Colombian Eastern Cordillera Different Models of Structure and Evolution: Implications in the Petroleum Systems and Palinspastic Restorations

Teson, Eliseo¹; Mora, Andrés; Namson, Jay; Ramirez Arias, Juan Carlos; and Navas Guzmán, Gustavo
¹[email protected]

Different tectonic models make strong impacts on the original basin configuration of an oil producing region. For example, high tectonic shortening is linked to bigger oil kitchens compared with areas of limited shortening. In addition, a strike slip component, if significant, make additional complications and change the basin configuration because of the effect of lateral movements. The use of one or the other models dramatically increases or decreases the exploration potential of an area. In this study we illustrate the influence of tectonic style and the evolution of a mountain chain by using the example of the Eastern Cordillera of Colombia, for which different structural models have been proposed. Some of these models propose very large tectonic shortening (Roeder & Chamberlain, 1995) while others pose much more limited tectonic shortening (Cooper et al., 1995, Kammer & Mora, 1999, Tesón et al., 2013). Similarly, the role of strike slip tectonics in the Eastern Cordillera has traditionally been a matter of debate. Here we show a summary of the proposed models with the most important implications of each. Finally, based on the analysis of maps, seismic sections and new balanced cross sections, we propose our own model illustrated by several structural reconstructions. This model, which proposes a lower amount of allochtony and limited strike slip component along the Eastern Cordillera, has important implications for the petroleum systems of the Caguán-Putumayo, Upper Magdalena, Eastern Cordillera, eastern foothills and Llanos basins. According to our model, correlations of oil versus source rocks are more straightforward and lateral facies tracks are easier to follow. On the other hand, the potential amounts of generated hydrocarbons are lower than the proposed by previous models.

AAPG Search and Discovery Article #90166©2013 AAPG International Conference & Exhibition, Cartagena, Colombia, 8-11 September 2013