Geologists classify metamorphic rocks primarily according to
A)whether they are foliated or nonfoliated.
B)whether they contain pseudomorphs.
C)the percentage of silica.
D)the size of their crystals

Question

Quizplus · Accepted Answer

Geologists classify metamorphic rocks primarily according to whether they are foliated (have a layered structure) or nonfoliated (have a more uniform structure). This is based on the presence or absence of preferred orientation of minerals within the rock, which is related to the amount of pressure and temperature the rock was subjected to during the metamorphic process. Pseudomorphs (minerals that have replaced other minerals but retained the shape of the original mineral) and crystal size are secondary factors used in classification. The percentage of silica is not typically used to classify metamorphic rocks.

Geologists Classify Metamorphic Rocks Primarily According to