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.

虽然板块相互作用期间施加在岩石上的应力可能是普遍存在的，但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对比，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规模而异。 PI 提议揭示导致西班牙西南部伊比利亚南部剪切带这一主要构造结构的变沉积岩内各种尺度应变局部化的因素。由地球科学教师、研究生和本科生组成的多元化国际团队将通过国际实地研究和指导计划收集综合构造地质学、测绘学和地球化学数据集来开展这项研究。每年，四名本科生和一名研究生将在西班牙进行长达 4 周的实地考察，并在 UWM 进行至少 13 周的后续分析。岩石圈中的应变本地化过程是我们理解板块构造的基础。虽然变形可能普遍存在于整个构造带中，但变形强度通常是强烈局部化的。可能控制应变局部化的因素包括流变学对比和机械边界、矿物学或晶粒尺寸的差异、织物形成以及各种晶粒级软化机制，这些机制通常通过流体增强。 主要科学目标是阐明受南伊比利亚剪切带影响的变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实地研究和指导计划收集综合岩性、构造结构、微观结构、测绘学和地球化学数据集。该项目的优势在于来自一系列相对温和的研究生和本科生项目的集成数据集。 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景。 这些结果将有助于进一步了解各种构造环境中其他变质岩单元中的应变局部化和剪切带形成。 该计划还将提高学生获得国际研究经验的职业生涯。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。