Kinetics of garnet nucleation and growth during metamorphism

变质作用过程中石榴石成核和生长的动力学

• 批准号: 386491-2010
• 负责人: Gaidies, Fred
• 金额: $ 1.82万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2014
• 资助国家: 加拿大
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=550454
• 关键词: Kinetics; garnet; nucleation; growth; during

The proposed research aims at a quantitative understanding of two fundamental processes during rock formation: nucleation and crystal growth. The rates and mechanisms of these processes will be investigated and their influences on the size and spatial distribution and chemical composition of the mineral content of rocks will be studied. The sizes and shapes of all the mineral grains in a rock and their mutual interrelationships define the texture of the rock. My research will provide new insights into the nature and rates of texture formation. This is important since rock-texture fundamentally contributes to bulk rock properties such as electrical conductivity, strength and the way solid Earth responds to changes in external forces. Only little is known about the mechanisms that control rock-texture formation and novel findings are required. A major focus of my research will be on the crystallization of garnet during rock metamorphism. Garnet is chosen because its chemical composition reflects the pressure (P) and temperature (T) conditions that prevailed in the Earth's crust during crystallization. It also allows for the determination of the rates with which P and T changed through time. This information is fundamental for an understanding of the tectonic evolution of mountain belts. Numerical models that simulate garnet crystallization will be developed and calibrated with mineral chemistries and textures observed in rocks. Progress will be made on the quantification of the rates of chemical equilibration during metamorphism. This is needed to correctly interpret mineral zoning and mineral assemblages on which so much tectonic interpretation depends. Funds are requested for field work, related costs for analytical studies and for the support of graduate and undergraduate students. Mentoring and training of students is an essential target of this research. Besides a deep understanding of fundamental processes during rock evolution, students will gain experience in the development of a research program, the communication of research results, and the application of state-of-the-art analytical and computational techniques.

拟议的研究旨在定量理解岩石形成过程中的两个基本过程：成核和晶体生长。将研究这些过程的速率和机制，并将研究它们对岩石矿物质含量的大小和空间分布的影响。岩石中所有矿物谷物的尺寸和形状及其相互关系定义了岩石的质地。我的研究将为形成纹理的性质和速率提供新的见解。这很重要，因为岩石文本从根本上有助于散装岩石特性，例如电导率，强度以及固体土方对外力变化的反应方式。关于控制岩石文本形成和新发现的机制，只有知之甚少。我的研究重点是岩石变质过程中石榴石的结晶。之所以选择石榴石，是因为其化学成分反映了结晶过程中地壳中盛行的压力（P）和温度（T）条件。它还允许确定P和T随时间变化的速率。此信息对于理解山带的构造演变至关重要。模拟石榴石结晶的数值模型将通过在岩石中观察到的矿物化学和纹理进行开发和校准。在变质过程中化学平衡速率的量化率将取得进展。这是正确解释矿物分区和矿物组合所需的，这是如此之多的构造解释所取决于。要求资金进行现场工作，分析研究的相关费用以及研究生和本科生的支持。对学生的指导和培训是这项研究的重要目标。除了对岩石发展过程中的基本过程深入了解外，学生还将获得研究计划的制定，研究结果的交流以及最先进的分析和计算技术的经验。