Fig. 9
From: Lower-crustal earthquakes in southern Tibet are linked to eclogitization of dry metastable granulite
Schematic illustration of the self-organization process of fault zones in metastable granulite deformed in eclogite stability field. a Initial microstructure with clean grain boundaries and mineral separation among Plg, Cpx, and Qtz. b Reactions (1) and (2) occur along the Plg + Cpx (red dashed lines) and Plg + Qtz interfaces (black dashed lines). Within Plg grains Reaction (3) takes place (white dashed lines). These are the nuclei of NRBs. As reactions proceed, stress concentration sites increase along interfaces, initializing micro-cracks propagating inward individual grains (thin red lines). c NRBs grow within Plgs grains and along mineral interfaces, causing shear displacements in Plg grains and grain boundary sliding. Micro-cracks occur in Cpx and Qtz grains. d NRBs and micro-cracks connect forming larger fault zones (black lines)
