Question

Which one of the following statements correctly describes the features in the geological map? 

 

• A. Horizontal sedimentary beds above a basalt basement
• B. Anticline consisting of sedimentary rocks and basalt
• C. Syncline consisting of sedimentary rocks and basalt
• D. Steep south-dipping sedimentary beds above a basalt basement

Hint:

When interpreting geological maps, look for the shape and orientation of the layers. Horizontal beds suggest undisturbed sedimentary rocks, often lying above older rock formations like basalt.

Answer 1

The Correct Option is A

Step 1: Interpreting the Geological Map.
The map features several sedimentary units—sandstone, limestone, and shale—resting atop a basaltic basement. The sedimentary layers appear laterally continuous and undisturbed, indicating horizontal or near-horizontal bedding. There is no indication of deformation such as folding or faulting.

Step 2: Evaluating the Options.
- Option (A): Correct ✅ — The sedimentary layers are horizontally bedded above a basement of basalt. This interpretation is directly supported by the stratigraphic order and map patterns.
- Option (B): Incorrect ❌ — An anticline would exhibit folded layers with the oldest in the core, but the map shows no such structure.
- Option (C): Incorrect ❌ — A syncline implies downwarped folding with the youngest rocks in the center, which isn’t evident.
- Option (D): Incorrect ❌ — Steep dips or angular relationships are not present on the map; the strata appear flat.

Conclusion:
Option (A) is the best interpretation, indicating horizontally bedded sedimentary rocks overlying a basaltic basement.