Lithospheric Structure and Deformation of the Flat Slab Region of Argentina

我们对薄皮冲断带和碰撞造山带和非碰撞造山带中的高原系统的认识取得了重大进展。然而，我们的理解如何厚皮变形形成的构造背景下，平坦俯冲落后。同样，俯冲带过程的研究也取得了很大进展，但我们仍然缺乏一个清晰的认识是什么控制了平板俯冲和地幔过程的影响。世界上研究平面俯冲和大陆变形之间联系的最佳地点之一是阿根廷西部的前科迪勒拉和Sierras Pampeanas。在这个项目中，调查人员建议使用所有现有的地震数据，并收集额外的数据与40站宽带地震部署的Sierras Pampeanas和平板的高分辨率成像。他们将建立在他们以前在阿根廷的CHARGE项目中的工作成果的基础上，以回答一些关于平坦俯冲和前陆基底变形的问题。这一建议的更广泛影响包括改善阿根廷、智利和法国圣胡安国立大学地震学家之间的国际合作，以及对研究生和本科生的培训。阿根廷的Sierras Pampeanas具有非常高的地壳地震活动率，并且有破坏性7级地震的历史（1944年，1977年）。这项研究将有助于更好地了解地震灾害，并通过提供更好的速度模型直接改善该地区的地震定位和震源研究。该结果对于美国西部拉拉米德变形的研究具有重要意义，这是地球观测科学的既定目标之一。

Major advances have occurred in our understanding of thin-skinned thrust belts and plateau systems in both collisional and noncollisional mountain belts. However, our understanding of how thick-skinned deformation forms in a tectonic setting of flat subduction has lagged behind. Similarly much progress has been made in the study of subduction zone processes but we still lack a clear understanding of what controls flat slab subduction and the impact on mantle processes. One of the best places in theworld to study the link between flat subduction and continental deformation is in the Precordillera and Sierras Pampeanas of western Argentina. In this project, the investigators propose to use all existing seismic data and collect additional data with a 40-station broadband seismic deployment for high resolution imaging of the Sierras Pampeanas and the flat slab. They will build on results from their previous work in Argentina in the CHARGE project to answer a number of questions about flat subduction and the deformation of the foreland basement. Among the broader impacts of this proposal are improving the international collaboration among seismologists from the National University in San Juan, Argentina, Chile and France and the training of graduate and undergraduate students. The Sierras Pampeanas of Argentina have a very high rate of crustal seismicity and have a history of devastating magnitude 7 earthquakes (1944, 1977). This study will contribute to a better understanding of earthquakes hazards and directly improve earthquake locations and source studies in the region by providing better velocity models. The results will be important for the study of the Laramide deformation in the western U.S., one of the stated objectives for Earthscope science.