GPS velocities and the construction of the Eastern Cordillera of the Colombian Andes

Abstract

AbstractGPS velocities across the northeast trending Eastern Cordillera of Colombia show oblique convergence at 8.8 ± 1.7 mm/yr, consisting of 8.0 ± 1.7 mm/yr of right‐lateral strike‐slip shear along the mountain range and 3.7 ± 0.3 mm/yr of northwest southeast shortening. Faster convergence occurs only at the northeast end of the Cordillera, where its eastern edge trends northwest and the highest mountains lie. The strike‐slip shear corroborates geologic work suggesting such movement southwest and northeast of the range. Given the ~200 km width of the Eastern Cordillera, the ~100–150 km of crustal shortening inferred from balanced cross sections and implied by recent estimates of crustal thickness would require ~25–40 Myr of shortening at ~4 mm/yr. The present‐day GPS measurements, therefore, are inconsistent with the inference, based on paleobotanical observations that the entire Eastern Cordillera rose 1500–2500 m since 3–6 Ma and called for a different interpretation of those data.