Subduction zone metamorphism

Subduction zone metamorphism is when rocks that form near the ocean floor get squished and pulled together like Play-Doh. As rocks get squashed together, the pressure and heat builds up and changes the rocks. This process is called metamorphism, and happens in places near mountains called subduction zones. Subduction zones form when a giant rock (called a tectonic plate) moves under another, and the rocks at the bottom get all smushed together! That pressure and heat can cause all kinds of change, like turning clay into marble or sandstone into quartzite.