Geology in Derry
About 3 miles to the east of Derry (Self Catering, Derry, Ireland) is the small glen of Lincairn. This gorge is 100 ft. deep and about two-thirds of a mile long, and has a level bottom. This must have been an overflow channel begun at a time when the Faughan valley had 250 ft, of ice in its bed, thus obstructing the drainage in that direction. The curious steep-sided pools that are met with in the gravels and sands on the right bank of the Foyle Kettle-hole, two miles N.E. of Derry (Accommodation, Derry, Ireland) north of Derry, mark the places where lobes of ice became separated from the main body of the glacier. Sands and gravels were deposited over and around them, and afterwards when melting took place, these kettle holes, as they are called, were formed. At the close of the glacial period the land was higher than now, for we have, in addition to the geological evidence, that of the relict fauna and flora, for believing that a land connection with Norway remained after that with the Continent by way of France was broken. Then came a depression that allowed the sea to re-enter certain of the river valleys of the north. Carlingford Lough was thus invaded, and Belfast Lough extended farther to the west than now, and the estuarine clays on which the lower part of Belfast now stands were laid down. An old shore line can be traced from Belfast round the Derry and Derry (Holiday Apartments, Derry, Ireland) coasts, showing that at this time the sea stood some 25 ft. higher than it does to-day. Afterwards, an uplift occurred that brought the sea to its present position and exposed the stumps of ancient forest trees and the peat of formerly submerged bogs.
