The arrow which is labeled A points from igneous rock to metamorphic rock.
There are three types of Rocks:
1. Igneous Rock
2. Metamorphic Rock
3. Sedimentary Rock
Rock cycle:
Rock cycle is the process that describes the transition between these three types of rocks. Each type has its own form and its own equilibrium condition. The rock type alters when it is pushed out of its equilibrium conditions.
Transition of Igneous rock to Metamorphic rock:
Igneous rock forms when magma cools down. The transition of Igneous Rock to Metamorphic Rock is a result of a process called Metamorphism. Metamorphism is the alteration in the structure of rock as a result of certain heat and pressure conditions. Inside Earth heat comes from pressure. Heat with pressure does not melt the rock but it bakes the rock. Baking is not melting but it changes the shape of the rock while it is still solid. It actually forms crystals. Because the rock changes its structure, it is called Metamorphic Rock.
