RESTREPO-PACE, PEDRO A., Conoco Colombia Inc., Houston,TX, FABIO COLMENARES, CAMILO HIGUERA, MARCELA MAYORGA, Geosearch Ltda. Bogota, Colombia, and JAIRO LEAL,Texaco Colombia, Bogota, Colombia

Abstract: Fold and Thrust Belt Along the Western Flank of the Eastern Cordillera of Colombia : Style, Kinematics and Timing Constraints Derived from Seismic Data and Detailed Surface Mapping

The west verging fold and thrust belt along the western flank of the Eastern Cordillera consists of a complex thin-skinned belt which resulted from polyphase deformation. Field data point to the initial development of a forward breaking thin-skinned thrust system consisting of west verging high frequency spaced imbricate thrusts. The youngest sediments involved in this system are Paleocene age together with Early Eocene (?) synkinematic deposits, and the thrusts are concealed below the Late Eocene unconformity. Subsequent reactivation of some of these structures occurred in a break backward sequence that initiated in Mid-Late Miocene time, as evidenced by the tilting of the Lower Eocene synkinematic deposits and from onlapping relationships within the Miocene fluvial/molassic deposits. This latter thrusting generated frontal intracutaneous wedges and hinterland west verging lower frequency spaced thrusts. Structural development concluded with major inversion of fundamental hinterland faults creating the present structural relief. Retrodeformed cross-sections indicate that at least 50% contraction took place here.We preset data that has profound implications in source rock burial-maturation- migration-charge and trap integrity for this highly prospective area.

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England