Quantitative structural analyses and numerical modelling of ...

3. Quantitative analyses of metamorphic microstructures 36Figure 3.6: Example of digitized microstructures originated from heterogenous decompositionof alkaline feldspar due to increase of temperature.strain energy in the aggregate. Such a strain energy is driven by decompression associatedwith slight cooling of perthitic aggregate and leads to development of particularmicrostructure which reduces both strain and surface energies of the aggregate. ThePolyLX played decisive role in the characterizing the process and it shows that the microstructurereveals highest nucleation density compared to growth in conjunction withhighest possible regular grain distribution which was recorded in metamorphic rocks sofar. This microstructure showed to be a precursor for granulite mylonitic fabric. ThePolyLX allows tracking the microstructure evolution of the rock and helps to define firstgrain boundary sliding diffusional process replaced subsequently by dislocation creepflow at lower temperatures.3.1 Perspectives for numerical modeling of deformationmicrostructures and their quantificationPolyLX method revealed high applicability in microstructural analysis thanks to its versatileand modular character allowing large amount of applications in paleopiezometry,crystal size distribution, grain contact frequencies and deformation mechanisms studiesaccompanied with texture analyses (Fig. 3.7). The potential is therefore in further useof the method in a variety of microstructural studies which can be combined with kineticgrow/nucleation models if the thermal history is known. For that purpose a coupling