Reports and Proceedings — Geological Society of London. 573 



at 12,000 feet in North America, 8,000 feet in Europe, and 1,200 feet 

 in South Africa. With these varying heights he correlates the 

 topography of the bordering continents — the sharp divides, open 

 river-valleys, permanent rivers and deltas, of Europe and America,. 

 where the movement has been downward and has almost reached 

 bottom, in contrast with the flat undenuded divides, the steep, narrow 

 gorges, the waterfalls, and the rocky river-gates of South Africa, 

 which is on the up-grade and probably near the top. 



2. "The Glacial Period in Aberdeenshire and the Southern 

 Border of the Moray Firth." By Thomas F. Jamieson, F.G.S. 



One of the most interesting features in the Glacial geology 

 of Aberdeenshire is the Eed Clay found along the eastern coast of 

 the county. It consists of red sediment brought by ice flowino- 

 .along the coast from south to north, which also carries rocks from 

 the coast between Montrose and Lunan Bay. The clay is some- 

 times finely laminated ; at other times it is mixed with stones ; and 

 at times, again, contains esker-like mounds of gravel. It includes 

 fragments of Crag-shells and of Mesozoic limestone. The purer 

 masses of clay seem to have formed in a sheet of water lying in 

 front of the ice, between it and the land, during the retreat of the 

 Aberdeenshire ice, and at a time when the coast was submerged 

 beneath water to a level exceeding 300 feet above the present 

 coastline. Evidence of the northward motion of the ice is given 

 from striae, the transport and removal of flints, and the bending over 

 of the edges of folia of gneiss. The red clay is underlain by a grey 

 clay, and sometimes covered by a similar one. The author has 

 recently discovered remains of a still older, dark indigo in colour, 

 and containing small fragments of sea-shells. This has, however, 

 been swept away in most places by subsequent ice-movement. 

 In Banffshire a fine dark clay seems to have been formed under 

 the same circumstances as the Eed Clay of Aberdeenshire. The 

 only evidence of warm intervals in this part of Scotland is that 

 inferred from the melting away of the masses of ice, which preceded 

 and followed the deposition of the Eed Clay and the shell-beds 

 of Clava. 



On the southern border of the Moray Firth the author gives 

 examples of glacial marking on the rocks, and refers to the 

 transport of boulders, including a huge mass of Oolitic rocks 

 40 feet thick, a mass of clay once considered to be an outlier 

 of Lias, ' pipe-rock,' and the fossiliferous Greensand debris at 

 Moreseat, now considered to have been transported by ice. The 

 ice appears to have been 4,000 to 5,000 feet thick about Inverness, 

 in order to reach to and overflow Mormond in North-Eastern 

 Aberdeenshire. The terraces of gravel found at decreasing heights 

 on the Spey, near Eothes, seem to have been formed during stops 

 in the retreat of the ice. Arctic shells of deep-water type, found 

 in silt-beds south of Eattray Head, give evidence of a period of 

 considerable submergence ; but the recurrence of an ice-sheet 

 appears to have destroyed most of this evidence, as is seen in 

 a section at King Edward. 



