A Guide to Cork City's Geological Heritage

Locations of diamicts - the graffiti comes in handy here when spotting them.

Karst features are also very visible here. As the limestone has been dissolved by weakly acidic waters running through it, large crevasses and even caves formed here. Small-scale examples of these can be seen along the cliff, in particular along the eastern section. Related to these karsts, remember how we talked about Quaternary ice sheets? We can see some leftovers from these here. At the eastern sections of the cliff, within the karsted crevasses, you will find a sludge of pebbles and sediments. These infills are called ‘diamicts’, and they occurred as the ice sheets deposited sediments into the dissolved crevasses of the limestone. These sediment fillings in the limestone cause plenty of problems for residents in Ballinlough and Ballintemple. Houses have been sinking slowly into the ground, and some properties are tilting severely and have required extensive renovation and reinforcement work.

Geotechnical reports have shown that a lot of this instability is caused by infrastructure resting on unstable limestone rock layers or resting on glacial sediments which are caving and compressing into the limestone layers. The diamicts to the left show small-scale examples of this phenomenon. These geotechnical reports can luckily help us better understand where these phenomenon takes place for future planning

A closer look at a limestone-hosted diamict.

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