How is a metamorphic rock formed?

How is a metamorphic rock formed?

• A. From cooling lava.
• B. From sediments compacted.
• C. From minerals laid down in layers.
• D. When existing rocks are altered by heat and pressure deep underground.

Answer: (D)

Metamorphic rocks form when existing rocks are transformed by heat and pressure deep underground. The rock doesn’t melt; instead the minerals rearrange and recrystallize, which can change the rock’s texture and mineral makeup. Under intense heat and pressure, minerals may align to create layered or banded textures, a process called foliation. This transformation happens over long periods as rocks are buried deeper or heated by nearby magma. Examples include slate formed from shale and marble formed from limestone. For contrast, igneous rocks come from molten rock that has cooled and solidified, while sedimentary rocks form from particles that are deposited, compacted, or cemented together.

Metamorphic rocks form when existing rocks are transformed by heat and pressure deep underground. The rock doesn’t melt; instead the minerals rearrange and recrystallize, which can change the rock’s texture and mineral makeup. Under intense heat and pressure, minerals may align to create layered or banded textures, a process called foliation. This transformation happens over long periods as rocks are buried deeper or heated by nearby magma. Examples include slate formed from shale and marble formed from limestone. For contrast, igneous rocks come from molten rock that has cooled and solidified, while sedimentary rocks form from particles that are deposited, compacted, or cemented together.