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

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• 作者：Héctor Mora‐Páez ; David J. Mencin ; Peter Molnar ; Hans Diederix ; Leonardo Cardona‐Piedrahita ; Juan‐Ramón Peláez‐Gaviria ; Yuli Corchuelo‐Cuervo
• 刊名：Geophysical Research Letters
• 出版年：2016
• 出版时间：28 August 2016
• 年：2016
• 卷：43
• 期：16
• 页码：8407-8416
• 全文大小：1.7MB
• ISSN：1944-8007

文摘

GPS 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.