1. Deep gorges
2. U-turn river courses
3. Parallel mountain ranges
4. Steep gradients causing landsliding
Which of the above can be said to be the evidence for Himalayas being young fold mountains?
(a) 1 and 2 only
(b) 1, 2 and 4 only
(c) 3 and 4 only
(d) 1, 2, 3 and 4
11. Answer: (d)
There are three types of mountains- Fold Mountains, Block Mountains, and the Volcanic Mountains. The Himalayan Mountains and the Alps are young fold mountains with rugged relief and high conical peaks.
Statement 1 is correct: A gorge is a narrow valley with steep, rocky walls located between hills or mountains. The Himalayas being young fold mountains are known for deep georges. Statement 2 is correct: The main Himalayan River systems are the Ganga, the Indus and the Brahmaputra River systems. The Himalayan rivers form large basins. The Brahmaputra originates in the Man Sarovar lake, also the source of the Indus and the Satluj. It is slightly longer than the Indus, but most of its course lies outside India. It flows eastward, parallel to the Himalayas. Reaching Namcha Barwa (7757 m), it takes a U-turn around it and enters India in Arunachal Pradesh known as dihang. The undercutting done by this river is of the order of 5500 metres. In India, it flows through Arunachal Pradesh and Assam, and is joined by several tributaries.
Statement 3 is correct: The Himalayas are a series of parallel mountain ranges extending along the North-West to the South-East direction (known as the Strike of the Himalayas). These ranges are separated by longitudinal valleys. They include,
O Trans-Himalayas
O The Greater Himalayas or Himadri
O The Lesser Himalayas or Himachal
O Shiwaliks or the Outer Himalayas
O The Eastern Hills of Purvanchal
Statement 4 is correct: Himalayan mountains have a high altitude, steep gradients, snow capped mountains, youthful river drainage systems, and dissected topography. The southern slope of the Himalayas is very steep compared to its northern slope forming a hog back shape. The steep gradient renders the region prone to landslides
