. However, tracking the spatiotemporal surface response to horizontal tearing is challenging as several factors, such as overprinting tectonic events, deformation, or even a tectonic heritage on the upper crust, contribute to noise in the surficial response and the exhumation signal. In one of the narrowest subduction zones in the Mediterranean, with about 280km of extension.

Here, we used apatite (U-Th)/He dating to investigate the cooling history of the Coastal Chain in North Calabria, aiming to constrain the timing and rates of exhumation along the entire Chain. Our results reveal a spatially distinct pattern with ages progressively getting older from South to North from 2 to 8 Ma. We interpret our result of laterally migrating exhumation as a consequence of slab tearing at depth. It leads to isostatic rebound and thus exhumation of the upper plate. we argue our results document one of the only examples of spatial-time tracking of lateral-slab tearing in a natural system.