Water present in the holes and cracks of underground rooks situated below the upper surface of the earth is known as underground water. In limestone regions, various topographies are formed by underground water above and below the surface due to the process of oxidation. The word ‘Karst’ has originated from the Yugoslavian word ‘Krass’, which means lime region.
The word ‘karts region’ has been taken from the Yugoslavian word ‘krass region’. On the basis of this name, topographies formed across all the limestone regions in the countries of the world are known as karst topographies. Here, various topographies are formed by erosional and depositional activities.
Following is a description of these topographies :
1. Erosional Topographies:
(a) Tera Rossa: Red and brown soils formed by oxidation are known as Tera Rossa.
(b) Lapies: These are pointed and thorny topographies which resemble lake beds.
(c) Sink – Hole: These are troughs formed by the process of oxidation of limestone by water containing carbon dioxide. Swallow holes and dolines are also the same type of troughs, but they are comparatively larger in size.
(d) Swallow – Hole: These holes are bigger in size as compared to sink holes.
(e) Doline: Holes that are bigger in size or bigger in shape are known as dolines.
(f) Uvala: These are expansive troughs formed by the mutual conjunction of various dolines.
(g) Polije: These are expansive and larger-sized troughs formed by the conjunction of many uvalas.
(h) Sinking Creek: Innumerable holes or pores on the edge of lime, from where water appears to be sinking are known as sinking creeks.
(i) Blind Valley: In lime region, the flowing river goes underground from doline and other holes due to which the valley which lies beyond that remains arid. It is known as blind valley.
These erosional topographies situated in karts regions have been depicted through the following diagrams:
2. Depositional topographies:
(a) Stalactite: This is a solid and pointed structure hanging from the ceiling of caves. It is formed from the vaporization of water leaking out of the ceiling.
(b) Stalagmite: This is a pillar – shaped structure formed on the ground of the cave. It is formed by the water dripping on the ground.
(c) Cave Pillar: This is a pillar – shaped structure formed by the conjunction of stalactite and stalagmite.
(d) Drip – Stone: This is a lime pillar which resembles a curtain. It is situated at the bottom of the cave.
(e) Nodules: Deposit of a type of mineral oil derived from rock holes is known as nodules.
All these depositional topographies have been depicted with the help of the following diagram:
