Question

Match the stratigraphic Formations in Group I with the corresponding Geologic Periods in Group II.

Group-I	Group-II
P. Kopili Shale	1. Permian
Q. Raniganj Formation	2. Eocene
R. Quilon Formation	3. Cretaceous
S. Dalmiapuram Formation	4. Miocene

• A. P-3; Q-1; R-2; S-4
• B. P-2; Q-1; R-4; S-3
• C. P-4; Q-1; R-3; S-2
• D. P-1; Q-3; R-2; S-4

Hint:

Recall the basin and depositional setting of each named formation, then attach the period that basin's sequence belongs to.

Answer 1

The Correct Option is B

Step 1: Recall what each formation is and where it sits in the stratigraphic column.
This question checks whether you know the age assigned to four well known Indian rock units. Each one belongs to a different sedimentary basin and a different period, so we match them one at a time.

Step 2: Place the Kopili Shale (P).
The Kopili Formation crops out in Assam and Meghalaya in the Assam Shelf basin. It is dated as late Eocene in age, deposited in a shallow marine setting. So P matches Eocene (2).

Step 3: Place the Raniganj Formation (Q).
The Raniganj Formation is the uppermost coal bearing unit of the Damuda Group in the Raniganj Coalfield, part of the Gondwana sequence of peninsular India. Gondwana coal measures of this kind are Permian in age. So Q matches Permian (1).

Step 4: Place the Quilon Formation (R).
The Quilon Formation occurs in the Kerala Konkan basin along the west coast. It is a limestone rich unit well known for its planktonic foraminifera, and it is dated as early Miocene. So R matches Miocene (4).

Step 5: Place the Dalmiapuram Formation (S).
The Dalmiapuram Formation belongs to the Uttatur Group of the Cauvery Basin in Tamil Nadu. This group is Cretaceous in age, and Dalmiapuram in particular is placed in the early Cretaceous to Cenomanian interval. So S matches Cretaceous (3).

Step 6: Put the pairs together and check the options.
We now have P-2, Q-1, R-4, S-3.

(A) P-3; Q-1; R-2; S-4: Wrong, because it puts Kopili Shale in the Cretaceous and Quilon Formation in the Eocene, both incorrect.

(B) P-2; Q-1; R-4; S-3: Matches our derivation exactly. Correct.

(C) P-4; Q-1; R-3; S-2: Wrong, because it places Kopili Shale in the Miocene and Quilon Formation in the Cretaceous.

(D) P-1; Q-3; R-2; S-4: Wrong, because it swaps the ages of Kopili Shale and Raniganj Formation and misplaces Quilon and Dalmiapuram too.

Step 7: Final conclusion.
\[ \boxed{P\text{-}2;\ Q\text{-}1;\ R\text{-}4;\ S\text{-}3} \]
Hence, the correct option is (B).