(a) Explain the term karsi topography (b) Name any four features found in karst regions (c) Highlight five characteristics of karst regions

Answer Details

(a) Meaning of karst topography

Karst topography is the distinctive scenery that develops in regions of thick, well-jointed limestone (or other soluble rock such as dolomite or chalk) as a result of solution (carbonation) weathering. Rainwater, being a weak carbonic acid, dissolves the limestone along its joints and cracks, producing a landscape of underground drainage with characteristic surface and underground features. The name comes from the Karst region of the former Yugoslavia.

(b) Four features found in karst regions

• Swallow holes (sink holes / dolines).
• Limestone caves and caverns.
• Stalactites and stalagmites (in the caves).
• Limestone pavements with clints and grikes; also gorges and underground streams.

(c) Five characteristics of karst regions

• Underground drainage: surface streams disappear down swallow holes and flow underground, so the surface is often dry.
• Presence of caves and caverns formed by solution beneath the surface, decorated with stalactites (hanging from the roof) and stalagmites (rising from the floor).
• Bare, rocky surface with limestone pavements (clints separated by grikes) and thin, poor soils, so vegetation is scanty.
• Numerous joints and cracks in the well-bedded limestone along which solution takes place; enlarged joints and dolines are common.
• Deep gorges and steep-sided valleys formed where cave roofs collapse, and re-emergence of streams as springs at the foot of the limestone.