Question

Figures X and Y show profile sections of folds traced by two cross-bedded sandstone beds. Which one of the following is the correct interpretation? 

• A. X- Antiformal anticline; Y- Antiformal syncline
• B. X- Antiformal anticline; Y- Synformal syncline
• C. X- Overturned antiform; Y- Overturned synform
• D. X- Antiformal syncline; Y- Synformal anticline

Hint:

Anticlines and synclines are defined by the relative position of older and younger beds. Anticlines have older beds at the center, while synclines have younger beds at the center.

Answer 1

The Correct Option is D

Step 1: Understanding the Folds.
- Anticlines are folds where the older beds are in the center, and synclines are folds where the younger beds are in the center.
- The "X" figure shows an anticline with beds that dip away from the center, so it is an antiformal anticline.
- The "Y" figure shows a syncline with beds that dip towards the center, so it is an antiformal syncline.
Step 2: Analyzing the options.
(A) X- Antiformal anticline; Y- Antiformal syncline: Correct — This matches the observed fold types for figures X and Y.
(B) X- Antiformal anticline; Y- Synformal syncline: Incorrect — "Synformal" is not the correct term here.
(C) X- Overturned antiform; Y- Overturned synform: Incorrect — Both folds are not overturned.
(D) X- Antiformal syncline; Y- Synformal anticline: Incorrect — The fold types for both figures are reversed in this option.
Step 3: Conclusion.
The correct answer is (A) X- Antiformal anticline; Y- Antiformal syncline, as it accurately represents the fold types in the figures.