Collaborative Research: Geodetic Constraints on the Tectonic Processes Operating at the East Flank of the Central Andean Plateau

合作研究：安第斯高原中部东侧构造过程的大地测量约束

• 批准号: 0948615
• 负责人: James Foster
• 金额: $ 33.65万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-15 至 2014-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948615&HistoricalAwards=false
• 关键词: Collaborative; Research; Geodetic; Constraints; Tectonic

A team of scientists from Ohio State University and the University of Hawaii is constructing a dense GPS network over the entire eastern flank of the Andean Plateau within Bolivia and northernmost Argentina in order to address a variety of questions about orogenic wedge processes and Andean plateaus margin kinematics. The project will to study contemporary patterns of deformation in the Andean Plateau, and focus on its eastern flank, which is comprise of the Eastern Cordillera, the Interandean Zone, and the Subandes. To better understand orogenic wedge processes they research team will: (1) determine whether a strong eastern flank velocity gradient is a signal of a slipping-locked transition zone on the basal decollement or of out-of-sequence thrusting; (2) measure differences in the width of the active wedge north and south of the Santa Cruz bend and determine its relationship to the differences in rainfall (as a proxy for erosion) on either side of the bend; (3) assess mechanisms by which active shortening is transferred from the deeper, inboard portions of a plateau to the shallower outboard wedges. Andean plateau kinematics will be elucidated by: (1) determination of the kinematic framework of the east flank of the Andean plateau; (2) measurement of the variation of active shortening along-strike; (3) assessment of the influence of paleogeography and foreland basin stratigraphy on crustal displacement and foreland shortening; (4) examination of the relationship between the absence of Paleozoic sediments in the foreland basin of the Chapare region and the Cochabamba Shear Zone; (5) exploration for evidence of extrusion tectonics in the main physiographic transition or topographic ramp above the northern Subandes.Orogenic plateaus have formed throughout much of geological history, and because they are produced by massive crustal thickening accompanied by large scale crustal melting, their formation plays an important role in the evolution of continental crust. The best prospect for understanding the mechanisms responsible for plateau orogenesis is the study of active continental plateaus, such as the plateau in the central Andes. Current theories for the development of this high plateau suggest either a slow two-stage uplift process or a rapid uplift scenario. This study will provide data that will contribute to the resolution of this controversy as well as improve understanding of the active processes along the plateau's eastern margin. This project should lead to a deeper understanding of the way that mountain belts and topographic plateaus deform. The research should improve understanding of the generation of earthquakes in the highly populated regions flanking high mountains.

俄亥俄州立大学和夏威夷大学的一支科学家团队正在玻利维亚和阿根廷北部的安第斯高原的整个东部侧面建立一个密集的GPS网络，以解决有关灌木楔形工艺的各种问题，以及安第斯Plateaus Margin Kinematics。该项目将研究安第斯高原（Andean Plateau）的当代变形模式，并专注于其东部侧面，该侧面由东部科迪勒拉（Cordillera），国际山脉（Interandean）区和郊区组成。为了更好地理解他们研究团队的造山间楔形过程：（1）确定强大的东部侧面速度梯度是基础脱落上滑动锁定的过渡带还是超出序列推力的信号； （2）测量圣克鲁兹弯曲北部和南部的活动楔形宽度的差异，并确定其与弯曲两侧降雨差异（作为侵蚀的代理）的关系； （3）评估主动缩短的机制，从高原的较深的内侧部分转移到较浅的舷外楔子。安第斯高原运动学将通过以下方式阐明：（1）确定安第斯高原东侧的运动学框架； （2）测量沿撞击的主动缩短变化； （3）评估古地理和前陆盆地地层对地壳位移和前陆缩短的影响； （4）检查Chapare地区前陆盆地的古生代沉积物与Cochabamba剪切带之间的关系； （5）探索在北部外代上方的主要生理过渡或地形坡道中挤压构造的证据。孔子高原在整个地质历史的大部分地区都形成，并且由于它们是由大规模的地壳融化而伴随着大规模的地壳融化而产生的，因此它们的形成起着重要的作用。理解负责高原造山造成机制的最佳前景是研究活跃的大陆高原，例如安第斯山脉中部的高原。目前的发展高原的理论表明，要么是缓慢的两阶段升高过程，要么快速提升场景。这项研究将提供有助于解决这一争议的数据，并提高对高原东边缘的主动过程的理解。该项目应该更深入地了解山带和地形高原变形的方式。这项研究应提高人们对高山脉侧面高度人口稠密地区地震产生的理解。