Rock strain fringes. Polarised light micrograph of strain fringes in a rock,also called pressure fringes. These are a type of microstructure formed by intense shear forces in deep-seated rocks. This example shows several pyrite crystals (opaque,black) in a phyllite host rock. The pyrite grains rolled over but remained rigid while the surrounding rock was deformed. Quartz,formed in the wake of the rotating grain,has been stretched out into a fibrous and curved shape. This image has been obtained using cross-polarised light (or 'crossed nichols'),which helps make the strain fringes visible | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 4957 px × 3770 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |