Question
Which of the following geographical features or phenomena is/are associated with the Peninsular Block of India?
1. Submergence of parts of the western coast due to tectonic activity
2. Presence of residual mountain ranges such as the Veliconda hills and Mahendragiri hills
3. Deep, V-shaped river valleys formed by fast-flowing rivers
Explanation
The Peninsular Block is one of India’s oldest and most stable geological formations. Its present relief and drainage pattern reflect long-term erosion as well as major tectonic changes along its western margin.
Statement 1 — Correct: During the Early Tertiary period, the western margin of the Peninsular Block underwent tectonic subsidence, leading to partial submergence and contributing to the formation of the present western coastal configuration. This also disturbed the earlier symmetrical drainage pattern.
Statement 2 — Correct: The Peninsular Block is an ancient, rigid and stable landmass, dominated by highly denuded residual and relict mountains. Ranges such as the Aravalli, Nallamala, Javadi, Velikonda, Palkonda and Mahendragiri are examples of these old residual hills.
Statement 3 — Incorrect: Peninsular rivers are generally mature rivers, as the drainage system is much older than the Himalayan system. They typically have broad, shallow and graded valleys with gentle gradients. In contrast, deep gorges, V-shaped valleys, rapids and waterfalls indicate stronger vertical erosion and are more characteristic of the younger Himalayan drainage system.