Integrated Structural and Hydrologic Charactrization of Fault Zone Permeability at Well Field to Regional Scales

区域尺度井场断裂带渗透性的综合结构和水文表征

• 批准号: 0610027
• 负责人: Shemin Ge
• 金额: --
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0610027&HistoricalAwards=false
• 关键词: Integrated; Structural; Hydrologic; Charactrization; Fault

0610027GECurrent understanding of fault-zone permeability at regional scales is limited. Particularly,permeability measurements across faults are scarce. Yet, there are clear indications that faultshave large hydrogeologic impacts on various geologic processes at this scale, as evidenced byvariable hydraulic head gradients, geochemical and geothermal anomalies across faults. Thereremain questions that are scientifically fundamental and practically significant regarding largescalepermeability of fault zones and their impact on aquifers. For example, how geologic andhydrologic information can be best integrated to effectively constrain regional-scale faultpermeability? While existing knowledge on fault permeability at small scales is indispensablescientifically, ultimately, it is the regional-scale permeability that is needed in conceptual andnumerical models for solving problems related to water resource management and transport offluid, solute, and energy in the Earth's crust.The scientific objective of this research is to characterize fault-zone permeability at the wellfieldto regional scale with constraints from field-based structural observations, hydrogeologictesting, and interpretation from conceptual and numerical modeling. The basis hypotheses arethat distinctive hydrogeologic responses around a fault could be observed from cross-faultaquifer tests and that fault-zone permeability features could be established from a comprehensiveunderstanding of the outcrop structural characteristics, borehole data of host rocks, andhydrogeologic tests conducted at multiple scales. Using the Elkhorn thrust fault in Colorado as afield site, the research plan consists of the following: (1) to characterize the geology and internalstructure of the fault zone to better understand the influence of juxtaposition of differentlithologies on fault-zone hydrogeologic properties, (2) to drill and core new boreholes throughthe fault zone to obtain direct field observations for fault-zone permeability, (3) to conduct crossfaultpumping tests in the new and preexisting holes to provide the much need directmeasurements on fault-zone permeability, and (4) to develop a fault-zone permeability model,through numerical modeling that integrates geologic, hydrogeologic, and geophysical field data.Three aspects of the intellectual merit are recognized. First, the study takes a new directionin characterizing fault-zone permeability by closely linking geologic observations andhydrogeologic testing data. Second, this proposed research offers the opportunity to gainhydrogeologic insight into a particular type of fault that is common but highly understudied - a thrust fault with a crystalline hanging wall and sedimentary footwall at regional basin scales. Finally, the cross-fault permeability tests coupled with geologic characterization planned in this research will be a significant advance in characterizing fault-related permeability by providing much-needed field measurement data.The major aspect of the broader impact of this proposed research is on enhancingundergraduate students experience in hydrogeology, in addition to training graduate students and contributing to better groundwater resource management in the western US. This research will benefit a large group of undergraduate students. Undergraduate students will be involved in all stages of this project. Specific approaches to implement this commitment include: (1) Recruit top undergraduates to conduct honor theses, (2) Field exercise related to an upper-division hydrogeology class. Groundwater level mapping and aquifer tests can be incorporated into class related activities, and (3) Drilling new boreholes will be coordinated so that students can observethe operation. Finally, the PIs plan to co-teach a two-credit two-week summer undergraduate field hydrogeology class. The research will provide an excellent venue for many different projects for this field class and help to realization of this plan.

0610027在区域尺度上对断层渗透性的理解有限。特别是，跨断层的渗透性测量很少。然而，有明确的迹象表明，断层对在此规模的各种地质​​过程的大型水文地质影响有很大的影响，这证明了跨断层的缩写液压头部梯度，地球化学和地热异常。 Thereremain问题在科学基本上是关于断层区域及其对含水层的影响的基本和实际上意义的。例如，如何最好地整合地质和水力学信息以有效地限制区域尺度的故障质量？尽管在小尺度上存在关于故障渗透性的现有知识是无关紧要的，但最终是概念性和数字模型中所需的区域尺度渗透性，以解决与水资源管理和地球外溶质和能量有关的问题。这项研究的科学目的是表征Wellfieldto区域尺度上的断层区渗透性，并从基于现场的结构观察，水文地质造影以及概念和数值建模的解释中受到限制。可以从交叉塔基法测试中观察到围绕故障的独特水文回应的基础假设，并且可以通过对露头结构特征的全面理解，宿主岩石的钻孔数据的全面理解，宿主岩石，和氢地质测试在多个级别级别进行。使用科罗拉多州的Elkhorn推力断层作为远处站点，研究计划包括以下内容：（1）表征断层区的地质和内部结构，以更好地了解不同算法对断层区域水理学特性的并置的影响）通过断层区钻和核心新的钻孔，以获得断层区渗透性的直接现场观测值，（3）在新的和先前存在的孔中进行CrossFaultPumpumping测试，以提供对断层区域通透性的急需直接测量，以及（4）通过整合地质，水文地质和地球物理场数据的数值建模来开发断层区的渗透率模型。认识到智力优点的三个方面。首先，该研究通过紧密联系地质观测和水理地质测试数据来迈出一个新的方向，该方向表征了断层区的通透性。其次，这项拟议的研究为获得特定类型的断层洞察力提供了机会，该类型的断层是常见但经过高度研究的特定类型 - 在区域盆地尺度上的结晶悬挂壁和沉积脚壁的推力断层。最后，通过提供急需的现场测量数据来表征与故障相关的渗透性的跨道透透性测试以及计划在本研究中计划的地质表征，这将是一个重要的进步。除了培训研究生外，学生在水文地质学方面的经验以及为美国西部更好的地下水资源管理做出贡献。这项研究将使大量的本科生受益。本科生将参与该项目的所有阶段。实施此承诺的具体方法包括：（1）招募顶级大学生以进行荣誉论文，（2）与上级水文地质学类有关的现场练习。地下水位映射和含水层测试可以纳入相关的活动中，（3）钻孔新的钻孔将进行协调，以便学生可以观察操作。最后，PIS计划共同讲述为期两周的两周夏季本科地质地质学课程。这项研究将为许多不同的项目提供一个理想的场所，并有助于实现该计划。