Tectonic and subsidence history of the Llanos foreland basin of Colombia

Colombia is located in the northwestern corner of South America. The NE-trending Andean mountain range is divided into three separate cordilleras: the Oriental (eastern), Central, and Occidental (western). The uplift of these cordilleras was caused by the combination of east-west shortening due to the subduction of the Nazca and Caribbean plates beneath the South American plate and the collision of the Panama arc-indentor with western Colombia. Between the Guiana Shield and the Cordillera Oriental, the basement dips westward into the subandean Putumayo and Llanos basins, which are separated by the Serrania de la Macarena and the Vaupes arch. The Arauca arch separates the Colombian Llanos basin from the Venezuelan Barinas-Apure basin. The Llanos basin of Colombia covers approximately 194,000 km2 and is considered one of the most prolific hydrocarbon basins along the eastern flank of the Andes in South America (ANH, 2007). The most significant factor affecting the hydrocarbon potential of the Llanos basin was the deposition of marine Cretaceous source rocks that were deeply buried and thermally matured (Moretti et al., 2009), and the multiple phases of orogeny (Parra et al., 2009b, 2010) that produced many structural and stratigraphic traps and pathways for oil migration.