Page:Quarterly Journal of the Geological Society of London, vol. 29.djvu/272

 ice-marks, all the rocky hills are glaciated from top to bottom. From the fork at Derreen House stride can be followed along the shore to the mouth of KiBmakillogue harbour, where they bend south-westwards, and run parallel to the ridges of Boulder-clay. Up to the top of Knock-a-tigh, 1100 feet, striae were copied off the rocks by rubbings. Near the top is a large perched block. At the base long deep grooves run under the long ridge of Boulder-clay. As I read this record, it means that ice flowed off this long ridge, as water flows off a roof, till it got into Kenmare river and the other gutter, Bantry Bay; then it flowed seawards S.W. 2nd. Small local glaciers afterwards cut through the ridges of Boulder- clay which were left by the large Kenmare-river glacier, and so opened the harbours of Kiilmakillogue and Scriob. The ice was more than 1100 feet thick in Kenmare river, and it probably was a great deal thicker; for the whole ridge is glaciated. Crossing the corresponding gutter to the opposite side of Kenmare river, all these marks are repeated at the corresponding harbour, and they recur down to Dursey Island ; there the sea is breaking cliffs out of the hills. At Bally-na-Skelligs Bay all known glacial marks occur, as they do at Valentia. Three great sea-loughs at least, Bantry Bay, Kenmare river, and Dingle Bay, were the beds of enormous glaciers, which came from hills about Killarney as rivers do now. There can be no question as to the former existence of a great local ice-system in the south-west corner of Ireland. But when the northern half of Ireland was covered with ice, the Kerry system must have been joined to the system which flowed seawards at Galway and at Carlingford Lough. All these sets of facts combined prove that all the local systems in Ireland were united before they broke up into separate local systems. Join high glaciated points, change lines into planes, and the whole area of Ireland is beneath the level of ice which ground heavily on hill-tops more than 2000 feet higher than the plain.

9. United Irish System. — Since I first observed bigh ice-marks in 1863, many Irish observers have tested my facts published in 1865. In an able paper upon the glaciation of Ireland, published in the first volume of the ' Transactions of the Irish Geological Society,' the Rev. Mr. Close says that he found that which I had found upon the top of Shan Folagh.

Mr. Kinahan, the local geological surveyor in the district, sought for like marks on neighbouring hill-tops, and found them. His work, begun about 1865, was published in 1872. Messrs. Close and Kinahan have now published a pamphlet with a map of glacial marks about the heads of Clew Bay and Galway Bay, Lough Mask and Connemara. This map of the able and patient work of seven years confirms my own rapid observations. There was a very large local glacier-system in Western Connaught, which radiated seaward, and which joined other systems on the landward side, till it dwindled away there as elsewhere. It left an exceedingly complicated record in the low grounds, where systems met as glaciers did at Dorreen in Kerry, or where systems split behind hills. Taking the whole