ZIMSEC O Level Geography Notes: Limestone pavements
- Limestone pavements are flat areas of exposed limestone rocks.
- They are part of the dissolved bedding plate which may have been exposed because the surface soil may have been removed by glacial activity and never replaced.
- Where the pavement has joints that reach the surface, these joints may be widened by acid rain water.
- This process is called carbonation.
- The widening of the joints leaves deep incisions/gashes/fissures called grikes.
- Some grikes such as found in the Limestone regions of England can be about half a meter wide.
- Separating the grikes are flat-topped yet dissected blocks referred to as clints.
- As time passes these clints are levelled by denudation processes including the widening of the grikes until a lower bedding plane is exposed.
- This bedding plane’s joints are in turn attacked by weathering in the form of carbonation forming grikes and thus repeating the process all over again.
- Grikes can also be formed by subsurface weathering in much the same way as tors are formed.
- Acidic water may seep into the ground into joints in the underlying limestone bedding rock.
- Over time it widens these joints and when the overlying soil is washed away by erosion the clints and grikes are exposed.
A diagram showing clints and grikes.
Grikes are sometimes known as grykes.
To access more topics go to the Geography Notes page.
Quick NetOne, Telecel, Africom, And Econet Airtime Recharge
If anything goes wrong, click here to enter your query.