Question 8: Describe how the Himalayas were formed.
Answer: The Indian Peninsula drifted towards the north and finally collided with the much larger Eurasian Plate. As a result of this collision, the sedimentary rocks which were accumulated in the geosynclines (known as Tethys) got folded and formed the mountain systems of the West Asia and Himalaya.
Question 9: Which are the major physiographical divisions of India? Contrast the relief of the Himalayan region with that of the Northern Plains of India.
Answer: The landmass of India can be divided into following major physiographic divisions:
The Himalayan Mountains
The Northern Plains
The Peninsular Plateau
The Indian Desert
The Coastal Plains
The Himalayan region is rugged and shows great variations in terms altitude. The Northern Plains, on the other hand, is more or less level and has least variations in terms of altitude. The Himalayan region is formed by rocks and unconsolidated sediments. The Northern Plains is composed of alluvial deposits.
Question 10: Write short notes on the following:
The Indian Desert
Answer: The Indian desert lies towards the western margins of the Aravali Hills. This region gets scanty rainfall which is less than 150 mm in a year. Hence they climate is arid and vegetation is scanty. Luni is the only large river but some streams appear during rainy season. Crescent-shaped dunes (barchans) abound in this area.
The Central Highlands
Answer: The Central Highlands lies to the north of the Narmada river. It covers the major portion of the Malwa plateau. The rivers in this region flow from southwest to northeast; which indicates the slope of this region. It is wider in the west and narrower in the east. Bundelkhand and Baghelkhand mark the eastward extension of this plateau. The plateau further extends eastwards into the Chhotanagpur plateau.
The Island groups of India
Answer: The Lakshadweep Islands are in the Arabian Sea. Its area is 32 sq km. The administrative headquarters of Lakshadweep is at Kavaratti island. This group of islands is rich in terms of biodiversity.
The Andaman and Nicobar Islands are bigger in size and has more number of islands. This group of islands can be divided into two groups. The Andaman is in the north and the Nicobar is in the south. These islands too have rich biodiversity.