3-D Thermokinematic Restoration of the Eastern Cordillera and Foothill of Colombia, and Paleogeographies Prediction

Abstract

A common limitation in exploration and production of hydrocarbon targets in compressional settings is that the present day, post-kinematic, distribution of petroleum elements (e.g. source rock, reservoir fairways) are unlikely to represent their syn-depositional configuration. They are likely to have been translated during deformation, laterally segmented with oblique structures and had significant elevation changes especially if they are captured within frontal limb deformation. We present a workflow that addresses these factors by incorporating palaeodepositional architecture and thermochronology data into a kinematic model. This study presents a 3D sequential restoration of a portion of the Eastern Cordillera of Colombia and the Foothill. The study area covers approximately 200 km along the strike direction, and approximately 120 km in dip direction from the axial zone of the Eastern Cordillera to the Foothills. Nine evolutionary stages, from 65 Ma to the Present-Day, are considered in this study. Several fold-and-thrust-belt evolutionary histories have been unraveled by means of the growth strata analysis. In deepwater settings where sedimentation rates are often higher that rates of erosion resulting in burial of structures. However, in subareal belts the erosional rate is likely to be higher than the depositional one; such as is the case in the Eastern Cordillera. In this inverted belt where the growth strata is mostly eroded, we use thermochronological techniques to constrain the sequential structural evolution. Thermochronometric data from apatie fission track (AFT) and zircon helium (ZHe) were available for this investigation. Other indirect tectonic-dating indicators such as paleoprovenance, paleocurrents, and paleoelevation were also used to understand the structural evolution in a comprehensive manner. This technique also permit a better understanding of the kinematics and mechanisms involved in the fold belt formation, thereby allowing us to quantify the rate of folding, thrusting and uplift. Additionally, after every restoration stage the ‘kinematic vectors’ that reflect the spatial variation through time are used to predict paleogeographies in which stratigraphic facies are restored to their syn-depositional location. By applying this integrated approach we can constrain the lateral distribution of source rock and reservoir fairways within a complex structural setting, thereby reducing uncertainly in both exploration and production phases.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016