Abstract The relative strengths of constituent minerals in a deforming poly-mineralic rock depend on the grain size distributions of the various phases, the operating deformation mechanisms in those phases, and the topology of the microstructure. It is observed that more than one deformation mechanism operates, and the resulting constitutive relations (especially for calcite) are extremely variable. To explore such relations, deformation mechanism maps for each mineral are required together with mixing relations for multiple deformation mechanisms. We construct reference deformation mechanism maps for calcite and alkali-feldspars that are based on theoretical expressions for constitutive relations, together with experimental or molecular dynamic estimates of constitutive parameters. A thermodynamically based mixing relation is employed that enables bulk constitutive relations to be established for mixtures of mineral phases and deformation mechanisms with a range of grain sizes. This provides a basis for comparison and understanding of experimental results. We map out fields on deformation mechanism maps where switches in the relative strengths of calcite and quartz and of feldspar and quartz occur. We introduce the concept of geometrically necessary deformation mechanisms that minimise the energy of the system.

中文翻译：

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变形矿物相组合的相对强度：几何必要的变形机制

摘要 变形多矿物岩石中组成矿物的相对强度取决于各相的粒度分布、这些相中的操作变形机制以及微观结构的拓扑结构。据观察，有不止一种变形机制在起作用，由此产生的本构关系（尤其是方解石）变化很大。为了探索这种关系，需要每种矿物的变形机制图以及多种变形机制的混合关系。我们构建了方解石和碱长石的参考变形机制图，这些图基于本构关系的理论表达式，以及本构参数的实验或分子动力学估计。采用基于热力学的混合关系，能够为矿物相混合物和具有一定粒度范围的变形机制建立整体本构关系。这为比较和理解实验结果提供了基础。我们在变形机制图上绘制了方解石和石英以及长石和石英的相对强度发生变化的场。我们引入了几何必要变形机制的概念，以最小化系统的能量。我们在变形机制图上绘制了方解石和石英以及长石和石英的相对强度发生变化的场。我们引入了几何必要变形机制的概念，以最小化系统的能量。我们在变形机制图上绘制了方解石和石英以及长石和石英的相对强度发生变化的场。我们引入了几何必要变形机制的概念，以最小化系统的能量。