what are the features of primary rocks?
Igneous rocks are also known as primary rocks. Its chief features are:
- Since igneous rocks are formed due to the cooling and solidification of the magma, these rocks are hard and resistant to erosion.
- Water seeps in only through cracks and joints in the rocks. Thus these rocks are mostly not affected by chemical weathering.
- Igneous rocks are also called primary rocks as other rocks are basically formed out of igneous rocks.
- These rocks are usually fine grained with smooth texture or may have large crystals with coarse texture.
- Since these rocks are formed due to the cooling and solidification of the magma (lava), fossils are not found in these rocks.
- Igneous rocks can be further classified into extrusive igneous rocks or intrusive igneous rocks.