Review Questions for Chapter 22: A Classification of Metamorphic Rocks
1. What do a slate and a phyllite have in common?
How are they distinguished from one another?
What is responsible for the difference?
2. What does a schist have in common with a slate and phyllite?
3. How does schistosity differ from cleavage?
4. What distinguishes a gneiss from a schist?
5. How might you tell an orthogneiss from a paragneiss?
6. What does a cataclasite have in common with a mylonite?
In what way do they differ?
7. What does a calc-silicate granofels and a skarn have in common?
In what way do they differ?
8. What is a preferred name for a quartz granofels?
9. What would you name the following rocks?
a. An incipiently metamorphosed siltstone in which the original texture and mineralogy is largely
intact
b. A rock with good cleavage and looks like a shale but rings when you hit it with a hammer
c. A rock composed of chlorite and actinolite with a pronounced alignment of the minerals
d. A rock dominated by sub-equal amounts of hornblende and plagioclase with a random fabric
e. A rock with the same mineralogy as the previous rock, but with an obvious foliation
f. A rock containing quartz, orthoclase, plagioclase, and biotite, with a discontinuous
metamorphic banding of dark and light layers (include an indicator of composition in your
name)
g. The same rock as the previous one but with large eye-shaped grains of orthoclase in a finer
matrix
h. A rock composed of coarse calcite grains with a slight foliation
i. A rock composed of 20% biotite, 35% quartz, 15% muscovite, 5% plagioclase, and 10%
garnet, with good foliation
j. A slate-like rock with a satiny sheen on the cleavage and 5-mm-sized ovoid blobs of cordierite
k. A fine-grained rock with random fabric and splintery fracture
l. A green clinopyroxene granofels with red garnets
m. A glaucophane, albite, epidote rock with a distinct fabric
n. A tremolite, diopside grossular, carbonate granofels
o. A gneissic rock containing feldspar, quartz, and orthopyroxene