Answer:
On their mode of formation
Explanation:
The mode of formation of rocks is the basis of classifying them into the three main categories.
These categories are;
- Igneous rocks: they are formed by the cooling and solidification of molten magma.
- Sedimentary rocks: they are formed by the compaction and lithification of sediments.
- Metamorphic rocks are changed rocks formed when rocks are subjected to temperature conditions that alters their mineral composition.
