Here's why:
* Metamorphism: This term refers to the process where existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat and pressure deep within the Earth's crust.
* Heat: The heat can come from the Earth's internal heat, or from nearby magma intrusions.
* Pressure: This is the force exerted on the rock from the weight of overlying rocks.
The changes that happen:
* Mineralogical changes: The minerals within the original rock can recrystallize or react to form new minerals, giving the metamorphic rock a different composition.
* Textural changes: The original texture (grain size, arrangement of grains) can change, leading to features like banding, foliation, or other distinctive patterns.
Examples of metamorphic rocks:
* Marble: Formed from limestone or dolostone by heat and pressure.
* Slate: Formed from shale by low-grade metamorphism.
* Gneiss: A high-grade metamorphic rock with a banded appearance.
Let me know if you want to know more about metamorphic rocks!
