Collaborative Research: Late Cretaceous-Tertiary Foreland Basin Evolution in the Eastern Cordillera of Southern Bolivia

小行星9804680 人们普遍认为，沿南美洲西海岸沿着的弧-陆相互作用涉及到地壳的大幅度缩短，这种缩短既增厚了地壳，又使陆地表面的高度高于增厚的地壳，并在前陆位置形成盆地。 然而，玻利维亚至少有两个地壳增厚时期，只有较年轻的一个时期有文献记载。 较老的（晚白垩世至第三纪中期）逆冲推覆和前陆盆地演化的情节几乎没有记录，但需要评估总缩短和了解目前的地形和同造山沉积的起源。 该项目将研究这些沉积物，以检验其来源的两种假设。 这些结果有望在这些假设之间进行检验，并将安第斯山脉与其他弧后褶皱冲断带（如北美科迪勒拉山脉）进行严格的比较。

9804680 DeCelles It is generally acknowledged that the arc-continental interactions along the western coast of South America has involved major crustal shortening that has both thickened the crust and raised the elevation of the land surface over the thickened crust and formed basins in the foreland position. However, there are at least two periods of crustal thickening in Bolivia, and only the younger one has received documentation. The older (late Cretaceous to mid tertiary) episode of thrusting and foreland basin evolution remains virtually undocumented, yet is required to assess total shortening and to understand the origin of the present topography and syn orogenic deposits. This project will study these sediments in order to test two hypotheses for their origin. The results are expected to test between these hypotheses and also allow for a rigorous comparison between the Andes and other retroarc fold-thrust belts, such as the North American Cordillera.