The Sub- Old Red Sandstone Surface in Southern Ireland

Some facts are presented concerning the nature of the sub - Old Red Sandstone surface in Ireland south of a line from Galway to Dublin. It is concluded that the surface behaves regionally as a plane, folded and faulted by Armorican movements. Exceptions to this are a "scarp" feature through the Galty Mountains, and the more lately covered Leinster massif. Otherwise irregularities are on a small, though variable, scale.