Page 226 - Laboratory Manual in Physical Geology

C. Analyze the rock sample in FIGURE 7.3 . The parent rock for this metamorphic rock had flat layers that were folded during

metamorphism. Describe a process that could account for how this rigid gneiss was folded without breaking during regional
metamorphism. ( Hint : How could you bend a brittle candlestick without breaking it?)

D. Analyze this metamorphic rock sample using the
classification chart in FIGURE 7.16 .

1. Is this rock foliated or nonfoliated?

2. Notice that the rock consists mostly of muscovite but

also contains scattered garnet crystals. What is the
name for this kind of texture?
Garnet
Garnet

3. What is the name of this metamorphic rock?
Muscovite
Muscovite
Muscovite

4. What was the likely parent rock (protolith)?

1
E. Analyze this metamorphic rock sample using the

classification chart in FIGURE 7.16 . Plagioclase

(white)

1. Is this rock foliated or nonfoliated and how can you
tell?

2. What is the name of this metamorphic rock?

3. What was the likely parent rock (protolith)?

Garnet (red) Pyroxene (green) 1

F. REFLECT & DISCUSS Which one of the rocks in this activity do you think has the highest metamorphic grade? Explain
your answer.

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