Step 1: Understanding the depositional environments of conglomerates.
Conglomerates are coarse-grained sedimentary rocks composed of rounded pebbles and boulders. These rocks are typically deposited in high-energy environments, such as alluvial fans, where fast-moving water transports and deposits large clasts.
Step 2: Analyzing the options.
(A) aeolian dunes: Aeolian dunes are formed by wind, and they typically deposit fine-grained sand, not conglomerates.
(B) tidal flats: Tidal flats are low-energy environments where fine sediments like mud and silt are deposited, not conglomerates.
(C) alluvial fans: This is the correct answer. Alluvial fans are high-energy depositional environments where conglomerates are commonly formed.
(D) river flood plains: While river flood plains can deposit coarse sediments, conglomerates are more commonly associated with alluvial fans.
Step 3: Conclusion.
The correct answer is (C) alluvial fans because these environments are typically where conglomerates are deposited.
In a sedimentary succession shown in the figure, the last occurrence of the fossil species Q (dated 50 Ma) and the first occurrence of the fossil species R (dated 30 Ma) are recorded at Y and X, respectively. The estimated rate of sedimentation is (assume constant rate of sedimentation). 
Match the primary sedimentary structure in Group I with the corresponding process of formation in Group II.
\[\begin{array}{|l|l|} \hline \textbf{Group I} & \textbf{Group II} \\ \hline \text{P. Asymmetric ripples} & \text{1. Water escape} \\ \hline \text{Q. Dish and pillar} & \text{2. Bed load transportation of sediments} \\ \hline \text{R. Flute cast} & \text{3. Deposition from alternate traction and suspension load} \\ \hline \text{S. Wavy bedding} & \text{4. Scouring by turbulent eddy} \\ \hline \end{array}\]