County Dublin, Ireland

The occurrence of marine shells in the Glacial deposits of Co. Wicklow was for a long time naturally regarded as evidence of submergence beneath the sea. The striations, however, that are found on the rock-floor show that ice sheets traversed the whole country, and the uplift of materials from lower to higher layers of moving ice may now be regarded as well established. Much of our knowledge of tin-history of East Leinster in Glacial times is due to the pioneer-observer Maxwell H. Close, whose work in the Dublin district has been completed by G. W. Lamplugh. The latter geologist also showed how such immature ravines as the Scalp south of Dublin, which is cut across a granite spur, and the Glen of the Downs in Co. Wicklow already recognised by Close as post-glacial are due to torrential waters set free by the melting of the ice-fronts. The gravels accumulated in subglacial channels form grass-covered mounds and ridges (eskers) in the Lucan and Tallaght area of the plain, and the Norman Tymon Castle stands on a small typical esker near Babrothery. Evidence from Europe shows that a dry age followed the final melting of the glaciers. Then came the milder years when bogs gathered in the plain, and- even across the crests of The Leinster Chain, from which they are now being washed or blown away. The tree-stems found in the mountain bogs indicate at least one forest epoch, when the slopes were clad with conifers to heights of 1800 ft. or more.

April 15th, 2008 | Tags: Bray, Co. Wicklow, Dodder, Downs, Dublin, Dublin city, East Leinster, Europe, Glacial, Glacial deposits, Ireland, Irish Sea, Kathfarnham, Killiney, Kings River, Leinster Chain, Leixlip, Liffey, Lucan, Norman Tymon Castle, Pollaphuca waterfall, Scalp, Slade of Saggart, Slievethoul range, Tallaght | Category: Geology | Comments (1)