Question

Which one of the following is the correct arrangement of volcanics from the oldest to the youngest?

• A. Bijli→Rajmahal→Malani→Deccan
• B. Malani→Bijli→Deccan→Rajmahal
• C. Bijli→Malani→Rajmahal→Deccan
• D. Malani→Rajmahal→Bijli→Deccan

Hint:

Always remember the age order of Indian volcanics: Bijli (Precambrian) $<$ Malani (Proterozoic) $<$ Rajmahal (Mesozoic) $<$ Deccan (Cretaceous).

Answer 1

The Correct Option is C

Step 1: Recall the major volcanic events in the Indian subcontinent.
- The volcanic provinces of India are spread across different geological ages. - The sequence from oldest to youngest is determined based on radiometric dating and stratigraphic position. Step 2: Ages of the volcanic provinces.
- Bijli volcanics (Precambrian): These are among the oldest volcanic rocks in India, occurring in the Precambrian time.
- Malani volcanics (Late Proterozoic, $\sim$ 750 Ma): Famous for acid volcanism in Rajasthan, one of the largest felsic volcanic provinces.
- Rajmahal Traps (Jurassic–Cretaceous boundary, $\sim$ 117 Ma): Located in eastern India, associated with Gondwana rifting.
- Deccan Traps (Late Cretaceous, $\sim$ 66 Ma): One of the world’s largest continental flood basalt provinces. Step 3: Ordering from oldest to youngest.
1. Bijli volcanics (oldest)
2. Malani volcanics
3. Rajmahal volcanics
4. Deccan volcanics (youngest)
Step 4: Match with the given options.
This exact sequence matches with option (C). \[ \boxed{\text{Bijli $\rightarrow$ Malani $\rightarrow$ Rajmahal $\rightarrow$ Deccan}} \]