Basin modelling across the emergent Lesser Antilles island arc, SE Caribbean and impact on petroleum systems

We performed forward basin modelling along a profile in the south-eastern Caribbean to evaluate the effect of an evolving island arc on the evolution of petroleum systems in adjacent sedimentary basins. The geological model used is a published interpretation of a NW-SE regional 2D seismic line across the Lesser Antilles island arc, in which the Grenada and Tobago basins are interpreted as a single large basin during the Eocene that was split by the developing Lesser Antilles arc, north of the Caribbean-South America collision zone, during the middle Miocene. South of the collision zone, the eastern offshore Trinidad region has developed as a foreland basin since the middle Miocene. Basin modelling shows that formation of the Lesser Antilles arc caused an increase in temperature that subsequently decayed in space and time. Heating had a major impact on the maturation of Palaeogene source rocks adjacent to the arc, which became mature and over-mature. The heating also affected reservoir rocks that were deposited before and during arc formation, but not after the arc was formed. No temperature effects are observed in the eastern offshore Trinidad–Columbus Basin region.