GPS velocities and the construction of the Eastern Cordillera of the Colombian Andes
GPS velocities and the construction of the Eastern Cordillera of the Colombian Andes
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GPS 速度与哥伦比亚安第斯山脉东部科迪勒拉山脉的构造
DOI：
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发表时间：
2016
期刊：
影响因子：
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通讯作者：
Yuli Corchuelo
中科院分区：
文献类型：
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作者：
H. Mora;D. Mencin;P. Molnar;H. Diederix;Leonardo Cardona;Juan‐Ramón Peláez‐Gaviria;Yuli Corchuelo
横跨哥伦比亚东部科迪勒拉东北方向的全球定位系统速度显示出斜交收敛的速度为8.8 ± 1.7 mm/yr，其中包括沿山脉的右旋走滑剪切8.0 ± 1.7 mm/yr和西北东南缩短的3.7 ± 0.3 mm/yr。更快的辐合只发生在科迪勒拉的东北端，那里的东部边缘向西北方向发展，那里是最高的山脉所在的地方。走滑剪切证实了地质工作，表明这种运动在山脉的西南和东北方向。考虑到科迪勒拉东部约200公里的宽度，从平衡横截面推断和最近的地壳厚度估计所暗示的约100-150 公里的地壳缩短将需要以约4 毫米/年的速度缩短约25-40Myr。因此，今天的全球定位系统测量结果与根据古植物学观察得出的推断不一致，即自3-6 Ma以来，整个东科迪勒拉上升了1,500-2,500 m，并要求对这些数据进行不同的解释。
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.