Project Title: Slab tearing, vertical tectonic motions, and the Miocene marine gateways across the Gibraltar Arc.

Supervisor: Daniel Garcia-Castellanos, Ivone Jimenez-Munt

Objectives: The closure of the marine gateways across the Gibraltar Arc during the Late Miocene caused massive salt accumulation in the Mediterranean basin during the Messinian salinity crisis (MSC). This major geographic change has been linked to the vertical motions associated to subduction between Iberia and Africa. The temporal and spatial development of these motions has fundamental implications for interpreting the MSC sedimentary record and its impact on the Mediterranean Sea. This project aims to quantitatively test the geodynamic validity of competing scenarios proposed for the geodynamics of both the Gibraltar Arc and the MSC, and to provide constraints on their timing. The PhD student will make use of fore-frontier numerical models of crustal and mantle deformation. The results will also allow the application of surface process models in the extreme geological conditions of the MSC. The project will build on recent data produced within the TopoIberia project (seismics, seismology, tomography, GPS) and the ITN MEDGATES.

Expected Results: 1) Constraints on the vertical motions associated with lithospheric processes in the Gibraltar Arc during late Miocene, using numerical modelling of slab deformation; 2) Quantitative understanding of the topographic changes in the Mediterranean-basin resulting from closure of the Atlantic-Mediterranean gateways; 3) Further constraints on the geodynamic processes involved in the MSC.

Academic secondment: UR1, Brun, 2 months, comparison of analogue and numerical models of slab tearing. UM, Gueydan, 1 month, synthesis of geodynamics of the Betics (Rennes)-Alboran Sea (Montpellier) system. Collaboration with S. Zlotnik, Politechnic University of Catalunia. Industry secondment: STATOIL, 2 months, hydrocarbon exploration strategies in subduction settings.

Links to other projects: Complementary to the numerical modelling of slab tear and its dynamic topographic effects (ESR1,3,4,7,13); Sharing of geophysical and geological data from the Alboran-Gibraltar Arc region with ESR 2,3,7,10.