Project Title: Subduction evolution of land-locked basins.

Project Supervisor: Jeroen van Hunen, Mark Allen

Objectives: This project aims to understand and constrain the evolution of land-locked basins by combining observables with dynamical models. Continental collision can trap land-locked oceanic basins (e.g. Mediterranean, South Caspian Basin), and their eventual subduction undergoes a complex tectonic evolution, with topography as a primary diagnostic. Objectives are: 1) To link observables (tectonics, seismics, folding, subsidence) with numerical models to identify key parameters influencing the initiation or re-establishment of subduction of land-locked basins; 2) These basins may have significant hydrocarbon potential, e.g. the very thick, folded, sedimentary sequences of the South-Caspian Basin. Subsidence and geotherm data of this region will be used as to constrain geomorphological-tectonic models for this young subduction system; 3) Once started, subduction of the basin is complex and variable, and possibly involves formation of back-arc basins, segmented plates, STEP faults, and local slab break-off. Combining tomographic, topographic, and volcanic data with model predictions will provide insight into the required conditions for each of those processes.

Expected Results: Quantitative models for 1) subduction (re-)initiation in land-locked basins, constrained by observables from the South Caspian Basin and the W-Mediterranean; 2) the role of the slow subduction-related subsidence and folding, and surface tectonics on the hydrocarbon potential of the South-Caspian Sea; 3) the role of basin size and age, and sediment supply on the basin tectonics; and 4) the conditions for eventual cessation of tectonics in the basins.

Academic secondment: Geosciences Rennes, Yamato; months 12-13: shallow tectonics models (e.g. folding). Industrial secondment: GRL, 2 months, linking geodynamical modelling to available reconstruction datasets

Links to other projects: Direct links with ESR1,2 through comparison of dynamic models with surface expressions, and ESR9,14 through modelling of continental collision.