____ is the lowest-grade rock in progressive metamorphism.
A) Schist
B) Gneiss
C) Marble
D) Slate
E) Phyllite

Question

Quizplus · Accepted Answer

Slate is the lowest-grade rock in progressive metamorphism. It is formed from the metamorphism of shale or mudstone. As the rocks undergo metamorphism, heat and pressure cause the minerals to recrystallize and align, forming a fine-grained rock with a layered structure. Slate can further metamorphose into phyllite, schist, and eventually gneiss with increasing grade of metamorphism.

____ Is the Lowest-Grade Rock in Progressive Metamorphism