Whattype Of Rocks Are Gneiss Marble And Slate

It means a type of rock texture not a composition.

Whattype of rocks are gneiss marble and slate. Other bands contain platy or elongate minerals with evidence of preferred orientation. Non foliated metamorphic rocks such as hornfels marble quartzite and novaculite do not have a layered or banded appearance. Gneiss is a foliated metamorphic rock identified by its bands and lenses of varying composition while other bands contain granular minerals with an interlocking texture. Gneiss gneiss is a high grade metamorphic rock meaning that it has been subjected to higher temperatures and pressures than schist it is formed by the metamorphosis of granite or sedimentary rock.

The various types of foliated metamorphic rocks listed in order of the grade or intensity of metamorphism and the type of foliation are slate phyllite schist and gneiss figure 7 8. It is this banded appearance and texture rather than composition that define a gneiss. As already noted slate is formed from the low grade metamorphism of shale and has microscopic clay and mica crystals that have grown perpendicular to the stress. There are two basic types of metamorphic rocks.

The best known and most commonly seen metamorphic rocks are those produced by barrovian also called regional metamorphism. This type of metamorphic was created by regional metamorphism in which a sedimentary or igneous rock has been deeply buried and subjected to high temperatures and pressures. Foliated metamorphic rocks such as gneiss phyllite schist and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure.