Among the following rocks, the one with highest metamorphic grade is
Show Hint
- chlorite schist
- glaucophane schist
- phyllite
- gneiss
The Correct Option is D
Solution and Explanation
Metamorphic grade refers to the intensity of metamorphism that a rock has experienced, primarily determined by temperature and pressure. Low-grade rocks form under mild conditions, while high-grade rocks form under extreme heat and pressure.
Step 2: Comparing the options.
(A) Chlorite schist: Low-grade metamorphic rock.
(B) Glaucophane schist: Medium-grade, typically formed under high pressure but lower temperature (blueschist facies).
(C) Phyllite: Low-grade metamorphic rock, intermediate between slate and schist.
(D) Gneiss: High-grade metamorphic rock formed under intense metamorphism.
Step 3: Conclusion.
Gneiss has the highest metamorphic grade among the given options.
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