Question

What is original or preexisting rock called

Answer 1

Answer:

The original rock, or protolith, is subjected to heat and pressure which cause physical, chemical and mineralogical changes to the rock. Protoliths may be igneous, sedimentary or pre-existing metamorphic rocks. Metamorphic rocks are formed within the Earth's crust.

Answer 2

Answer:

The original rock, or protolith, is subjected to heat and pressure which cause physical, chemical and mineralogical changes to the rock. Protoliths may be igneous, sedimentary or pre-existing metamorphic rocks. Metamorphic rocks are formed within the Earth's crust