Why are igneous rocks called primary rocks?

1 Answer
Nov 5, 2015

As igneous rocks are formed from magma and begin the rock cycle, they are called primary rocks.


Igneous rocks are created from the cooling of molten magma/lava. All other rocks are derived from them, which is why you will also find them referred to as parent rocks on occasion.

This image is a pretty good illustration of the rock cycle:


As you can see, it starts with magma #-># igneous rock. From there, all other manner of rocks can be made.