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Migmatite is a gneiss consisting of two or more distinct rock types, one of which has the appearance of an ordinary gneiss (the mesosome), and another of which has the appearance of an intrusive rock such pegmatite, aplite, or granite the (leucosome). The rock may also contain a melanosome of mafic rock complementary to the leucosome. [11]
The original name for this phenomenon was defined by Sederholm (1923) [24] as a rock with "fragments of older rock cemented by granite", and was regarded by him to be a type of migmatite. There is a close connection between migmatites and the occurrence of ‘explosion breccias’ in schists and phyllites adjacent to diorite and granite intrusions.
This page is intended to be a list of rock textural and ... Augen textured gneiss; Axiolitic texture; B ... see also schlieren and migmatite; E. Embayed ...
The following is a list of rock types recognized by geologists. There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type. Additionally, different classification systems exist for each major type of rock. [1]
Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...
Eilat stone; Epidosite; Glimmerite; Goldstone (glittering glass) Hawk's eye; Helenite (artificial glass made from volcanic ash) Iddingsite; Kimberlite; Lamproite; Lapis lazuli; Libyan desert glass; Llanite; Maw sit sit; Moldavite; Obsidian; Apache tears; Pallasite; Peridotite (also known as olivinite) Siilinjärvi carbonatite; Soapstone (also ...
Migmatite featuring felsic minerals, at Morton Gneiss Complex. Granitization is an old, and largely discounted, hypothesis that granite is formed in place through extreme metasomatism. The idea behind granitization was that fluids would supposedly bring in elements such as potassium, and remove others, such as calcium, to transform a ...
Granulite (Latin granulum, "a little grain") is a name used by petrographers to designate two distinct classes of rocks. According to the terminology of the French school it signifies a granite in which both kinds of mica (muscovite and biotite) occur, and corresponds to the German Granit, or to the English muscovite biotite granite. This ...