Paleotectonic Controls on the Boundary Between Thin and Thick-Skinned Deformation

褶皱/冲断带表现出两种截然不同的构造样式——基底型（厚皮）和盖层型（薄皮）。先前的研究表明，厚皮和薄皮变形在30年代的安第斯山脉同时活跃，边界发生在中部前科迪勒拉和东部前科迪勒拉之间的一个几何三角形地带。该项目将使用独特的工业地震反射数据集和实地工作来调查假设，即结构几何形状的巨大变化是由阿根廷西部地壳中预先存在的各向异性控制的。研究结果有助于解释褶皱冲断带厚或薄变形类型的控制因素。

9418087 Allmendinger Two fundamentally different tectonic styles are exhibited by fold/thrust belts- those involving basement (thick-skinned) and those involving only cover (thin skinned). Previous work has shown that thick and thin-skinned deformation are both active simultaneously in the Andes at 30oS, and the boundary occurs across a geometric triangle zone between the central precordillera and the eastern precordillera, Sierra Pampeanas. This project will use a unique industry seismic reflection data set and fieldwork to investigate the hypothesis that the dramatic change of structural geometry is controlled by preexisting anisotropies in the crust of western Argentina. Results should help explain the controls on thick or thin deformation styles in fold-thrust belts.