Why is metamorphism not reversible?

Answer 1

Metamorphism is not reversible because it involves significant changes in mineral composition and structure due to high temperature and pressure over geological time. These conditions can lead to the formation of new minerals that may not exist in the original rock, and the original rock's texture is often altered. Additionally, the process can cause the loss of volatile components, which cannot be regained, thus making it impossible to revert to the original state. Once metamorphic rocks form, the specific conditions that created them cannot be duplicated exactly in reverse.