What is an example of a low grade metamorphic rock?

What is an example of a low grade metamorphic rock?

Typical low-grade metamorphic minerals are albite, muscovite, chlorite, actinolite and talc. Slate is an extremely dense, fine-grained metamorphic rock form under low-grade regional metamorphism emerged from pelitic sedimentary rocks such as shales and fine-grained tuffs (Table 6.1).

How are low grade metamorphic rocks formed?

Responses of Rock to Increasing Metamorphic Grade Slate – Slates form at low metamorphic grade by the growth of fine grained chlorite and clay minerals. The preferred orientation of these sheet silicates causes the rock to easily break along the planes parallel to the sheet silicates, causing a slatey cleavage.

Is gneiss a low grade metamorphic rock?

Slate is a product of low grade metamorphism (not terribly great burial temperatures and pressures are required). Schist and gneiss are produced by medium to high grade metamorphism. In some cases gneisses are produced by higher grade metamorphism than schists.

Which is the proper order of metamorphic rocks from low grade to high grade?

Along this route the degree of metamorphism gradually increases from sedimentary parent rock, to low-grade metamorphic rock, then higher-grade metamorphic rock, and eventually the igneous core. The rock sequence is sedimentary rock, slate, phyllite, schist, gneiss, migmatite, and granite.

Is granite a low grade metamorphic rock?

Some examples of non-foliated metamorphic rocks are marble, quartzite, and hornfels. Marble is metamorphosed limestone….7.2 Classification of Metamorphic Rocks.

What is the highest grade of metamorphic rock?

Gneiss
Gneiss, the highest grade metamorphic rock, contains bands of easily visible quartz, feldspar, and/or mica.

What are characteristics of metamorphic rocks?

Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat and/or pressure within the Earth’s crust. They are crystalline and often have a “squashed” (foliated or banded) texture.

What are the example of metamorphic rocks?

Common metamorphic rocks include phyllite, schist, gneiss, quartzite and marble. Foliated Metamorphic Rocks: Some kinds of metamorphic rocks — granite gneiss and biotite schist are two examples — are strongly banded or foliated.

Which rock has the highest metamorphic grade?

Gneiss , the highest grade metamorphic rock, contains bands of easily visible quartz, feldspar , and/or mica. From left to right: slate, phyllite, schist , gneiss. More metamorphic rocks. Click on each photo for a larger image.

What does the metamorphic grade of a rock tell you?

Metamorphic grades describe rocks on a relative scale from less altered to more altered. In pelitic (fine-grained sedimentary) rocks, the appearance of index minerals indicates the degree of alteration. Index minerals are helpful in determining isograds and metamorphic zones.

What are the characteristics of high grade metamorphic rocks?

High grade metamorphic rock will appear very solid. All the minerals will be melted and compressed together. Quartzite is a case where the quartz grains of sandstone are compressed to the point that they fuse together around their margins.

What are metamorphic rocks are classified according to?

Metamorphic Rocks. Most metamorphic rocks are classified according to grain size , with the coarsest grain sizes reflecting the highest temperatures (or grade) of metamorphism. The lowest grade metamorphic rock type is slate, which consists of crystals that are generally too fine to see. The next higher grade rock, phyllite, contains grains that are still too small to see easily, but are coarse enough to catch light and so impart a sheen to the rock.