Question

Which one of the following primary sedimentary structures is NOT used for palaeocurrent analysis?

• A. Current crescent
• B. Flute marks
• C. Symmetrical wave ripples
• D. Imbrication of pebbles

Hint:

When studying sedimentary structures, remember that symmetrical ripples are a sign of oscillatory wave motion, not directional currents.

Answer 1

The Correct Option is C

Step 1: Understanding the question.
The question asks which sedimentary structure is not used for palaeocurrent analysis. Palaeocurrent analysis involves determining the direction of past water flow based on sedimentary features.
Step 2: Analyzing the options.
(A) Current crescent: This is used to determine the direction of current flow.
(B) Flute marks: Flute marks are formed by currents and are used for palaeocurrent analysis.
(C) Symmetrical wave ripples: Correct — Symmetrical wave ripples indicate wave motion, not unidirectional current flow, and are not used for palaeocurrent analysis.
(D) Imbrication of pebbles: This structure is also used to infer palaeocurrent direction.
Step 3: Conclusion.
The correct answer is (C) Symmetrical wave ripples, as they are not used for palaeocurrent analysis.