IRES Track I: Lithological controls on strain localization in metasedimentary rocks along the Southern Iberian Shear Zone

IRES Track I：南伊比利亚剪切带变沉积岩应变局部化的岩性控制

• 批准号: 1854155
• 负责人: Dyanna Czeck
• 金额: $ 30万
• 依托单位: University of Wisconsin-Milwaukee
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-15 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1854155&HistoricalAwards=false
• 关键词: IRES; Track; Lithological; controls; strain

While stresses imparted on rocks during plate interactions may be pervasive, the characteristic structures formed by them that facilitate rock deformation are generally localized. Deformation or strain localization is an important phenomenon throughout the crust, resulting in major contrasts in rock strength that impact crustal architecture and tectonics, fluid flow, and potential seismicity. The researchers hypothesize that the factors that control strain localization vary by scale. The PI proposes to unravel the factors causing strain localization at a variety of scales within metasedimentary rocks at a major tectonic structure, the Southern Iberian Shear Zone in southwestern Spain. A diverse, international team of geoscience faculty, graduate students, and undergraduate students will perform this research by collecting integrated structural geology, geomatics, and geochemical datasets through an international field-based program of research and mentorship. Each year, four undergraduates and one graduate student will spend up to four weeks in Spain conducting fieldwork and perform follow-up analyses at UWM for a minimum of 13 weeks.Strain localization processes in the lithosphere are fundamental to our understanding of plate tectonics. While deformation may be pervasive throughout tectonic zones, deformation intensity is often strongly localized. Factors that may control strain localization include rheology contrasts and mechanical boundaries, differences in mineralogy or grainsize, fabric formation, and various grain-scale softening mechanisms, which are often enhanced by fluids. The primary scientific goal is to unravel multi-faceted causes of strain localization within metasedimentary rocks affected by the Southern Iberian Shear Zone and determine if and how they vary with scale. Faculty, graduate students, and undergraduate students will collect integrated lithology, tectonic fabric, microstructure, geomatics, and geochemical datasets through a field-based program of research and mentorship. The strength of this project lies in the integrated datasets derived from a suite of relatively modest graduate and undergraduate student projects. Brought together through careful spatial mapping and the integrated 3D digital model, these disparate datasets can create a holistic picture of strain localization. These results will help further our understanding of strain localization and shear band formation in other metapelitic units in a wide array of tectonic settings. The program will also enhance the careers of students as they gain international research experience.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

虽然在板块相互作用过程中施加在岩石上的应力可能是普遍的，但由它们形成的促进岩石变形的特征结构通常是局部的。 变形或应变局部化是整个地壳的一个重要现象，导致岩石强度的重大差异，影响地壳结构和构造，流体流动和潜在的地震活动。 研究人员假设，控制应变定位的因素因尺度而异。 PI提出要解开在一个主要的构造结构，在西班牙西南部的南伊比利亚剪切带内的变质沉积岩在各种规模的应变局部化的因素。地球科学教师，研究生和本科生的多元化，国际团队将通过收集综合结构地质学，地理信息学和地球化学数据集通过国际实地研究和指导计划进行这项研究。每年，四名本科生和一名研究生将在西班牙进行为期四周的实地考察，并在UWM进行至少13周的后续分析。岩石圈中的应变局部化过程是我们理解板块构造的基础。虽然变形可能遍布整个构造带，但变形强度往往强烈局部化。可能控制应变局部化的因素包括流变学对比和机械边界、矿物学或粒度差异、组构形成和各种颗粒尺度软化机制，这些机制通常由流体增强。 主要的科学目标是解开受南伊比利亚剪切带影响的变质沉积岩内应变局部化的多方面原因，并确定它们是否以及如何随规模变化。教师，研究生和本科生将通过基于实地的研究和指导计划收集综合岩性，构造结构，微观结构，地理信息学和地球化学数据集。该项目的优势在于从一套相对温和的研究生和本科生项目中获得的综合数据集。 通过仔细的空间映射和集成的3D数字模型，这些不同的数据集可以创建应变定位的整体图像。 这些结果将有助于我们进一步了解应变局部化和剪切带的形成在其他变质单元在广泛的构造环境。 该计划还将提高学生的职业生涯，因为他们获得国际研究经验。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。