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.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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.

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References in periodicals archive

Tectono-metamorphic evolution and timing of the melting prosesses in the Svecofennian Tonalite-Trondhjemite Migmatite Belt: an example from Luopioinen, Tampere area, southern Finland.

Svecofennian metamorphic zones in the basement of Estonia/Eesti aluskorra Svekofennia moondevoondid

The Yaounde series consist of strongly deformed meta-sedimentary rocks and migmatites (Nzenti et al, 1988)

Interpreting gravity anomalies in south Cameroon, central Africa

Migmatite is dropping back from a mile and six furlongs to ten furlongs in very testing conditions.

Horse Racing: NALA DELIGHT; Halford's Princess is up for the Challenge

Hollister, "On the origin of C[O.sub.2]-rich fluid inclusions in migmatites," Journal of Metamorphic Geology, vol.

Origin and Evolution of the Ore-Forming Fluids in the Liyuan Gold Deposit, Central North China Craton: Constraints from Fluid Inclusions and H-O-C Isotopic Compositions

The average thickness of migmatite (13% of the volume) reaches 21 m.

Some properties and structure of the crystalline crust from superdeep drilling data (SG-3, SG-4, KTB)

Migmatite, a Giant's Causeway gelding bred by Michael Kinane, won the four-year-old maiden hurdle.

Horse Racing: Geraghty rides winner for his godmother; CLONMEL

Agasthyapura area falls east of the Sargur supracrustal complex, which forms a zone of high-grade metamorphic assemblages scattered within a migmatite gneissic complex (Fig.

Vermiculite mineralization associated with ultramafics in Agasthyapura area, Mysore dist., Karnataka state, India--a mineralogical study

The migmatite gneiss suites are mainly ca 2.8 to 2.0 Ga.

Compositional and petrogenetic features of schistose rocks of Ibadan area, southwestern Nigeria

The crystalline basement is mainly composed of metamorphosed rocks and tectonically structured Precambrian rocks (schist, gneiss, migmatite, quartzite) and granitic intrusions (Huhn et al., 2014).

Geospatial assessment of eco-environmental changes in desertification area of the Brazilian semi-arid region/Evaluacion geoespacial de los cambios ecoambientales en el area de desertificacion de la region semiarida brasilena

Caption: Figure 2: Geological map of the study area ([5] E: 1/1000000): 1, anatexite granite; 2, schist; 3, mica schist; 4, syenite; 5, tray basalt; 6, syn-tectonic granite (Monzonitic, discordant with biotite); 7, anatexite or migmatite with biotite); 8, embrechite gneiss; 9, Upper gneiss (grenatifere with two micas); 10, quartzite (Lom group, Mbalmayo-Bengbis, and Ayos); 11, Sedimentary formation of cretaceous; 12, upper mica schist with chlorite (Poli group); 13, low gneiss (with biotite, amphibole, pyroxene, sillimanite and hypersthene); 14, amphibolite (para- and ortho-: greenstones); 15, pelites; 16, post-tectonic granite (microgranite); 17, calcoalkaline orthogneiss.

Mapping of Deep Tectonic Structures of Central and Southern Cameroon by an Interpretation of Surface and Satellite Magnetic Data

A very similar setting exists in the Gander zone of northeastern Newfoundland, where SilurianDevonian granites are hosted by correlative sedimentary rocks of the Gander Group and paragneiss and migmatite of the Hare Bay Gneiss (Schofield and D'Lemos 2000).

Geochronology and lithogeochemistry of granitoid rocks from the central part of the Central plutonic belt, New Brunswick, Canada: implications for Sn-W-Mo exploration