Choose the reaction(s) indicating metamorphism of pelites at T>600°C and P<8 kbar.
Show Hint
- albite + actinolite → hornblende + quartz
- muscovite + quartz → sillimanite + K-feldspar + H2O
- muscovite + biotite + quartz + H2O → sillimanite + melt
- albite → jadeite + quartz
The Correct Option is B, C
Solution and Explanation
- The reaction (B) and (C) are typical of metamorphic reactions occurring under high-temperature conditions (>600°C) and moderate pressure (<8 kbar) for pelitic rocks.
- Reaction (A) is a low-temperature metamorphic reaction that occurs in different conditions, while (D) does not reflect typical pelite metamorphism at these conditions.
Step 2: Conclusion.
The correct answer is (B) and (C). These are the reactions consistent with the given metamorphic conditions.
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