Chapter 25, Problem 20RQ

Distinguish between foliated and nonfoliated metamorphic rocks.

To determine

The difference between foliated and nonfoliated metamorphic rocks.

Answer to Problem 20RQ

The foliated rocks have a layered appearance, whereas nonfoliated metamorphic rocks have a uniform appearance.

Explanation of Solution

The difference between foliation rocks and Nonfoliated rocks are shown below:

	Foliation rocks	Nonfoliated rocks
1	Foliation rocks have a layered appearance which occurs when rocks are under high pressure.	Nonfoliated rocks show uniform appearance.
2	Foliation is developed due to high pressure and temperature both.Both are necessary	Nonfoliated rocks can form either due to high pressure or high temperature.
3	Examples are granite, quartz and feldspar.	Examples are marble and quartzite.

Conclusion:

Therefore, the foliated rocks have a layered appearance whereas nonfoliated metamorphic rocks have a uniform appearance.