- change in the mineralogical, structural, or textural composition of rocks under pressure, heat, chemical action, etc., which turns limestone into marble, granite into gneiss, etc.
The process by which rocks are altered in composition, texture, or internal structure by extreme heat, pressure, and the introduction of new chemical substances.
Origin of metamorphismmetamorph(ic) + –ism.
- (geology) The process by which rocks are changed into other forms by the application of heat and/or pressure.
- (zoology) The process by which insects development through life stages -- as, for example, those of embryo, larva, pupa and imago. The life cycle of the butterfly is one of complete metamorphosis, in which the embryo grows within the egg, hatches into the larval stage caterpillar, enters the pupal stage within its chrysalis, and finally emerges as an adult butterfly imago.