Migmatite


Also found in: Dictionary, Wikipedia.
Related to Migmatite: mylonite, hornfels, phyllite, amphibolite, granulite, Hydrothermal metamorphism

migmatite

[′mig·mə‚tīt]
(petrology)
A mixed rock exhibiting crystalline textures in which a truly metamorphic component is streaked and mixed with obviously once-molten material of a more or less granitic character.

Migmatite

 

a rock consisting of metamorphic enclosing material with veins of granite. It is formed when liquid strata of granitic magma penetrate along the cleavage of metamorphic rocks. The granitic magma may form through the partial melting (anatexis) of metamorphic rocks under conditions of deep burial (regional metamorphism), when the molten rock is forced out of the unmelted metamorphic remainder. Many Precambrian migmatites were formed under such conditions. Migmatites located near large intrusive bodies of granitoids arose when granitic melt was injected into adjacent metamorphic rocks (injection gneiss). Migmatite is commonly found in ancient granite-gneiss complexes.

References in periodicals archive ?
The Yaounde series consist of strongly deformed meta-sedimentary rocks and migmatites (Nzenti et al, 1988)
00'E) near the town of Turku in southwestern Finland belong to the Turku Migmatite Complex of the southern Svecofennian Shist Belt.
The latter often contains migmatites or small bodies of enderbitic composition, otherwise plagioclase-potassium-feldspar leucosomes and granites prevail.
Examples are migmatites (rocks that were once partially molten and have retained part of their melt) and dykes (magma conduits that now contain solidified magma).
Within the drill logs high grade metamorphic minerals such as sillimanite and cordierite as well as zone of migmatite provide encouragement for graphitic flake development.
The garnetiferous biotite gneisses (khondalites) and the associated layered complex of garnetiferous quartzo-felspathic granulites (leptynites) and non-garnetiferous quartzo-felspathic granulites (alaskites) constitute an assemblage of metasediments injected by granitic materials, and recrystallised under deep-seated palingenetic conditions into a migmatite complex.
Joe Crowley's charge, winner of a bumper at the Listowel Festival, finished a close third to Migmatite at Clonmel, beaten just two lengths.
The Greater Himalayan Sequence (GHS) of the Bhutan Himalaya is a complex, highly deformed unit of gneiss and migmatite that has been intruded by leucogranite.
Quartz vein systems ranging from several inches to several feet thick occur around the perimeter of the migmatite contact with limestone or phyllite.
THE John Kiely-trained Migmatite took the featured Fishery Lane Hurdle at Naas yesterday under David Casey.