metamorphic and igneous rocks here show extremely complex structure, which represents a geologic history told in many chapters.
metamorphic rock with interlocking quartz grains displaying a mosaic texture.
But igneous, metamorphic, and sedimentary rocks are all still rocks.
High temperatures and pressures at these depths cause the minerals to recrystallize, forming metamorphic rocks.
Granitic and metamorphic rocks, mostly gneiss and other metamorphic rocks injected by granitic rocks.
The three rock groups are igneous, sedimentary, and metamorphic rocks.
Extremely shiny, especially in strong sunlight, schist is a metamorphic rock formed under high temperatures and pressures.
Schist is a type of metamorphic rock that has undergone intense heat, pressure, and hot fluids.
Quite likely, this plays a critical role in explaining variations in metamorphic rocks.
The metamorphic rock may be heated enough to partially melt, but not completely.
British Dictionary definitions for metamorphic
metamorphic
/ˌmɛtəˈmɔːfɪk/
adjective
1.
relating to or resulting from metamorphosis or metamorphism
2.
(of rocks) altered considerably from their original structure and mineralogy by pressure and heat Compare igneous, sedimentary
Word Origin and History for metamorphic
adj.
1833 (Lyell) in the geological sense, in reference to rock whose form has been changed by heat or pressure, from metamorphosis + -ic. Earlier (1816) in non-technical sense "characterized by change."
metamorphic in Science
metamorphic
(mět'ə-môr'fĭk)
Zoology Relating to metamorphosis.
Geology Relating to rocks that have undergone metamorphism. Metamorphic rocks are formed when igneous, sedimentary, or other metamorphic rocks undergo a physical change due to extreme heat and pressure. These changes often produce folded layers or banding in the rocks, and they can also cause pockets of precious minerals to form. The folds and banding can be produced by incomplete segregation of minerals during recrystallization, or they can be inherited from preexisting beds in sedimentary rocks or preexisting layers in igneous rocks. The precious minerals can form as the result of recrystallization when the rocks undergoing metamorphism are subjected to changes in pressure and temperature.