Collaborative Research: Characterizing the Regional Fluid Flow System of the Wyoming Salient, Sevier Fold-Thrust Belt: Implications for Orogenic Wedge Deformation and Propagation

合作研究：描述怀俄明州突出的塞维尔褶皱逆冲带的区域流体流动系统：对造山楔形变形和传播的影响

• 批准号: 1450840
• 负责人: W.A. Yonkee
• 金额: $ 8.08万
• 依托单位: Weber State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2021-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1450840&HistoricalAwards=false
• 关键词: Collaborative; Research; Characterizing; Regional; Fluid

The goal of this project is to investigate the role that crustal fluids have played in deformational processes that created the classic Wyoming salient of the Cordilleran fold and thrust belt of the western United States. The Cordilleran orogenic belt is a major tectonic feature consisting of folds and faults that resulted from convergent margin tectonic activity due to subduction of the Farallon plate beneath the North American plate about 140 to 50 million years ago during the Sevier Orogeny. The Wyoming salient is considered to be an ideal place for this study given that it has been extensively studied and is of the best characterized fold and thrust belts in the world. The results of the project will provide insights into how fluids contribute to large-scale deformation associated with mountain building events, fault zone processes, and the results will have implications for a variety of disciplines that have societal relevance, including mineral exploration, hydrocarbon exploration, hydrology. In addition to the research goals of the project, the project will contribute to training of graduate and undergraduate students in a STEM discipline; collaboration between three universities; contributions to research infrastructure at at Ph.D. granting and primary undergraduate institutions; incorporation of research results into classroom curricula; and dissemination of research results via peer-reviewed publications, presentations at professional geoscience meetings, and by web accessible digital data sets. This project will innovatively integrate detailed structural, fluid inclusion, stable isotope, and geochronologic studies along transects across the curved Wyoming salient into the foreland and along traverses of key large-scale folds and major fault zones, providing extensive new regional data sets that relate fluid flow with progressive deformation. Although previous laboratory studies have provided insights into deformation micromechanisms and previous field and modeling studies of thrust belts have revealed the importance of fault zones and evolving topography on fluid flow systems, quantitative interrelations between regional to local fluid flow and progressive deformation within propagating fold-thrust wedges remains poorly understood. This project will build on previous structural studies in the Wyoming salient, with results synthesized to improve our understanding of feedbacks between fluid flow and thrust wedge mechanics. The project will test models of fluid-flow systems within curved fold-thrust belts, including nature of micro-, meso-, and megascopic fluid pathways; changing contributions of meteoric-, formation-, and metamorphic-waters during progressive wedge propagation and development of topography; evolving stratigraphic and structural compartmentalization of fluid flow as deformation changes style from distributed layer-parallel shortening to concentrated thrust slip; and propagation of detachment faults and early layer-parallel shortening in front of the fold-thrust wedge related to enhanced fluid flow and burial. This project will build on previous structural studies in the Wyoming salient, with results synthesized to improve our understanding of feedbacks between fluid flow and wedge mechanics. The project will combine a variety of methodologies, including mesoscopic structural analysis and sampling of veins/fracture sets, cleavage, and minor faults that provided fluid pathways,

该项目的目标是研究地壳流体在变形过程中所发挥的作用，该过程创造了美国西部科迪勒拉褶皱和冲断带的经典怀俄明州突出部。科迪勒拉造山带是一个主要的构造特征，由褶皱和断层组成，是约 140 至 5000 万年前塞维尔造山运动期间法拉隆板块俯冲到北美板块下方造成的会聚边缘构造活动造成的。怀俄明州突出部被认为是这项研究的理想地点，因为它已被广泛研究，并且是世界上特征最鲜明的褶皱和冲断带。该项目的结果将深入了解流体如何导致与造山事件、断层带过程相关的大规模变形，并且结果将对具有社会相关性的各种学科产生影响，包括矿产勘探、碳氢化合物勘探、水文学。除了该项目的研究目标外，该项目还将有助于培养 STEM 学科的研究生和本科生；三所大学之间的合作；对博士研究基础设施的贡献授予和初级本科院校；将研究成果纳入课堂课程；通过同行评审的出版物、专业地球科学会议上的演讲以及可通过网络访问的数字数据集传播研究成果。该项目将创新性地整合详细的结构、流体包裹体、稳定同位素和地质年代学研究，沿着穿过弯曲的怀俄明州凸起到前陆的横断面以及沿着关键的大规模褶皱和主要断层带的横断面，提供与流体相关的广泛的新区域数据集具有渐进变形的流动。尽管先前的实验室研究已经深入了解了变形微观机制，并且先前的冲断带现场和建模研究已经揭示了断层带和演化地形对流体流动系统的重要性，但区域到局部流体流动与传播褶皱逆冲内渐进变形之间的定量相互关系楔子仍然知之甚少。该项目将建立在怀俄明州突出部之前的结构研究的基础上，综合结果以提高我们对流体流动和推力楔块力学之间的反馈的理解。该项目将测试弯曲褶皱冲断带内的流体流动系统模型，包括微观、细观和宏观流体路径的性质；在楔形渐进传播和地形发展过程中，大气水、地层水和变质水的贡献不断变化；随着变形方式从分布层平行缩短到集中逆冲滑移，流体流动的地层和构造分区不断演变；滑脱断层的传播和褶皱逆冲楔前面的早期层平行缩短与流体流动和埋藏增强有关。该项目将建立在怀俄明州突出部之前的结构研究的基础上，综合结果以提高我们对流体流动和楔块力学之间的反馈的理解。该项目将结合多种方法，包括细观结构分析和对提供流体通道的静脉/裂缝组、解理和小断层进行采样，