Landforms and their Evolution Short and Long Important Question Class 11 Geography Chapter-6 Book-Fundamental of Physical Geography

 

Question – What is the difference between a gorge and a canyon?

Answer -

• Gorge is a deep narrow valley with steep slopes on both sides, while the sides of canyon are also steep and are as deep as gorge

• The width of the canyon is almost the same at the bottom and the top, and the width of the gorge is less at the bottom and more at the top. 

• Canyons are often formed by horizontal stratification of sedimentary rocks, while gorges are formed in harder rock areas. 

Question -  Describe the eroded landforms created by glaciers?

Answer -

• The ice mass flowing on the earth in the form of a layer or as a linear flow from mountain slopes into valleys is called a glacier.

• Glaciers can flow anywhere from a few centimetres or less to a few metres per day. 

• Glaciers move mainly due to gravity.

1. The Cirque

• In the upper part of the glacier, erosion takes place on the bed, which forms troughs with steep sides, which are called cirques. 

2. Horn

• When two circles meet each other in opposite directions, a pointed peak-like shape is formed, which is called a horn.  

3. Glacial valleys/troughs

• They are U shaped.

• The bottom is broad and the edges are smooth.

• The slope is steep.

• Debris is scattered in the valley.

• Lakes emerge on rocky surfaces 

Question:  What are the eroded landforms created by ocean waves?

Answer - 

eroded landforms created by ocean waves

1. Bhrigu (cliff) 

• These are found on the seashores in the form of high, steep rocks, which are formed by the friction of waves. 

• The bottom of a sea cliff is a flat or gently sloping platform covered with debris brought by the waves.

2. Terraces

• When these platforms rise above the average height of the waves, they are called wave-eroded altars.

3. Caves

• The constant friction of the waves creates spaces at the base of the cliffs, leading to the formation of sea caves.

4. Stack

• The retreat of a cliff leaves some remnant rocks, which were formerly part of the cliff, isolated on the shore, these are called sea stacks. 

• These too are gradually destroyed by the process of erosion.

Question - Groundwater as an erosion agent creates many landforms through chemical process." Justify the statement.

Answer -

Lime-rich rocks form many landforms through chemical action in humid areas where there is heavy rainfall-

1. Solution pores

• These are funnel-shaped depressions which are circular at the top. 

• Their depth varies from half a metre to 30 metres or even more.

2. Merging pores

• These are connected to the bottom of the solution system at some depth. 

• They are formed by the dissolution process at the bottom of limestone rocks. 

3. Yuvala

• These are funnel-shaped depressions which are circular at the top. 

• Their depth varies from half a metre to 30 metres or even more.

4. Lapis 

• Gradually most of the calcareous rocks turn into troughs and trenches, leaving highly irregular, thin, and sharp ridges, called lapis, all over the area.