The correct option is 2 and 3 only
Explanation
The Karbi Anglong Plateau, located in Assam, is geologically a part of the ancient Peninsular Block of India. Unlike the Himalayas, which are young fold mountains, this plateau represents a detached portion of the Indian Shield.
- Statement 1 is Incorrect: The Karbi Anglong Plateau is not a young fold mountain system. Young fold mountains, such as the Himalayas, were formed by the collision of tectonic plates during the Tertiary period. In contrast, the Karbi Anglong Plateau is an eroded remnant of the ancient, stable Peninsular Block, composed of old crystalline, igneous, and metamorphic rocks.
- Statement 2 is Correct: The Karbi Anglong Plateau and the Meghalaya Plateau are separated from the main Peninsular Block (specifically the Chotanagpur Plateau) by a wide gap known as the Malda Fault (or the Rajmahal-Garo Gap). This depression was formed due to down-warping during the Himalayan orogeny and was subsequently filled by alluvial deposits from the Ganga and Brahmaputra rivers.
- Statement 3 is Correct: Geologically, the Karbi Anglong Plateau is an eastward extension of the Peninsular Block. It shares similar geological characteristics with the Chotanagpur Plateau and the Meghalaya Plateau, consisting primarily of Archean gneisses and schists.
Key Takeaway: The Karbi Anglong and Meghalaya Plateaus are geologically detached extensions of the Peninsular Block, separated from the Chotanagpur Plateau by the Malda Fault, and are distinct from the Himalayan fold mountain system.