Mining in Offaly
Until recently there were no recorded mines in Offaly. However following the collapse of a mine shaft in Blundell Hill, Edenderry in September 2011, Dr Martin Critchley and Dr Sharon Schwartz have carried out research into this mine which was seeking lead and silver deposits. Download Blundell Hill Report 2011.
Field Trips
Each year as part of the Offaly Naturalist's Field Club programme there is a geology weekend in late summer led by John Feehan. There is an introductory talk on the Friday night and field trips on the Saturday and Sunday.
Forthcoming Publication
John Feehan is compiling a book on the geology of Laois and Offaly which will be published by Laois and Offaly County Councils in 2011/ 2012. If you would like to receive notification about this publication please email the Offaly Heritage Office.
Wavestone / Mushroom Stones
After the last Ice Age, the water table was considerably higher than it is today. Wavestone/ Mushroom stone is the name given to a limestone rock which has wave marks on it which indicate this water level. Some are shaped like mushrooms, others have an overhang facing in just one direction but all are notched and undercut in such a fashion as to suggest prolonged exposure to standing water at some time in the past. These help us to decipher where the ancient shore lines were.
To find out more about these unusual features of the Offaly landscape see the mushroom stone website or download the publication Ireland's Mushroom Stones, Relics of a Vanished Lakeland Louise Dunne and John Feehan. 2003. This can be downloaded - due to the size of it, it is in three parts part 1(6MB), part 2 (8MB), part 3 (6MB)
If you know of a location of a wavestone or mushroom stone in your area please check is it in the 2003 publication and if not please email the heritage office. John Feehan and Louise Dunne are updating this publication to incorporate the new finds and information since 2003.
The mushroom stone at Endrim.
Eskers
The last ice age was around 15,000 years ago. Rivers flowed under the ice as the ice began to retreat. These rivers built up layers of sand and gravel that now form ridges in the landscape called eskers. They are particularly evident in the midlands and in Offaly.
The Offaly Heritage Foum commissioned a Study of Eskers west of Tullamore in 2006.