The correct option is The Malda Fault.
Explanation
The Peninsular Block of India extends beyond the central landmass. The northeastern extension, comprising the Meghalaya Plateau and Karbi Anglong Plateau, is geologically part of the Peninsular Block but is physically separated from it by a significant geological fault.
Detailed Analysis:
- The Malda Fault (Correct): During the northward movement of the Indian Plate, a significant faulting event occurred between the Rajmahal Hills (part of the Chotanagpur Plateau) and the Meghalaya Plateau. This created a depression known as the Malda Fault (also referred to as the Garo-Rajmahal Gap). This depression was subsequently filled by alluvial deposition from the Ganga and Brahmaputra river systems, separating the northeastern plateaus from the main Peninsular Block.
- The Great Boundary Fault (Incorrect): This fault is located in Rajasthan and separates the Aravalli Range from the Vindhyan Mountains. It does not relate to the separation of the northeastern plateaus.
- The Son-Narmada Lineament (Incorrect): This is a major east-west trending tectonic zone in central India that defines the flow of the Narmada and Son rivers, separating the Vindhyan and Satpura ranges.
- The Himalayan Frontal Thrust (Incorrect): This is a thrust fault that marks the boundary between the Outer Himalayas (Siwaliks) and the Indo-Gangetic Plain to the south.
Key Takeaway:
The Malda Fault (Garo-Rajmahal Gap) is the geological feature that separates the Meghalaya and Karbi Anglong plateaus from the Chotanagpur Plateau of the main Peninsular Block.