Question

Consider the following statements and identify the right ones :-
1. The peninsular block is rigid and stable in its geological structure.
2. The Himalayas are young, weak and flexible in its geological structure.
(a) Only 1
(b) Only 2
(c) Both 1 and 2
(d) None of these

Answer 1

Hint : Tectonic in origin, these mountains are dissected by fast-flowing rivers that are in their youthful period. Various landforms are representative of this stage, such as gorges, V-shaped valleys, rapids, waterfalls, etc.

Complete answer:
An irregular line running from Kachchh along the western flank of the Aravali Range near Delhi and then approximately parallel to the Yamuna and the Ganga as far as the Rajmahal Hills and the Ganga Delta can be taken from the northern boundary of the Peninsular Block. Apart from these, extensions of this block are also the Karbi Anglong and the Meghalaya Plateau in the northeast and Rajasthan in the west. In fact, the Peninsula is surrounded by a large complex of very ancient gneisses and granites, which is a huge component of it. The Peninsula has stood as a rigid block since the Cambrian era, except for some of its western coast, which is buried under the sea, and some other parts have shifted due to tectonic action without impacting the initial basement. In comparison to the rigid and stable Peninsular Block, the Himalayas and the other Peninsular mountains are young, fragile and dynamic in their geological structure. They are still also subject to the interplay of exogenous and endogenous forces, contributing to the creation of faults, folds and plains of thrust. Tectonic in origin, these mountains are dissected by fast-flowing rivers that are in their youthful period.

Correct option is (c) Both 1 and 2 .

Note : In comparison to the rigid and stable Peninsular Block, the Himalayas and the other Peninsular mountains are young, frail and fluid in their geological structure. They are still also subject to the interplay of exogenous and endogenous forces, contributing to the creation of faults, folds and plains of thrust.