Match the primary sedimentary structure in Group I with the corresponding process of formation in Group II.
\[\begin{array}{|l|l|} \hline \textbf{Group I} & \textbf{Group II} \\ \hline \text{P. Asymmetric ripples} & \text{1. Water escape} \\ \hline \text{Q. Dish and pillar} & \text{2. Bed load transportation of sediments} \\ \hline \text{R. Flute cast} & \text{3. Deposition from alternate traction and suspension load} \\ \hline \text{S. Wavy bedding} & \text{4. Scouring by turbulent eddy} \\ \hline \end{array}\]
Match the primary sedimentary structure in Group I with the corresponding process of formation in Group II.
\[\begin{array}{|l|l|} \hline \textbf{Group I} & \textbf{Group II} \\ \hline \text{P. Asymmetric ripples} & \text{1. Water escape} \\ \hline \text{Q. Dish and pillar} & \text{2. Bed load transportation of sediments} \\ \hline \text{R. Flute cast} & \text{3. Deposition from alternate traction and suspension load} \\ \hline \text{S. Wavy bedding} & \text{4. Scouring by turbulent eddy} \\ \hline \end{array}\]
Show Hint
- P-1, Q-2, R-3, S-4
- P-2, Q-3, R-1, S-4
- P-1, Q-4, R-3, S-2
- P-2, Q-4, R-1, S-3
The Correct Option is B
Solution and Explanation
Step 1: Analysis of each structure:
P. Asymmetric ripples: Formed by Bed load transportation of sediments (2)
- Asymmetric (current) ripples form when sediment grains move along the bed by traction and saltation under unidirectional current
- The asymmetry indicates flow direction
Q. Dish and pillar structures: Formed by Water escape (1)
- These are soft-sediment deformation structures created when pore water escapes upward through rapidly deposited sediments
- Dish structures are concave-up laminae, pillars are vertical escape conduits
R. Flute cast: Formed by Scouring by turbulent eddy (4)
- Flute casts are preserved scour marks on the base of beds
- Created by turbulent eddies eroding the underlying sediment
- The bulbous end points upstream
S. Wavy bedding: Formed by Deposition from alternate traction and suspension load (3)
- Wavy bedding forms when alternating conditions favor both traction (ripples/laminae) and suspension deposition (mud drapes)
- Characteristic of environments with fluctuating current velocities
Step 2: Matching:
- P → 2 (Asymmetric ripples → Bed load transportation)
- Q → 1 (Dish and pillar → Water escape)
- R → 4 (Flute cast → Scouring by turbulent eddy)
- S → 3 (Wavy bedding → Alternate traction and suspension)
Answer: (B) P-2, Q-1, R-4, S-3
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