Here's a breakdown:
* Metamorphism is the process where existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, or chemically active fluids. This changes the rock's mineral composition, texture, and sometimes even its chemical composition.
Here's why other options aren't the correct answer:
* Weathering: This breaks down rocks into smaller pieces, creating sediment. It doesn't change the rock's mineral composition fundamentally.
* Erosion: This moves weathered rock fragments, but it doesn't change the rock's composition.
* Deposition: This is the process of sediments settling and accumulating. While it leads to sedimentary rocks, it doesn't create metamorphic rocks.
* Cooling and crystallization: This is how igneous rocks form. It doesn't describe the transformation of pre-existing rocks into metamorphic rocks.
In short, metamorphism is the unique process that transforms existing rocks into metamorphic rocks.
