Geological Classification of Rocks
On the basis of geological occurrence, rocks are classified into three categories:
- Sedimentary Rocks
- Igneous Rocks
- Metamorphic Rocks
Sedimentary Rocks
Rocks formed due to deposition of minerals one over another due to action of water, wind, and other natural agents is called sedimentary rocks.
- Sandstone
- Limestone
- Shale
- Claystone
- Conglomerate
- Dolomite
Igneous Rocks
Rocks formed due to volcanic action when magma or lava cools down and solidifies is called igneous rocks
There are two types of igneous rocks:
Plutonic Rocks
Igneous rocks which cools down and solidifies inside the earth surface is called plutonic rocks
- Granite
- Pegmatite
- Gabbro
Volcanic Rocks
Igneous rocks which cools down and solidifies outside the surface of earth is called volcanic rocks.
- Basalt
- Obsidian
- Pumice
Metamorphic Rocks
Rocks formed due to metamorphosis is called metamorphic rocks.
Metamorphosis of rocks is change in nature under the action of heat, pressure, temperature, chemical on sedimentary and igneous rocks is called metamorphic rocks
- Limestone-Marble
- Sandstone-Quatrzite
- Granite-Gneiss
- Shale-Slate