We present microstructural and chemical analyses of chemically zoned and recrystallized plagioclase grains in variably strained samples of a naturally deformed anorthosite-leucogabbro, southern West Greenland. The recorded microstructures formed in the presence of fluids at mid-crustal conditions (620-640 A degrees C, 7.4-8.6 kbar). Recrystallized plagioclase grains (average grain size 342 mu m) with a random crystallographic orientation are volumetrically dominant in high-strain areas. They are characterized by asymmetric chemical zoning (An(80) cores and An(64) rims) that are directly associated with areas exhibiting high amphibole content and phase mixing. Analyses of zoning indicate anisotropic behaviour of bytownite plagioclase with a preferred replacement in the direction and along the (001) plane. In areas of high finite strain, recrystallization of plagioclase dominantly occurred by bulging recrystallization and is intimately linked to the chemical zoning. The lack of CPO as well as the developed asymmetric zoning can be explained by the activity of grain boundary sliding accommodated by dissolution and precipitation creep (DPC). In low-strain domains, grain size is on average larger and the rim distribution is not related to the inferred stress axes indicating chemically induced grain replacement instead of stress-related DPC. We suggest that during deformation, in high-strain areas, pre-existing phase mixture and stress induced DPC-caused grain rotations that allowed a deformation-enhanced heterogeneous fluid influx. This resulted in local plagioclase replacement through interface-coupled dissolution and precipitation and chemically induced grain boundary migration, accompanied by bulging recrystallization, along with neocrystallization of other phases. This study illustrates a strong interaction and feedback between physical and chemical processes where the amount of stress and fluids dictates the dominant active process. The interaction is a cause of deformation and external fluid infiltration with a result of strain localization and chemical re-equilibration at amphibolite facies conditions.