sea approximately 350 million years ago, and compressed
into horizontal strata with fossil
corals,
crinoids,
sea urchins
and
ammonites.
Glaciation following the
Namurian
phase facilitated greater denudation.
The result is that Inishmore and the other islands are among the finest
examples of Glacio-Karst
landscape
in the world. The effects of the
last
glacial period
(the Midlandian)
are most in evidence, with the island overrun by ice during this glaciation.
The impact of earlier
Karstification
(solutional erosion) has been
eliminated by the
last glacial
period. So any Karstification now seen dates from approximately 10,000 years
ago and the island Karst is thus recent.
Solutional processes have widened and
deepened the grykes of the limestone pavement. Pre-existing lines of weakness
in the rock (vertical joints) contribute to the formation of extensive fissures
separated by clints (flat pavement like slabs). The rock karstification
facilitates the formation of sub-terrainean drainage.
