What is migmatite texture?
What is migmatite texture?
Migmatite – a high grade Barrovian metamorphic rock that has begin to fractionally melt. In appearance it looks like a gneiss intermixed with patches and splotches of phaneritic (coarse grained) igneous texture. This texture can be seen in the picture.
What is metamorphic rock texture?
Metamorphic texture is the description of the shape and orientation of mineral grains in a metamorphic rock. Metamorphic rock textures are foliated, non-foliated, or lineated are described below.
How was migmatite formed?
Most migmatites form when a solid metamorphic rock gets heated due to intrusion of magma (often granitic magma). The granite magma slowly cools and the heat flows into the surround country rock; now, the heat flows in and the metamorphic rock, initially ALL SOLID, heats up and begins to melt!
What is a migmatite in geology?
A migmatite is a metamorphic rock formed by anatexis that is generally heterogeneous and preserves evidence of partial melting at the microscopic to macroscopic scale. Migmatites represent the transition from metamorphic to igneous rocks in the rock cycle.
How are metamorphic rocks classified by texture?
Classification of Metamorphic Rocks. As with igneous and sedimentary rocks, metamorphic rocks are classified on the basis of texture (grain size, shape, orientation) and mineral composition. For example, greenschist (shale parent) and greenstone (mafic igneous parent).
What is schistose texture?
schistosity, mode of foliation that occurs in certain metamorphic rocks as a consequence of the parallel alignment of platy and lath-shaped mineral constituents. It reflects a considerable intensity of metamorphism—i.e., changes resulting from high temperatures, pressures, and deformation.
What is a migmatite quizlet?
Migmatite. a rock exhibiting both igneous and metamorphic characteristics. Such rocks may form when light-colored silicate minerals melt and then crystallize, while the dark silicate minerals remain solid. Minerology.
Why is migmatite only half metamorphic rock?
Migmatite is a composite rock found in medium and high-grade metamorphic environments. Migmatites form under extreme temperature and pressure conditions during prograde metamorphism, when partial melting occurs in metamorphic paleosome.
What kind of rock is a migmatite made of?
Migmatite. The migmatites of some Precambrian metamorphic terrains may be the result of this process. Migmatite also can form near large intrusions of granite when some of the magma is injected into the neighbouring metamorphic rocks.
What kind of environment does migmatite come from?
Migmatite is a composite rock found in medium and high-grade metamorphic environments.
Which is an example of a migmatite texture?
Schlieren textures are a particularly common example of granite formation in migmatites, and are often seen in restite xenoliths and around the margins of S-type granites.
How are migmatites formed in the metamorphic paleosome?
Migmatites form under extreme temperature and pressure conditions during prograde metamorphism, when partial melting occurs in metamorphic paleosome. Components exsolved by partial melting are called neosome (meaning ‘new rock’), which may or may not be heterogeneous at the microscopic to macroscopic scale.
