Investigation of Three-Dimensional Mantle Structure Beneath the SW Colorado Plateau and Southern Basin and Range

科罗拉多高原西南及南部盆地和山脉下方三维地幔结构调查

• 批准号: 9805149
• 负责人: George Zandt
• 金额: $ 7.99万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-15 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9805149&HistoricalAwards=false
• 关键词: Investigation; Three; Dimensional; Mantle; Structure

9805149ZandtThis research involves the study of the crust and upper mantle of the region encompassing southeastern California and western Arizona, which covers the southwest quarter of the Colorado Plateau and much of the southern Basin and Range. An existing data set from a 75-station, 200km by 450km array will be analyzed to complete a seismic tomography study, incorporating modeling of available digital Bouguer gravity data, and to model existing broadband waveforms to characterize the upper mantle structure in the study region. This important data set fills a large gap in high-resolution P-wave tomography coverage for the western U.S. The region's Cenozoic tectonic history of transition from subduction related compression and crustal thickening to orogenic collapse with core complex formation, volcanism, and extension is unusually well documented in the geologic record. This study will constrain the present day composition and physical state of the upper mantle beneath the area to evaluate the ways it has retained, or lost, the imprint of the Cenozoic tectonic events.

[805149] zandt这项研究包括对加利福尼亚东南部和亚利桑那州西部地区的地壳和上地幔的研究，该地区涵盖了科罗拉多高原的西南地区和南部盆地和山脉的大部分地区。将分析来自75个站点、200公里乘450公里阵列的现有数据集，以完成地震层析成像研究，结合现有数字布格重力数据的建模，并对现有宽带波形进行建模，以表征研究区域的上地幔结构。这一重要的数据集填补了美国西部高分辨率p波断层扫描覆盖范围的巨大空白。该地区的新生代构造历史从俯冲相关的压缩和地壳增厚过渡到造山崩塌，包括岩心复合体的形成、火山活动和伸展，在地质记录中得到了罕见的详细记录。这项研究将限制该地区下地幔目前的组成和物理状态，以评估它保留或丢失新生代构造事件印记的方式。