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A rock of both metamorphic and igneous origin that exhibits characteristics of both rock types and probably forms through the heating but not melting of rocks in the presence of abundant fluids.

[Greek migma, migmat-, mixture (from mignunai, to mix; see meik- in Indo-European roots) + -ite.]


(Geological Science) a composite rock body containing two types of rock (esp igneous and metamorphic rock) that have interacted with each other but are nevertheless still distinguishable
[C20: alteration of Swedish migmatit, from Greek migma mixture + -ite1]
References in periodicals archive ?
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).
Migmatite from the Skalka region (Czech Republic) was chosen as an experimental rock material.
However, recent discoveries of aquamarine in leucosomes within the migmatite indicate that the latter rocks may provide an alternative source of Be.
In this paper, we present new geochronological results of migmatite and granite rocks from the Sierra de Cachi, located in the Calchaqui Valleys at Salta, NW Argentina (Fig.
330-335 Ma), very close before the phase-related partial melting which led to the emplacement of migmatite components, aplites and pegmatites (Melleton et al.
The granite and the charnockite occur as intrusive bodies into the pre-existing migmatite rocks.
The Basement Complex rocks of Nigeria are composed predominantly of migmatite gneiss complex; slightly migmatised to unmigmatised paraschists and metaigneous rocks; charnockitic, older granite suites and unmetamorphosed dolerite dykes.
The ESSO drill logs report high grade metamorphic minerals such (sillimanite and cordierite) as well as zone of migmatite that provide encouragement for graphitic flake development.
Natural examples of such features can be easily found in migmatite terranes where small veins are located at their formation site, while larger veins have moved away and merged with others.
du Quebec a Chicoutimi) has included 272 color plates that reveal the beauty and complexity of these rocks, and also explains the microstructures, geochemical data and petrological processes involved with migmatite formation.