Is Migmatite foliated or Nonfoliated?
Metamorphic Rocks
| Foliated Textures | Non-foliated textures |
|---|---|
| Slate | Marble |
| Schist | Quartzite |
| Gneiss | Anthracite |
| Migmatite | Hornfels (gray rocks near bush) |
Is Migmatite a foliated metamorphic rock?
migmatite A coarse-grained, heterogeneous mixed rock consisting of: (a) a high-grade metamorphic component with a gneissose texture (see METAMORPHIC GRADE); and (b) an igneous component with a granite mineralogy and a foliated or unfoliated texture (see FOLIATION).
What type of metamorphism is Migmatite?
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 is Stromatic Migmatite?
The model explains the formation of stromatic migmatites through almost isochemical partial melting of paragneiss layers of different (more K-feldspar- or more plagioclase-rich) compositions. The K-feldspar-rich layers have near cotectic compositions and are transformed into leucosomes at relatively low temperatures.
What is foliated and Nonfoliated?
Foliated metamorphic rocks exhibit layers or stripes caused by the elongation and alignment of minerals in the rock as it undergoes metamorphism. In contrast, nonfoliated metamorphic rocks do not contain minerals that align during metamorphism and do not appear layered.
What is the difference between migmatite and gneiss?
Mafic minerals are generally darker in color, often black, brown, or dark green. Migmatites actually look very similar to a related rock: gneiss. Gneisses also contain alternating light and dark layers which result under high-pressure and high-temperature conditions.
What type of rock is Migmatite?
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.
What is a Migmatite in geology?
Migmatites are heterogeneous, medium- to high-grade metamorphic rocks with at least one component formed by partial melting. As migmatites form under P–T conditions common in the middle and lower crust, they are widespread and likely to be encountered in the field.
Is Muscovite foliated or Nonfoliated?
html. TEXTURES Textures of metamorphic rocks fall into two broad groups, FOLIATED and NON-FOLIATED. Foliation is produced in a rock by the parallel alignment of platy minerals (e.g., muscovite, biotite, chlorite), needle-like minerals (e.g., hornblende), or tabular minerals (e.g., feldspars).
What is foliation in a metamorphic rock?
Foliated Metamorphic Rocks: Foliation forms when pressure squeezes the flat or elongate minerals within a rock so they become aligned. These rocks develop a platy or sheet-like structure that reflects the direction that pressure was applied.
What is migmatite used for?
Migmatites have an attractive appearance, often being marked with irregular small stripes or patches of contrasting shades ranging from almost white to dark grey, and are widely used as building stone, sometimes being polished for ornament.