1. Metamorphic rocks: These rocks are formed when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are subjected to intense heat and pressure deep within the Earth's crust. The heat and pressure cause the minerals within the rock to recrystallize, changing their texture and sometimes even their mineral composition. Examples of metamorphic rocks include marble (formed from limestone), slate (formed from shale), and gneiss (formed from granite).
2. Contact metamorphic rocks: This is a specific type of metamorphic rock formed when existing rocks come into contact with a heat source, such as an igneous intrusion (magma or lava). The heat from the intrusion "bakes" the surrounding rocks, transforming them into metamorphic rocks.
So, while both metamorphic rocks and contact metamorphic rocks are formed by the transfer of heat, contact metamorphic rocks are a subset of metamorphic rocks specifically formed by the contact with a heat source.
