Development of a 4-D Model of Crustal Evolution in the Northern Rocky Mountains

落基山脉北部地壳演化 4 维模型的开发

• 批准号: 0545751
• 负责人: Paul Mueller
• 金额: $ 21.65万
• 依托单位: University of Florida
• 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: 2006-04-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0545751&HistoricalAwards=false
• 关键词: Development; Model; Crustal; Evolution; Northern

0545751MuellerIn order to optimize current and future deployment of EarthScope (ES) resources in the northern Rocky Mountains/Great Plains, a group of earth scientists from the University of Florida, Montana State University, and the U.S. Geological Survey are conducting research directed toward development of an integrated temporal and spatial (i.e., 4-D) framework for crustal evolution in this region. In particular, this region contains one of the most enigmatic segments of continental crust in North America, the Great Falls tectonic zone (GFTZ). This long-lived crustal structure has the most temporally extensive rock record in North America (ages to 4 billion years) and has had a major impact on the geologic history of this region, including younger episodes of faulting and seismicity, distribution of magmatism and ore deposits, and the creation of resource-rich sedimentary basins. For example, the intersection of the GFTZ and Trans-Hudson orogen, which developed ~ 1.8 billion years ago, is now the site of a major petroleum resource province, the Williston basin. Similarly, Phanerozoic structural reactivation, magmatism, seismicity, and mineralization in the northern Rocky Mountains is concentrated in the GFTZ, which leads to additional possibilities of how ancient structures and events may control modern earth processes and the distribution of resources.The research group is applying modern geochronologic (ion probe U-Pb), thermochronologic (multi-and single grain 40Ar-39Ar), and geochemical (major and trace elements) techniques to samples from outcrops, deep test wells, and xenoliths (pieces of the mantle and lower crust brought to the surface via volcanic eruptions). These results will be critical for both optimizing the deployment of ES resources and ultimately developing an integrated 4-D framework for the northern Rocky Mountain/northern Great Plains portion of North America. This 4-D framework is essential to: 1) unraveling one of the most intriguing episodes of continent formation in the geologic record, the formation of Laurentian North America; 2) understanding how the amalgamating collisional events were recorded in the crust and mantle; and 3) to what extent these ancient events affected subsequent crustal and lithospheric evolution in the northern Rocky Mountains/Great Plains. The research team is utilizing facilities from all three organizations (University of Florida, Montana State University, and the U.S. Geological Survey). Student participation at the graduate and undergraduate level is providing critical workforce training in geologic and analytical skills. The results of this research will be integrated into the evolving Montana GIS/DEM geologic map base being developed at Montana State University. All of the geochemical and geochronologic data will be numerically and spatially displayed in an interactive web format and accessible to geoscientists, educators, and the general public. Results will also be disseminated via meeting presentations and peer reviewed journals.

0545751Mueller为了优化当前和未来在落基山脉/大平原北部部署 EarthScope (ES) 资源，来自佛罗里达大学、蒙大拿州立大学和美国地质调查局的一组地球科学家正在开展研究，旨在开发该地区地壳演化的综合时空（即 4-D）框架。 特别是，该地区包含北美大陆地壳最神秘的部分之一——大瀑布构造带（GFTZ）。 这种长寿的地壳结构拥有北美最广泛的岩石记录（年龄可达 40 亿年），对该地区的地质历史产生了重大影响，包括较年轻的断层活动和地震活动、岩浆活动和矿石的分布矿床，并形成资源丰富的沉积盆地。 例如，约 18 亿年前开发的 GFTZ 和 Trans-Hudson 造山带的交汇处，现在是主要石油资源省威利斯顿盆地的所在地。 同样，落基山脉北部的显生宙构造再活化、岩浆活动、地震活动和矿化集中在 GFTZ，这为古代构造和事件如何控制现代地球过程和资源分布提供了更多可能性。该研究小组正在应用现代地质年代学（离子探针 U-Pb）、热年代学（多颗粒和单颗粒 40Ar-39Ar）和地球化学（主量元素和微量元素）技术对露头样品进行深度测试井和捕虏体（通过火山喷发带到地表的地幔和下地壳碎片）。 这些结果对于优化 ES 资源的部署以及最终为北美落基山脉北部/大平原北部部分开发综合 4-D 框架至关重要。 这个 4-D 框架对于以下方面至关重要：1）揭示地质记录中大陆形成过程中最有趣的事件之一，劳伦北美的形成； 2）了解如何在地壳和地幔中记录合并碰撞事件； 3）这些古代事件在多大程度上影响了落基山脉北部/大平原随后的地壳和岩石圈演化。 该研究小组正在利用所有三个组织（佛罗里达大学、蒙大拿州立大学和美国地质调查局）的设施。 研究生和本科生的学生参与提供了地质和分析技能方面的关键劳动力培训。 这项研究的结果将被整合到蒙大拿州立大学正在开发的不断发展的蒙大拿 GIS/DEM 地质图库中。 所有地球化学和地质年代学数据都将以交互式网络格式在数字和空间上显示，并可供地球科学家、教育工作者和公众访问。 结果还将通过会议演示和同行评审期刊传播。