Physical Classification of Rocks // Rock Types //

Physical Classification of Rocks

Based on the physical structures of rocks, the rocks are classified into stratified rocks, unstratified rocks, and foliated rocks.

Stratified rocks
Stratified rocks are those have layered structures.

These rocks process planes of cleavage or stratification.
These rocks can be easily split up along the plane.
Sedimentary rocks are mostly stratified rocks.
The examples of stratified rocks are sandstones, limestones, slate etc.

Unstratified rocks
These rocks are not stratified.
These rocks are crystalline granular or compact granular.
Unstratified rocks are most of igneous rocks of volcanic activity and sedimentary rocks affected by movement of the earth.
The examples of unstratified rocks are granite, marble, trap etc.
Foliated rocks
Foliated rocks have a tendency to split along a definite direction only.
The direction is need not be parallel as in case of stratified rocks.
Metamorphic rocks are commonly foliated rocks.
The examples of foliated rocks are gneiss, phyllite, schist etc.

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