Question.
Discuss the basis of various explanations for the formation of Shiwalik.
( UPSC Geography Optional Paper 2 2024, 10 Marks)
Answer.
About Shiwalik Himalayas:
The literal meaning of Shiwalik is "long hairs of Shiva".
The outermost [ southernmost] range of the Himalayas is known as Shiwalik or outer Himalayas.
Shiwalik's range is spread in Pakistan, India, Nepal, and Bhutan.
Average Width: 10 to 50 km
Average elevation: 3000 to 4000 feet ( 900 to 1100 meters)
Approx Length: 2400 km
Time of Shiwalik Formation:
Shiwalik range was formed after the formation of the Greater Himalayas and Middle Himalayas. It was developed around 2 to 20 million years ago ( Tertiary period).
Various explanations [ Theory] for the formation of Shiwalik:
There are two theories [i.e. Kober's geosyncline theory and plate tectonic theory] that explain the formation of Shiwalik.
As we know Himalayan mountain ranges formed on the Tethys Sea( geosyncline region) due to the northern movement of the Indian plate. Shiwalik range formed after the formation of the Greater Himalayas range and the Lesser Himalayas range.
We will understand the Shiwalik formation with the help of the above two theories combined.
The following three stages are in the formation of Shiwalik:
Stage -1:
Himalayan rivers brought sediments[ Alluvial deposits, rocks, sands, and boulders] from the greater Himalayas and Middle Himalayas and they were deposited in the southern part of the Lesser [ middle] Himalayan range.
Stage-2:
Over time, these sediments created temporary lakes [ geosyncline region], and rivers continuously deposited their sediments in the temporary lakes.
Stage-3:
Due to the northern movement of the Indian plate, sediment deposited in the temporary lakes was compressed, folded, and hardened, which resulted in the formation of the Shiwalik range.
You may also like:
ConversionConversion EmoticonEmoticon