Step 1: Understanding the geological age of volcanic events.
Each of these volcanic provinces in India belongs to a specific geologic era:
- Dalma volcanics: Precambrian (Proterozoic age)
- Panjal volcanics: Permian–Triassic age
- Rajmahal volcanics: Early Cretaceous age
- Deccan volcanics: Late Cretaceous to Early Paleogene (≈66 Ma)
Step 2: Identifying the youngest event.
Among these, the Deccan volcanics represent the most recent volcanic activity, forming just before the Cretaceous–Paleogene boundary.
Step 3: Conclusion.
Hence, the Deccan volcanics are the youngest volcanic event.