Besides the boulders described by the late Mr Charles Maclaren in his “Geology of Fife and the Lothians,” and also by Professor Geikie in the “Edinburgh Memoir of the Geological Survey,” as having been carried from the Highlands, there are others which would indicate a transport from a different direction.
On the highest summits of the Pentland Hills (Scald Law, Carnethy, South Black Hill, North Black Hill, and others which are composed of various varieties of porphyrites) are found numerous boulders of fine conglomerates, grits, and sandstones, intermingled with a few boulders of quartz, greenstone, and other rocks, all partially or entirely covered by a deposit of peat, which in some places on and near the summits of the hills attains a thickness of nearly six feet. The sandstone boulders vary in size from mere fragments up to large masses which I was unable to dig up.