NUMERICAL MODELS OF THE GEODYNAMICS OF ARC-CONTINENT COLLISION: INSIGHTS FOR UNDERSTANDING THE FORMATION OF HYDROCARBON-BEARING BASINS IN THE CARIBBEAN MARGIN OF COLOMBIA
Unravelling the geodynamic mechanisms behind basin formation in the Caribbean margin of Colombia (CMCB) is key for understanding petroleum systems in the region. The genesis of these Oligocene to present basins remains controversial as none of the proposed mechanisms of fore-arc extension, back-arc extension and block-rotation fully explain the formation of the basins in the CMCB. These mechanisms cannot explain basin formation because the following reasons: i) extension in the CMCB occurs in the absence of arc-magmatism, therefore there is not co-existent topography to load the lithosphere and allow the formation of fore-arc or foreland basins; ii) there is no evidence of a Paleocene-Eocene magmatic arc emplaced in the CMCB basement, which could trigger cooling-related gravitational collapse and generate lithospheric extension in the fore-arc or back-arc; and iii) the activity of the Romeral Fault Zone related to the oblique convergence of the Caribbean plate, and block-rotation and scape tectonics, ceases at middle Eocene times, before the onset of extension in the CMCB. Alternatively, the formation of these basins might be related to a Late Cretaceous arc-continent collision event driven by the convergence between the Caribbean and South America plates. In this project, I will use numerical visco-plastic mechanical models to test the hypothesis that the transference of the intra-oceanic arc to the overriding plate causes extension in the continental margin. This modelling will provide potential mechanisms for explaining the formation of basins in Northern Colombia and the Caribbean margin, some of which are the biggest hydrocarbon-bearing basins in the world.