Rock strain fringes. Polarised light micrograph of strain fringes in a rock, also called pressure fringes. These are a type of microstructure formed b


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.


Size: 4957px × 3770px
Photo credit: © DIRK WIERSMA/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: cross, cross-polarised, cross-polarized, crossed, crystal, crystalline, crystals, deformation, earth, forces, fringe, fringes, geological, geology, light, lm, micrograph, microscope, microscopy, microstructure, mineral, mineralogy, minerals, nichols, phyllite, plm, polarised, polarized, pressure, pyrite, quartz, rock, rocks, science, section, sectioned, shear, strain, stress