Deciphering complex lithospheric processes driven by slab rollback mantle flows
across the Siciliy Channel Rift Zone
PI: E. Attias (UTIG)
co-PIs: T. Becker (JSG), M. K. Sen (JSG), S. Naif (Georgia Tech)
In collaboration with the CREAK proposal submitted by M. Agius (Univ. of Malta) to the European Research Council on December 2023
Tectonic-driven passive rifting and mantle plume-driven active rifting are two mechanisms frequently invoked as the cause of continental breakups. Both mechanisms result in thermo-mechanical erosion of the lithosphere, which leads to thinning and rupture of the plate. Rifting in melt-poor and complex tectonic settings (i.e., at the boundary between subduction and rift margins) is poorly constrained. Studying rifting in such settings is essential to understanding the role of individual and multiparametric mechanisms in the overall rifting process. For example, the toroidal mantle flows around the edge of a subducting slab, and its influence on the adjacent continental plate is characterized by cascading processes that may lead to incipient continental breakup and new spreading rifts. Such a complex tectonic setting exists across the Sicily Channel Rift Zone (SCRZ). However, marine observations are limited to constraining SCRZ’s mantle flows and their effect on the overlying lithosphere.
What do we know about SCRZ from existing shallow datasets?
Evidence for crustal dynamics from intraplate and subduction-related volcanism (Faccenna et al., 2005), compression/extension (Devoti et al., 2011; Bahrouni et al., 2020), heat flow (Fuchs et al., 2021), seismic azimuthal/radial anisotropy and crustal thickness (Agius et al., 2022).
What do we know about SCRZ from existing deep datasets?
Evidence for upper mantle flow due to dynamic slab. Shear velocity structure at 100~km depth adopted from El-Sharkawy et al., (2020), shear-wave splitting from Barruol et al., (2009), and seismic surface-wave radial and azimuthal anisotropy data from Agius et al., (2022).
The ROTATOR project aims to understand the role of complex tectonics on continental breakups. We will collect passive and active marine EM, seismic, magnetic, oceanographic, and biogeochemical datasets at SCRZ to combine with analogue and numerical geodynamic models. Studying SCRZ’s intricate tectonics can promote our knowledge of when/why plate tectonics developed on Earth, the different processes that govern regional volcanism, and how critical elements circulate within Earth over broad spatiotemporal scales.
ROTATOR experiment: Deplyoment of 30 OBEMs augmanting CREAK's MT and OBS sites, and performing a CSEM survey (six towlines).