Limestone Pavement : Grikes

A remarkable feature of the Burren is the large expanse of bare limestone, called limestone pavement, which predominates in the north and west of the area. This is a result of glaciation which scoured the rock clean of any superficial cover that formerly may have lain on the surface, thus exposing and smoothly polishing the underlying bedrock.

Pavements are made up of two separate but integral parts known as clints and grykes. Clints are the blocks of limestone that constitute the paving, their area and shape is directly dependent upon the frequency and pattern of grykes. Grykes, or scailps, are the fissures that isolate the individual clints.

The most dominant gryke system runs almost north to south and there is a secondary less-developed system at right angles to this. Grykes can stretch for hundreds of feet until they suddenly terminate or are lost beneath superficial deposits.

Grykes are usually straight but are occasionally curvilinear. In places, water draining from the horizontal top cuts deep channels or runnels into the shoulders of the clint, thus directing the water into the gryke where it will eventually widen the gryke and undermine the clint itself. In areas of flat pavement, most plants live within the grykes where the crevices provide moist shelter. Ferns in particular thrive here, as well as perennial herbs such as bloody crane's-bill and herb robert.

Dwarf examples of shrubs usually associated with woodlands like blackthorn, holly and honeysuckle are also found here.


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