Question

What distinguishing features describe metamorphic rocks

Answer 1

Answer:

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.

Slate

Slate

Slate is made of fine-grained interlocking crystals which lie flat in the same direction, known as the cleavage direction, along which the rock easily splits.

Schist

Schist

Schist is made of medium-grained interlocking crystals. Its shiny appearance is due to the mineral mica. Crystals line up to give the rock wrinkly layers – this is called foliation.

Gneiss

Gneiss

Gneiss is made of coarse-grained interlocking crystals. Crystals line up in pale and dark layers to give the rock a banded texture.

Marble

Marble Marble (metamorphosed limestone) is made of calcium carbonate (fizzes with acid). It has medium-grained Interlocking crystals with no alignment.

Bottom curves

Answer 2

Metamorphic rocks -

• Metamorphic rocks are the rocks that transform from one existing type of rock to a new type of rock from the process known as metamorphosis.

• The pre-existing rock undergoes temperature and pressure changes or any kind of chemical or physical changes.

Distinguishing features of metamorphic rocks -

• Metamorphic rocks are formed from other rocks like igneous, sedimentary, and sometimes even metamorphic rocks.
• The processes which undergo the formation of metamorphic rocks are foliation and lineation.
• These rocks can be easily distinguished from other rocks by their mineral constitution and specific textures which can only be seen in this type of rock.
• They are crystalline in nature and their texture is often been described as the “squashed” texture.