Question

Which metamorphic rock is formed by the recrystallization of Limestone ?

• A. Slate
• B. Schist
• C. Marble
• D. Gneiss

Hint:

It's useful to remember some common parent rock $\rightarrow{}$ metamorphic rock pairs:
- Limestone $\rightarrow{}$ Marble
- Sandstone $\rightarrow{}$ Quartzite
- Shale $\rightarrow{}$ Slate $\rightarrow{}$ Phyllite $\rightarrow{}$ Schist $\rightarrow{}$ Gneiss (this shows increasing metamorphic grade)
- Granite $\rightarrow{}$ Gneiss

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks to identify the metamorphic rock that has limestone as its parent rock (protolith).

Step 2: Detailed Explanation:
Metamorphic rocks are formed when existing rocks are changed by heat, pressure, or chemical reactions.
Let's look at the parent rocks for the given options:
-

Marble: This is a non-foliated metamorphic rock composed primarily of recrystallized carbonate minerals, most commonly calcite or dolomite.
The parent rock of marble is

limestone (composed of calcite) or dolostone (composed of dolomite).
This matches the question.
-

Slate: This is a fine-grained, foliated metamorphic rock formed from the low-grade metamorphism of shale or mudstone.
-

Schist: This is a medium- to coarse-grained, foliated metamorphic rock.
It forms at a higher grade of metamorphism than slate, often from shale or mudstone as the original parent rock.
-

Gneiss: This is a high-grade, foliated metamorphic rock characterized by distinct bands of different minerals.
It can form from various parent rocks, including granite or sedimentary rocks like shale.

Step 3: Final Answer:
The metamorphic rock formed from the recrystallization of limestone is marble.
This corresponds to option (C).