Question

______ are longitudinal valleys formed as a result of folding when Eurasian plates and Indian plates collided.
1. Ridges
2. Ranges
3. Craters
4. Duns

Answer 1

Correct Answer - Option 4 : Duns

The correct answer is Duns.

 

• Duns are longitudinal valleys formed as a result of folding when Eurasian plates and Indian plates collided.
  • Longitudinal valleys are the longitudinal valleys between the lesser Himalayas and Shivalik are known as 'duns' in the west and 'duars' in the east.
  • Dun is a local word for valley, particularly an open valley in the Sivaliks or between the Sivaliks and higher Himalayan foothills.
  • Other valleys in this region have names like Patli Dun, Kotli Dun, Pinjore Dun in Himachal.
  • Unlike typical river valleys, duns have a structural origin and are covered with boulders and gravel originating from the erosion of the Himalayas and the Shiwalik uplands.

• A longitudinal valley is an elongated valley found between two almost parallel mountain chains in geologically young fold mountains, such as the Alps, Carpathians, Andes, or the highlands of Central Asia.
• They are often occupied and shaped by a subsequent stream.
• Duns are longitudinal valleys created when the Eurasian plate and the Indian plate collided as a result of folding.
• Among lesser Himalayas and Shivalik, they are formed.
  • The valleys are accumulated with coarse alluvium passed down by Himalayan rivers.