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1 EXGEO-CGG, Maracaibo, Venezuela (e-mail: jeacol{at}hotmail.com)
2 Department of Earth Science and Engineering, Imperial College, Royal School of Mines, , Prince Consort Road, London SW7 2BP, UK
3 Ingeominas, , Diagonal 53# 34-53, Bogotá, Colombia
The Colombian Andes are characterized by a dominant NE structural trend, which is offset by ENE-trending right-lateral and NW-trending left-lateral structures. NE-trending faults are either dip-slip or oblique thrusts, generated as a result of a trans-pressive regime active since at least Palaeogene times. NW-trending faults are considered to be reactivated pre-Cretaceous extensional structures. Right-lateral shear on ENE-trending faults has resulted from oblique convergence between the Nazca Plate and the Northern Andes. Major changes in the geometry of the oblique-plate convergence between the Nazca and South American plates have generated the northward escape of the Northern Andes and stress-strain partitioning within the mountain belt. These strike-slip structures have exerted important controls on sedimentation, source-rock distribution, fluid flow and ore mineralization during Cenozoic times. The interpretation of the Northern Andes as a mountain belt affected by strike-slip deformation provides a structural context in which to reassess the exploration plays.