Re-equilibration processes in grain-internal domains: The interrelation of mineral reactions and deformation during metamorphism (TP14)

利用颗粒内部的搁浅反应研究了控制变质岩再平衡过程的参数。我们的重点是矿物寄主/包裹体的排列，它们受到环境条件(P、T、X、应力)不同程度变化下的再平衡的影响。利用来自东部阿尔卑斯山奥斯特罗阿尔卑斯基底单元的可用样品，我们打算比较表现为基本封闭系统的包裹体结构域和那些可以与基质进行物质交换的开放包裹体结构域。将特别关注矿物反应、化学物质传输和变形的相互关系。限制微裂隙、(亚)晶界和相界等结构非均质性对材料流变学、微结构发展和矿物反应的影响，有望为复杂反应体系在构造载荷下的行为提供新的信息。预期的研究依赖于微观结构、结构和矿物成分的表征，重点是高分辨率分析技术(电子微探针分析、扫描电子显微镜、电子背向散射衍射、阴极发光、双聚焦离子束技术)。这些方法将应用于宿主/包裹体边界、宿主内部反应前沿以及应变和非应变宿主结构域中物质传输的潜在通道。最先进的材料表征将为相平衡的热力学建模、扩散建模和力学建模提供基础，以便识别和量化变质过程中的控制参数及其相互作用。

Stranded reactions in grain interiors are used to study the parameters controlling re-equilibration processes in metamorphic rocks. We focus on mineral host/inclusion arrangements, which were affected by re-equilibration under changing ambient conditions (P, T, X, stress) to variable degree. Using available sample material from Austroalpine basement units in the Eastern Alps, we intend to compare inclusion-domains that behaved as essentially closed systems with those which were open for material exchange with the matrix. Special focus will be placed on the interrelation of mineral reactions, chemical mass transport and deformation. Constraining the influence of structural heterogeneities such as microfractures, (sub)grain boundaries and phase boundaries on material rheology, microstructure development and mineral reactions is supposed to yield new information on the behaviour of complex reactive systems under tectonic load. The intended research relies on the characterization of microstructures, textures and mineral compositions with an emphasis on high resolution analytical techniques (electron microprobe analysis, scanning electron microscopy, electron backscatter diffraction, cathodoluminescence, dual focused ion beam technique). These methods will be applied to host/inclusion boundaries, host internal reaction fronts and potential passageways for material transport in strained and unstrained host domains. State of the art material characterization will provide the basis for thermodynamic modelling of phase equilibria, diffusion modelling and mechanical modelling in order to identify and quantify the controlling parameters during metamorphism and their interplay.