Collaborative Research: Constraining P-T-t-D Paths of Metamorphic Tectonites with the TitaniQ Thermobarometer

合作研究：使用 TitaniQ 温压计约束变质构造岩的 P-T-t-D 路径

• 批准号: 0948529
• 负责人: Laura Webb
• 金额: $ 19.45万
• 依托单位: University of Vermont & State Agricultural College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2014-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948529&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraining; Paths; Metamorphic

Collaborative Research: Constraining P-T-t-D paths of metamorphic tectoniteswith the TitaniQ thermobarometerIntellectual merit: The recent development of several trace-element thermometers has provided powerful new tools for geologists to constrain pressure-temperature-time-deformation (P-T-t-D) histories of many crustal rocks to understand their tectonic and petrologic histories. Key to this approach is the recent development of a Ti-in-quartz (TitaniQ) thermobarometer that can ideally provide T or P information from the content of Ti dissolved in quartz. This approach remains to be tested in a well-characterized environment. To this end, an integrated microstructural, petrologic, and geochemical study is proposed to evaluate P-T-t-D paths of metamorphic tectonites from well characterized and previously dated gneisses, schists, and mylonites from the Strafford Dome complex (Vermont). These rocks record progressive deformation during crenulation cleavage development and, locally, complete transposition of the S1 fabric and mylonitization. S1 is preserved as quartz-rich inclusions suites in minerals such as garnet, staurolite, and kyanite, suggesting that CL imaging combined with in situ analyses of Ti-in-quartz in different microstructural contexts from the same sample may elucidate discrete segments of the P-T-t-D path. Electron backscatter and CL imaging will be used to investigate the strain field associated with P-T conditions and provide insight into the physical processes associated with quartz reequilibration with respect to Ti distributions. What is unique about this study is the potential to determine not just the temperature, but also the depth at which a fabric is developed.Broader impacts: The proposed research efforts will foster collaboration at the interface of tectonics, petrology, and geochemistry. The project will support the research programs of two early career geoscientists (Webb and Thomas) and enhance graduate and undergraduate student education and training through the use of cutting-edge technology and hands-on field and laboratory experiences. Students will gain experience in linking observations from micron to plate scales. The results of this work will be broadly applicable to many problems in continental tectonics and disseminated at international meetings and in peer reviewed journals. Samples, field data and analytical data collected during the course of this study will be used in L. Webb's class, Microstructural Analysis and P-T-t-D Paths, for senior level undergraduate and graduate students at UVM. Photomicrograghs, CL images, and analytical data sets will be available to the scientific community for research and teaching through an NSF supported Database System for Metamorphic Geochemistry 'MetPetDB'.

Collaborative Research: Constraining P-T-t-D paths of metamorphic tectoniteswith the TitaniQ thermobarometerIntellectual merit: The recent development of several trace-element thermometers has provided powerful new tools for geologists to constrain pressure-temperature-time-deformation (P-T-t-D) histories of many crustal rocks to understand their tectonic and petrologic histories.这种方法的关键是最近开发了ti-in-Quartz（Titaniq）热验光计，该热计理想地可以从溶解在石英中的Ti含量中提供T或P信息。 这种方法仍有待测试的环境待测试。 为此，提出了一项综合的微结构，岩石学和地球化学研究，以评估来自Strafford Dome Complex（Vermont）的良好特征和以前的片麻岩，片岩和甲状腺菌的变质构造岩的P-T-T-D路径。这些岩石记录了裂解裂解发育过程中的渐进变形，并在局部对S1织物和麦芽髓化的完全换位。 S1被保留为石榴石，星状岩和kyanite等矿物质富含石英的夹杂物套件，这表明在来自同一样品的不同微结构环境中Ti-In-Quartz的原位分析结合了CL成像可能会阐明P-t-t-t-d路径的离散段。电子反向散射和CL成像将用于研究与P-T条件相关的应变场，并深入了解与Ti分布相对于石英重新启动相关的物理过程。这项研究的独特之处在于，不仅可以确定温度，还可以确定织物的深度。Broader的影响：拟议的研究工作将在构造，岩石学和地球化学的界面上促进协作。该项目将支持两位早期职业地球科学家（Webb和Thomas）的研究计划，并通过使用尖端技术以及动手实地领域和实验室经验来增强学生和本科生的教育和培训。学生将获得从微米到板尺度的观察结果的经验。这项工作的结果将广泛适用于大陆构造的许多问题，并在国际会议和同行评审期刊上进行了传播。在本研究过程中收集的样本，现场数据和分析数据将用于UVM的高级本科生和研究生，用于L. Webb的类，微结构分析和P-T-T-D路径。 Scientific Communition将通过NSF支持的变质地球化学“ MetPETDB”提供显微镜，CL图像和分析数据集，用于研究和教学。