pressure fringe
pressure fringe A growth of fibrous quartz, calcite, chlorite, or muscovite, normal (or sometimes parallel) to the face of a porphyroblast (usually pyrite or magnetite) in a regional metamorphic rock. During metamorphism and deformation minerals dissolved from the region of high pressure, where the matrix is squeezed against the crystal, are redeposited in the pressure shadow zone at the side of the crystal. The minerals nucleate on the face of the prophyroblast and regrow in a fixed crystallographic orientation with respect to the edge of the large porphyroblast. This results in the straight fibres which often intersect at segment junctions. Where the porphyroblast is rotated during the metamorphic event the pressure-fringe minerals grow as curved fibres, thus tracing the stages of detachment between porphyroblast and matrix.
More From encyclopedia.com
Osmotic Pressure , Skip to main content
osmotic pressure Vapor Pressure , Vapor pressure is the pressure that occurs because of the formation of vapor, or gas, from a liquid or solid. Within chemistry, this pressure general… Barometers , A barometer is an instrument for measuring atmospheric pressure. Two kinds of barometers are in common use, a mercury barometer and an aneroid barome… Pressure , Pressure is the amount of force applied to a given area. Pressure is expressed in units such as pounds per square inch in the English system or newto… Pressure Melting , pressure melting The melting of ice in response to stress. It comes about because the freezing temperature of water falls as pressure increases, at a… Broasting , BROASTING. "Broasting" is a trademarked term for frying chicken, potatoes, and other food in a pressure cooker using equipment and ingredients obtain…
You Might Also Like
NEARBY TERMS
pressure fringe