Lithospheric Structure and Deformation of the Flat Slab Region of Argentina

阿根廷平板区岩石圈结构与变形

• 批准号: 0510966
• 负责人: Susan Beck
• 金额: $ 54.75万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0510966&HistoricalAwards=false
• 关键词: Lithospheric; Structure; Deformation; Flat; Slab

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.

我们对碰撞和非碰撞山带中薄皮冲断带和高原系统的认识取得了重大进展。然而，我们对厚皮变形是如何在平坦俯冲的构造背景下形成的理解落后了。同样，对俯冲带过程的研究也取得了很大进展，但我们对控制平板俯冲的因素及其对地幔过程的影响仍缺乏明确的认识。世界上研究平坦俯冲和大陆变形之间关系的最佳地点之一是阿根廷西部的Precordillera和sierra Pampeanas。在这个项目中，研究人员建议使用所有现有的地震数据，并通过40个站点的宽带地震部署收集额外的数据，以获得Pampeanas山脉和平板的高分辨率成像。他们将以之前在阿根廷CHARGE项目中取得的成果为基础，回答一些关于平坦俯冲和前陆基底变形的问题。这项提议的更广泛的影响包括改善来自圣胡安、阿根廷、智利和法国的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。阿根廷的帕米亚山脉地壳地震活动率很高，历史上曾发生过破坏性的7级地震（1944年、1977年）。这项研究将有助于更好地了解地震的危害，并通过提供更好的速度模型直接改善该地区的地震位置和震源研究。这一结果对于研究美国西部的拉拉米形变非常重要，这是地球观测科学的既定目标之一。