Cenozoic Migration of Topography in the North American Cordillera Recorded in Coupled Basin-Detachment Systems

盆地-拆离系统耦合记录的北美科迪勒拉山脉新生代地形迁移

• 批准号: 0609649
• 负责人: C. Page Chamberlain
• 金额: $ 28.78万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0609649&HistoricalAwards=false
• 关键词: Cenozoic; Migration; Topography; North; American

This research group is conducting a paleoaltimetry study of basin-metamorphic core complex pairs within the northern Basin and Range and contiguous Rocky Mountains in order to reconstruct the Cenozoic elevational history of this region and to test competing hypotheses of the driving forces for extension. Tectonic models based on these hypotheses can be broadly associated with three competing surface uplift and extension mechanisms: (1) impingement of the Yellowstone hot spot plume at the base of the lithosphere, (2) delamination of mantle lithosphere, and (3) buoyancy-related flow driven by gradients in gravitational potential energy. Each of these models predicts distinct and testable topographic responses. Cenozoic paleoelevation history is being reconstructed for metamorphic core complexes and adjacent basins in Montana, Nevada, and Utah using stable isotope methods. This paleoaltimetry study will provide a unique set of constraints, which combined with geophysical and geologic data sets, should yield a better understanding of the driving forces behind Cenozoic extension in the northern Basin and Range and the North American Cordillera. This research project builds upon previous paleoelevation studies of metamorphic core complexes and intermontane basins in the western United States that suggest a history of spatially and temporally varying topographic development of western North America with surface uplift migrating southward with time.Large mountain ranges are found on all the Earth's continents. How these mountain ranges grow, however, remains one of the more elusive questions in earth sciences. Understanding the topographic history of mountain ranges is critical for evaluating different tectonic models as well as determining how the growth of mountains affects climate change. This is particularly true for the Cenozoic (last 65 million years of Earth's history) because it has been proposed that the construction of the large Cenozoic mountain belts, such as the Himalaya/Tibet and western North America Cordillera, have altered the Earth's climate. This study examines the Cenozoic topographic and climate history of the western U.S. Cordillera using stable isotope paleoaltimetry and evaluates the tectonic models that have been proposed for this region. It will provide new insights regarding how the American western mountain ranges formed as well as critical information on the links and feed-backs between growth of mountain ranges and climate.

该研究小组正在对北部盆地内和山脉和连续的岩石山脉内的盆地超态核心复合物对进行古钙化研究，以便重建该地区的可去研究高度历史，并测试驱动力的竞争假设以进行扩展。基于这些假设的构造模型可以与三种竞争性的表面隆升和扩展机制广泛相关：（1）构成岩石圈底部的黄石热点羽流，（2）地幔岩石圈的分层，以及（3）浮力相关的流动驱动的梯度由重力势能中的梯度驱动。这些模型中的每一个都预测了明显且可测试的地形响应。使用稳定的同位素方法，正在针对蒙大拿州，内华达州和犹他州的变质核心复合物和邻近盆地重建新生代古征史。这项古占学研究将提供一套独特的约束，结合地球物理和地质数据集，应该更好地了解北盆地和范围内的新生代延伸后的驱动力，以及北美山脉。该研究项目基于美国西部的变质核心复合物和跨蒙托坦盆地的先前的古平均研究，这表明了西部北美西部的空间和时间变化的地形发展历史，随着时间的流逝，地表隆起向南迁移。极端的山脉建立在地球上。 然而，这些山区的增长方式仍然是地球科学中最难以捉摸的问题之一。 了解山脉的地形历史对于评估不同的构造模型以及确定山的生长如何影响气候变化至关重要。 对于新生代（地球历史的最后6500万年）来说，尤其如此，因为已经提出，在喜马拉雅山/西藏和北美西部的大型新生代山带的建设改变了地球的气候。这项研究研究了使用稳定的同位素古占地法的新生代地形和气候历史，并评估了该地区提出的构造模型。它将提供有关美国西部山区范围如何形成的新见解以及有关山脉和气候增长之间的联系和饲料的关键信息。