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: 1450907
• 负责人: Gautam Mitra
• 金额: $ 21.52万
• 依托单位: University of Rochester
• 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 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1450907&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,

该项目的目标是调查地壳流体在形成美国西部科迪勒拉褶皱和冲断带典型怀俄明州凸起的变形过程中所起的作用。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，这些褶皱和断层是由于大约1.4亿至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之下而引起的会聚边缘构造活动造成的。怀俄明州凸起被认为是一个理想的地方，这项研究已被广泛研究，是最好的特征褶皱和冲断带在世界上。该项目的结果将深入了解流体如何促成与造山活动、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。研究成果的传播包括：在高等院校和初级本科院校开展研究;将研究成果纳入课堂课程;通过同行评审的出版物、在专业地球科学会议上的介绍以及通过网络可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构造、流体包裹体、稳定同位素和地质年代学研究，这些研究将沿着沿着横穿弯曲的怀俄明州凸起进入前陆的横断面，以及沿着横穿关键的大规模褶皱和主要断裂带，提供广泛的新的区域数据集，这些数据集将流体流动与渐进变形联系起来。虽然以前的实验室研究提供了深入了解变形的微观机制和以前的领域和模拟研究的冲断带揭示了断层带和不断变化的地形对流体流动系统的重要性，定量之间的相互关系区域局部流体流动和渐进变形内传播褶皱冲断楔仍然知之甚少。这个项目将建立在以前的结构研究在怀俄明州突出，结果合成，以提高我们的理解之间的反馈流体流动和推力楔力学。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、中观和宏观流体通道的性质;在地形的渐进楔形扩展和发展过程中，大气水、地层水和变质水的作用不断变化;随着变形方式从分布的平行层缩短转变为集中的逆冲滑动，流体流动的地层和构造分区不断变化;滑脱断层的扩展和褶皱-冲断楔前缘的早期层间缩短作用与流体流动和埋藏的增强有关。这个项目将建立在以前的结构研究在怀俄明州突出，结果综合，以提高我们的理解之间的反馈流体流动和楔形力学。该项目将结合联合收割机的各种方法，包括中观结构分析和静脉/裂缝集，裂解和提供流体通道的小断层取样，