Preexisting rock that is subsequently altered to form a metamorphic rock is termed a ________.
A)xenolith
B)source rock
C)protolith
D)phenocryst

Question

Quizplus · Accepted Answer

The term protolith refers to the preexisting rock that is later altered to form a metamorphic rock. Xenolith is a type of rock that is foreign to the igneous rock in which it is found. Source rock is a general term used to describe the rock that forms a petroleum reservoir. Phenocryst is a type of crystal that is larger than the matrix in which it is found in an igneous rock.

Preexisting Rock That Is Subsequently Altered to Form a Metamorphic