Structural style and evolution of the offshore portion of the Sinu Fold Belt (South Caribbean Deformed Belt) and adjacent part of the Colombian Basin

Abstract

The Sinu fold belt, located in northwestern Colombia, is the southwesternmost part of the South Caribbean Deformed Belt, which has been interpreted as an accretionary wedge resulting from the subduction of the Caribbean Plate under the South American Plate. The geological interpretation of 2D seismic surveys and bathymetric maps, with the aid of a few exploration wells, has been the basis to construct a structural map and several geological sections to illustrate the offshore part of the Sinu Fold Belt and the portion of the Colombian Basin adjacent to the belt. Their analysis has allowed us to characterize different structural styles (thrusts and related folds in the outer part of the belt, and normal faults and shale diapirs in the inner one), the timing of the structures, as well as the kinematic evolution from a Cretaceous-Paleocene extensional event responsible for the Colombian Basin structure to the Pliocene-Quaternary contractional event which caused the Sinu Fold Belt.