Collaborative Research: Linking Fluid-rock Interaction and Strain Accumulation in a Naturally Deformed Diamictite, Implications for Hydrolytic Weakening and Reaction Softening

合作研究：将流体-岩石相互作用与自然变形杂岩中的应变积累联系起来，对水解弱化和反应软化的影响

• 批准号: 0838021
• 负责人: W.A. Yonkee
• 金额: --
• 依托单位: Weber State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0838021&HistoricalAwards=false
• 关键词: Collaborative; Research; Linking; Fluid; rock; Collaborative; Research; Linking; Fluid; rock

Understanding the strength and mechanical behavior of the continental lithosphere is a first-order issue in tectonics. Mechanical behavior of the lithosphere depends mostly on the development of weak and strong layers. In the laboratory, insight into this process can be gained through the study of reactions and deformation mechanisms in minerals, fluid flow, and fabric evolution. The wide range of temporal and spatial scales at work in deforming lithosphere presents challenges in extrapolating results from laboratory studies to natural mountain belts. Through a study of deformed diamictites, rocks composed of mainly mud and cobbles, these researchers will evaluate processes that reduced the rock strength and resulted in concentrated deformation. The deformation will be addressed through measurements of the shape changes that the cobbles have undergone. These studies will improve our understanding of how strong and weak parts of the crust evolve during mountain building, and processes that localize deformation into fault zones and partly control nucleation of large earthquakes. The investigators will integrate field, microtextural, and microchemical analyses of variably deformed and altered granitic gneiss and quartzite to quantify relationships between progressive strain, deformation mechanisms, and fluid-chemical processes. The diamictite displays a km-scale gradient in bulk deformation intensity, providing a record of hydrolytic weakening and reaction softening processes. Strain will be estimated for different clast types and sizes using the Rf/?Ö technique. Volume change will be estimated from geochemical changes and microstructural relations. Deformation mechanisms will be evaluated from petrographic studies of microstructures, combined with electron backscatter diffraction analysis of lattice preferred orientation and subgrain boundaries. Amounts and locations of water and related species, which control hydrolytic weakening, will be evaluated using Fourier transform infrared spectroscopy and synchrotron infrared radiation. Cathodoluminescence will provide data on locations of quartz neocrystallization and healed microcracks. Changes in bulk chemical composition of clasts and matrix will be quantified using X-ray fluorescence, X-ray spectral mapping and scanning electron microscopy. This combination of techniques will provide new information on the interactions between deformation, fluids, and chemical processes during progressive strain.

了解连续岩石圈的强度和机械行为是构造中的一阶问题。岩石圈的机械行为主要取决于弱层和强层的发展。在实验室中，可以通过研究矿物质，流体流量和织物进化的反应和变形机制来获得有关此过程的见解。在变形岩石圈方面工作时，各种临时和空间尺度在推断实验室研究到自然山带的结果方面提出了挑战。通过对主要由泥土和鹅卵石组成的岩石的变形陶瓷研究，这些研究人员将评估降低岩石强度并导致浓​​缩变形的过程。变形将通过测量鹅卵石经历的形状变化来解决。这些研究将提高我们对山地建筑过程中地壳演变的强度和弱部位的理解，以及将变形定位到断层区域并部分控制大地震的过程。研究人员将整合田间，微作用和微化学分析，对花岗岩片岩和石英岩的变化和改变，以量化渐进株，变形机制和流体化学过程之间的关系。二氧化脱虫显示出大量变形强度的KM规模梯度，提供了水解弱和反应软化过程的记录。使用RF/？Ö技术，将对不同的碎屑类型和尺寸估算应变。体积变化将从地球化学变化和微观结构关系中估计。将从微结构的岩石学研究中评估变形机制，并结合电子对晶格优选方向和亚晶界边界的反向散射分析。控制水解弱化的水和相关物种的量和位置将使用傅立叶转化感染的光谱和同步加速器感染的辐射进行评估。阴极发光将提供有关石英NeocryStallation和加热微裂纹位置的数据。将使用X射线荧光，X射线光谱映射和扫描电子显微镜来定量经典和基质的体积化学组成的变化。这种技术的组合将提供有关渐进株期间变形，流体和化学过程之间相互作用的新信息。