Question

Match the type of rock with its metamorphic form.

Igneous/Sedimentary rock	Metamorphic rock
(P) Shale	(1) Gneiss
(Q) Limestone	(2) Quartzite
(R) Granite	(3) Marble
(S) Sandstone	(4) Slate

• A. P \(\rightarrow\) 4, Q \(\rightarrow\) 3, R \(\rightarrow\) 1, S \(\rightarrow\) 2
• B. P \(\rightarrow\) 3, Q \(\rightarrow\) 1, R \(\rightarrow\) 4, S \(\rightarrow\) 2
• C. P \(\rightarrow\) 4, Q \(\rightarrow\) 3, R \(\rightarrow\) 2, S \(\rightarrow\) 1
• D. P \(\rightarrow\) 3, Q \(\rightarrow\) 4, R \(\rightarrow\) 2, S \(\rightarrow\) 1

Hint:

Think about what each parent rock turns into under contact or regional metamorphism.

Answer 1

The Correct Option is A

Step 1: Understanding the Question.
The question gives four parent rocks, shale, limestone, granite and sandstone, and asks which metamorphic rock each one turns into under heat and pressure.

Step 2: Key Concept.
Metamorphism changes a rock's texture and mineral makeup without melting it. Each parent rock has a well known metamorphic product.
Shale (a fine grained, clay rich sedimentary rock) turns into slate at low grade, and into phyllite, schist or gneiss as the grade rises.
Limestone (mostly calcite) recrystallises into marble.
Quartz rich sandstone recrystallises into quartzite.
Granite (an igneous rock rich in quartz, feldspar and mica) develops banding of light and dark minerals under strong regional metamorphism and becomes gneiss.

Step 3: Match each pair.
(P) Shale \(\rightarrow\) Slate, which is (4).
(Q) Limestone \(\rightarrow\) Marble, which is (3).
(R) Granite \(\rightarrow\) Gneiss, which is (1).
(S) Sandstone \(\rightarrow\) Quartzite, which is (2).
Option (B) swaps shale's and limestone's products. Options (C) and (D) both send granite to quartzite and sandstone to gneiss, which is backwards, granite has no quartz sand texture to turn into quartzite, and sandstone does not build the coarse banding that defines gneiss.

Step 4: Final Answer.
P \(\rightarrow\) 4, Q \(\rightarrow\) 3, R \(\rightarrow\) 1, S \(\rightarrow\) 2, which is option (A).