Lithospheric Structure and Deformation of the Flat Slab Region of Argentina

University Of Arizona, Tucson AZ

Investigators

Abstract

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 the world 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.