Garnet is a common mineral at elevated pressures, and how it deforms plays an important role in the strength of lower crustal shear zones, subduction thrusts, and the mantle. Strong shape preferred orientations in elongate garnets at elevated temperatures and pressures attests to garnet's ability to deform through ductile mechanisms; however, how individual garnets deformed is frequently ambiguous or disputed. Garnet microstructures from the Morin shear zone and the Sulu ultra-high pressure terrane are revisited using fine-scale electron backscattered diffraction and wavelength dispersive spectroscopy mapping. The dominant deformation mechanism at each site is re-interpreted, and we show that garnet deformed through dissolution-precipitation creep at Sulu and through dislocation-assisted diffusion creep at Morin. These observations are integrated into a compilation of ductile deformation microstructures for garnet which reveals domains where dissolution-precipitation creep, recovery-accommodated dislocation creep (through subgrain rotation dynamic recrystallization), and dislocation-assisted diffusion creep dominate in P-T space. Garnet may deform through ductile deformation at temperatures as low as ~500 °C and deforms under low differential stresses in both eclogite and granulite facies conditions. The efficacy of deformation indicates that 1) garnet may not be the strongest phase in these environments, and 2) that at elevated temperatures, inclusion barometry may be affected by garnet's inability to maintain high differential stress.

石榴石是高压下的常见矿物，其变形如何在下地壳剪切带，俯冲推力和地幔的强度中发挥重要作用。在升高的温度和压力下，细长石榴石具有较强的形状偏好取向，这证明了石榴石通过延展性机制变形的能力；但是，单个石榴石如何变形经常是模棱两可的或有争议的。使用细尺度电子背散射衍射和波长色散谱图，对莫林剪切带和苏鲁超高压地层的石榴石微结构进行了重新研究。重新解释了每个部位的主要变形机制，我们发现石榴石通过苏禄的溶蚀-沉淀蠕变和莫林的错位辅助扩散蠕变而变形。PT空间。石榴石可能会在低至〜500°C的温度下通过延性变形而变形，并且在榴辉岩和花岗石相条件下，在低微分应力下也会变形。变形的有效性表明：1）石榴石在这些环境中可能不是最强的相； 2）在升高的温度下，石榴石无法保持高差应力可能会影响夹杂物气压。