The original non-metamorphic rock that undergoes profound physical or chemical changes leading to the formation of a metamorphic rock is known as:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Protolith.
A protolith is the original, non-metamorphic rock that undergoes metamorphism—intense heat, pressure, or chemically active fluids—to form a metamorphic rock. The mineral composition and texture of the protolith influence the type of metamorphic rock produced.
Other options:
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Laterite: A highly weathered soil rich in iron and aluminum, formed in tropical regions; not a precursor to metamorphic rocks.
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Bedrock: The solid rock underlying soil or regolith; while it may become a protolith, the term itself does not specify metamorphic potential.
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Regolith: A layer of loose, fragmented material above bedrock, including soil, sand, and gravel; not a direct precursor to metamorphic rocks.