Rocks
Definition– a rock can be defined as an aggregate of minerals.
The solid part of the earth’s crust are called rocks. Rocks are classified in three main types depending on the process of their formation
- Igneous rocks
- Sedimentary rocks
- Metamorphic rocks
Igneous rocks
- Formed due to cooling, solidification and crystallization of hot and molten magma.
- They are called as primary rocks as all the other rocks are formed directly or indirectly from igneous rocks.
- They are hard, granular and crystalline rocks, less affected by chemical weathering.
- Moreover it does not have any fossil or does not form any strata or layers of lava examples of igneous rocks granite, basalt, gabbro, pegmatite and peridotite.
Sedimentary rocks
It is formed due to the aggregation and compaction of sediments derived from the older rocks, plants, animals and contains fossil plants How do you
The sedimentary rocks can be classified on the basis of the nature of the sediments: mechanically, chemically and organically formed drugs
Metamorphic rocks
- These are the changed form of igneous and sedimentary rocks.
- These are the rocks which change in either form or composition without disintegration.
- Already found metamorphic rocks are metamorphic and this process is called metamorphosis.
- The agents of metamorphism are : heat, compression and solution.
Original rocks – Metamorphic rocks
Sandstone – Quartzite
Limestone – Marble
Shale and mudstone – slate
Granite – Gneiss
Coal – Graphite coal
Clay – slate
