Question:
Discuss the conditions required for the development of Karst topography with associated features. ( 63rd BPSC, 2019)
Answer:
Karst topography is distinct landforms features developed mainly by groundwater agents in the limestone or dolomite region. Karst topography developed through a process of solution and deposition of water-soluble rocks such as limestone and dolomite.
The following are conditions required for the development of Karst topography:
- The region should have the presence of large stretches of thick water-soluble rocks such as limestone.
- Rocks should be permeable, jointed, and cracked.
- Should have sufficient rainfall or sufficient source of water to dissolve the carbonate rocks.
- The absence of surface drainage and a well-developed groundwater channel is needed for the formation of karst topography and associated features.
The following are the associated features of Karst topography:
There are two types of features of Karst topography.
- Erosional features:
- Depositional features.
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| Karst Topography |
Erosional features:
Erosional features are created due to erosion on the water-soluble rocks. The following are three important erosional features of Karst topography.
Sinkhole:
- It is nearly circular in shape at the top and funnel-shaped toward the bottom is called a sinkhole. Water percolates inside the ground through sinkholes.
Sink Valley;
- Collapse sinks are created by merging or collapsing two or more sinks.
Cave:
- In areas where there are alternative arrangements of hard rocks ( shale, sandstone, quantize) and soft rocks( limestone or dolomite), caves are formed due to the dissolution of soft rocks.
Depositional features of Karst Topography:
As we know that limestone is made of calcium carbonate that is easily soluble in carbonated water( Co2+Water). The solution of calcium carbonate is deposited when the water gets evaporated.
There are mainly three types of the depositional features of karst topography:
Stalactites:
- It is crustal shaped and hangs on the roof.
Stalagmite:
- Deposit of calcium carbonate that has risen upon floors.
Pillars:
- When the deposit of calcium carbonate reaches from floor to roof in the cave and it stands like a pillar.
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