In What Way Is Granite And Gneiss Related

Granite gneiss definition is a rock consisting of an orthogneiss or paragneiss having the composition of a granite.

In what way is granite and gneiss related.

Gneiss is a banded or foliated metamorphic rock of similar composition to granite. Granite is available in black grey orange pink white colors whereas gneiss is available in black brown pink red white colors. Other bands contain platy or elongate minerals with evidence of preferred orientation. A holocrystalline shale rock consisting like granite of quartz potash feldspar acid plagioclase and mica predominantly biotite.

Appearance of granite is veined or pebbled and that of gneiss is foliated. Paragneiss is gneiss derived from sedimentary rock such as sandstone. Minerals are seen arranged in bands in gneiss. It is very hard and used where granite would be used some gneisses are used as facing stone on buildings.

The rock itself is formed at crustal depths of 10 to 20 km at pressures of 10kb or more and temperatures between about 500 700 k so at depths where rock becomes quasi viscous high grade. Gneiss being a highly deformed crystalline metamorphic rock is commonly found in the cores of mountain ranges and in precambrian crystalline terranes. The nearly 40 major sedimentary rock layers exposed in the grand canyon and in the grand canyon national park area range in age from about 200 million to nearly 2 billion years old. Gneiss is a high grade metamorphic rock.

Gneiss ˈ n aɪ s is a common and widely distributed type of metamorphic rock gneiss is formed by high temperature and high pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks orthogneiss is gneiss derived from igneous rock such as granite. The geology of the grand canyon area includes one of the most complete and studied sequences of rock on earth. Most were deposited in warm shallow seas and near ancient long gone sea shores in western north america. This banding has alternating layers that are composed of different mi.

Gneiss is coarser than schist and has distinct banding. When we have to compare granite vs gneiss the texture color and appearance plays an important role in determining the type of rock. It is this banded appearance and texture rather than composition that define a gneiss. Not all gneiss is obtained from granite and there are also diorite gneiss biotite gneiss garnet gneiss and so on.

The mineral composition of both granite and gneiss is same but alteration of granite because of very high pressure and temperature leads to the formation of gneiss.