what is the rock cycle? why do we call it a cycle?
As this happened, a cycle of events began to be put into place that causes changes in the rocks that exist on the earth. This cycle is known as the rock cycle. The rock cycle is a model used to describe the creation, alteration, and destruction of the rocks that form from magma. It is important to note that new matter is never created on the earth. All the matter that the earth contains was present when the earth formed and still is here today.