Question

Which of the following statements is/are NOT correct for stratigraphy of the Himalaya?

• A. Tethyan Sedimentary Sequence rocks are of Precambrian age
• B. The Lesser Himalayan Sequence rocks are younger than the Higher Himalayan Crystallines
• C. The Sub-Himalayan Sequence rocks are younger than the Lesser Himalayan rocks
• D. Collisional Himalayan orogeny occurred in the Cenozoic Era

Hint:

Understanding the geologic history of the Himalayas helps clarify the stratigraphic sequence and age relationships of various rock units.

Answer 1

The Correct Option is A, B

Step 1: Evaluating the geological sequences of the Himalayas.
To answer the question correctly, we need to verify the age and relative positions of the different Himalayan rock sequences:

- Tethyan Sedimentary Sequence: These rocks were deposited in the Tethys Ocean and are primarily Mesozoic to Cenozoic in age — not Precambrian. Hence, Option (A) is incorrect.
- Lesser Himalayan Sequence: These rocks are largely Precambrian to Paleozoic in age. The Higher Himalayan Crystallines are metamorphosed and represent the deeper, older crustal levels but were exhumed more recently. However, in terms of stratigraphic age, the Lesser Himalayan rocks are older. Thus, Option (B) is incorrect.
- Sub-Himalayan Sequence: These are the youngest sediments, mostly Cenozoic molasse deposits, and lie to the south of the Lesser Himalaya. Hence, Option (C) is correct.
- Collisional Himalayan Orogeny: This refers to the tectonic event caused by the collision of the Indian and Eurasian plates and occurred during the Cenozoic Era. Therefore, Option (D) is correct.

Step 2: Conclusion
✅ Correct Statements: (C) and (D)
❌ Incorrect Statements: (A) and (B)