All
turloughs are found in limestone
areas. Here’s why….
Limestone
is a rock BUT
it can be dissolved (very slowly) by rainwater.
Rain travels through little cracks in the rock, dissolving as it goes and
making the cracks wider and wider. (See picture above.)
Some of these cracks or channels are large enough for a person to walk
through! So the rain just disappears right into the ground through 'swallow
holes', flows through the
channels and re-emerges later through springs.
In wintertime when a lot of rain falls and the underground water level is
high, the springs cannot cope with all the water trying to get through them and
the water appears again over the ground temporarily. Flooding appears to a depth
of about two metres although some can reach five metres. This is a turlough.