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

该项目的目标是调查地壳流体在变形过程中所起的作用，这些变形过程创造了美国西部科迪勒褶皱和逆冲带经典的怀俄明州凸起。科迪勒造山带是一个由褶皱和断层组成的主要构造特征，这些褶皱和断层是大约1.4亿~5000万年前Sevier造山运动期间法拉隆板块俯冲到北美板块下方而导致的边缘会聚构造活动的结果。怀俄明州凸起被认为是进行这项研究的理想地点，因为它已经得到了广泛的研究，并且是世界上最具特征的褶皱和逆冲带。该项目的结果将提供有关流体如何促成与造山事件、断裂带过程相关的大规模变形的见解，并将对具有社会意义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，该项目还将有助于对STEM学科的研究生和本科生进行培训；三所大学之间的合作；为科学、技术和经济研究中心的研究基础设施作出贡献；在授予博士学位和初级本科院校之间开展合作；将研究成果纳入课堂课程；通过同行评议的出版物、在专业地球科学会议上所作的介绍以及可从网上获取的数字数据集来传播研究成果。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进入前陆的横断面以及关键的大型褶皱和主要断裂带的横断面，提供大量新的区域数据集，将流体流动与渐进变形联系起来。尽管以前的实验室研究已经提供了对变形微观机制的见解，以前的逆冲带的现场和模拟研究揭示了断裂带和不断演变的地形对流体流动系统的重要性，但区域到局部流体流动与不断传播的褶皱-逆冲楔形体内的渐进变形之间的定量相互关系仍然知之甚少。这个项目将建立在怀俄明州凸起以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形力学之间的反馈的理解。该项目将测试弯曲褶皱冲断带内流体流动系统的模型，包括微观、中观和巨观流体通道的性质；在楔形递进传播和地形发育过程中，大气、地层和变质水的贡献变化；随着变形方式从分布层平行缩短转变为集中逆冲滑动，流体流动的地层和构造分区的演变；以及与增强流体流动和埋藏有关的褶皱冲断楔前拆离断层和早期层平行缩短的传播。这个项目将建立在怀俄明州凸起以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形力学之间的反馈的理解。该项目将结合各种方法，包括对静脉/裂缝组、解理和提供流体通道的小断层进行介观结构分析和采样，

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,