Answer:
Evidence of metamorphism can be indicated by <u>flat, horizontal</u> layers within the rock.
Explanation:
Metamorphic rocks refer to rocks that are modified with heat or pressure, which change their physical and chemical properties. The main reason behind this modification is the rearrangement of the mineral crystals, which occurs due to their response to the previously-mentioned properties of heat and pressure.
There could be different types of evidence of metamorphism. However, the main evidence can be indicated by the presence of <u>flat, horizontal</u> layers within the rock, also known as foliation, a process that occurs when the pressure squeezes the minerals, leading to a flat, horizontal layer. Then, scientists could analyze the composition of these layers to identify minerals or even fossils within it.
