Localisation of ductile and brittle shear zones along the Szentlőrinc-1 well in the Mecsekalja Zone using quartz microstructural and well-log data

摘要: Quartz is among the most common minerals in Earth’s crust and stable within a wide range of temperature pressure conditions. As its microstructure sensitive to different deformation mechanisms, quartz may present information about structural evolution many rock types. The Szentlőrinc-1 well with drill cuttings brought surface from approximately 2 km depth provides an exclusive chance investigate shear zone beneath. cutting collection includes only few small grains, more than 80 % material consists tiny (<1 mm) single grains. In this study, three microstructurally extreme grain types were separated during microscopic analysis: grains undulose extinction (U), subgrains (S), recrystallized (R). Moreover, numerous transitional measured, which represent combinations above extremes. characterisation microstructures along whole enables identification localisation ductile zones inside crystalline complex. This was combined well-log data, could provide brittle deformation. Using these logs, can be localised well. When comparing depths extensions deformed horizons, coincidence becomes clear. behaviour suggest two schemes: it caused by primarily evolved softened regions, or described detachment fault model.