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Difficulty: MediumLandform Evolution by Running Water and Underground Water

In a karst landscape, percolating carbonated groundwater dissolves and expands the vertical joints of exposed limestone bedrock, creating a characteristic pavement structure of flat-topped blocks separated by deep vertical fissures. Which geomorphological term specifically identifies these deep solution fissures?

  1. GrikesAnswer
  2. B
    Clints
  3. C
    Stalagmites
  4. D
    Natural levees

Answer

Grikes are the deep vertical solution fissures formed in a limestone pavement.
Grikes is the correct term for the deep vertical channels or fissures formed when carbonated rainwater percolates into limestone joints and dissolves the surrounding rock. This creates the classic karst surface feature known as a limestone pavement.

Step-by-Step Solution

1
Analyze the landform process described in the stem
Rainwater absorbing carbon dioxide forms weak carbonic acid (H2CO3H_2CO_3), which dissolves calcium carbonate (CaCO3CaCO_3) in well-jointed limestone through carbonation.
Chemical solution along joints creates a limestone pavement consisting of two distinct alternating features: blocks and fissures.
2
Distinguish between surface solution features of a limestone pavement
The widened vertical joints/fissures are called grikes, while the raised, flat limestone slabs left standing between them are called clints.
Precise geomorphological classification requires identifying whether the feature represents the eroded trench or the remnant block.

Key Concept

Karst Surface Solution Features (Limestone Pavement)
Estimated Time:1m 0s
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Topics

Landform Evolution by Running Water and Underground Water

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