Karst Landscapes and Carbonation

Karst Landscape

• Terrain with landforms from chemical weathering and erosion of soluble rocks (limestone, dolomite, gypsum).
• Limestone (calcium carbonate) is vulnerable to carbonation.

Carbonation

• Rainwater absorbs $CO_2$ from air/soil, forming weak carbonic acid.
• Acid reacts with limestone ($CaCO_3$) to form calcium bicarbonate, which dissolves and is carried away.
• Gradually dissolves limestone, enlarging joints and bedding planes.

Surface Karst Features

• Limestone Pavements:
  • Exposed limestone bedrock with widened joints.
  • Clints: flat slabs of rock.
  • Grikes: deep, narrow fissures.
  • Karrens: shallow hollows on clints.
  • Fluting: grooves from acidic water runoff.
• Swallow Holes:
  • Rivers sink underground when reaching limestone.
  • Dissolve rock along cracks and bedding planes.
  • Rivers of resurgence: rivers that resurface.
  • Dry valley: downstream of the swallow hole.

Other Karst Features

• Dolines (sinkholes): rock collapses into underlying voids.
• Turloughs: seasonal lakes from underground passages filling with water.