What are the types of metamorphic zones?
The sequence of zones now recognized, and the typical metamorphic mineral assemblage in each, are:
- Chlorite zone. Pelitic rocks are slates or phyllites and typically contain chlorite, muscovite, quartz and albite.
- Biotite zone.
- Garnet zone.
- Staurolite zone.
- Kyanite zone.
- Sillimanite zone.
Which are the three zones of metamorphism?
Commonly we call then low, middle, and high grade metamorphism, but geologically they are the greenschist facies, amphibolite facies, and granulite facies. Everything in Barrovian metamorphism is in reference to these three facies, or conditions of metamorphism.
How do you find the metamorphic zone?
The first or last appearance of an index mineral (the place where a metamorphic reaction is observed) forms an easily recognizable isograd. A metamorphic zone is the region between two such easily recognizable isograds. Often they are named for the most characteristic index mineral of the zone.
What are the grades of regional metamorphism?
In light of different metamorphism degrees, regional metamorphism can be divided into three zones of shallow, intermediate, and deep metamorphic, and the corresponding metamorphic grade is low, intermediate, and high grade.
What is the highest metamorphic grade?
Gneiss
Gneiss, the highest grade metamorphic rock, contains bands of easily visible quartz, feldspar, and/or mica.
What are the 6 types of metamorphism?
Top 6 Types of Metamorphism | Geology
- Type # 1. Contact or Thermal Metamorphism:
- Type # 2. Hydrothermal Metamorphism:
- Type # 3. Regional Metamorphism:
- Type # 4. Burial Metamorphism:
- Type # 5. Plutonic Metamorphism:
- Type # 6. Impact Metamorphism:
What grade of metamorphism is sillimanite?
Sillimanite from a variety of high-grade metamorphic rocks contains from 0-13 to 1-82 weight per cent Fe2O3 and less than 0-1 weight per cent TiO2. The iron is trivalent and substitutes for Al only.
What is the difference between low grade and high-grade metamorphic rocks?
Low-grade metamorphic rocks tend to be fine-grained (the newly formed metamorphic mineral grains that is). High-grade metamorphic rocks tend to be coarse-grained. Foliation in metamorphic rocks is related to the orientation of the applied stresses and not the original sedimentary or earlier metamorphic structures.
What metamorphic grade is Garnet?
Garnet-Mica Schist
| Type | Metamorphic Rock |
|---|---|
| Color | Shiny, medium gray |
| Miscellaneous | Small-sized dark red-brown garnets on foliation surfaces |
| Metamorphic Type | Regional |
| Metamorphic Grade | Middle Grade (Middle P – Middle T) |
What is the difference between foliated and Nonfoliated?
Foliated rocks are types of metamorphic rock that have parallel bands of grain. Non-foliated rocks are types of metamorphic rock that have no arrangement or bands of grain. Marble is a type of metamorphic rock that originates from limestone.
What is metamorphic grade?
(Metamorphic grades refer to the degree and intensity of the metamorphism: they are determined by the pressure and temperatures to which the rock has been subjected.) Such areas are generally referred to as metamorphic core complexes.
What is the difference between high-grade and low grade metamorphism?