Vol. 62, .] GLACIAL PERIOD IX ABEEDEENSHIEE, ETC. 27 



In other parts of the country, the result of the last ice-sheet 

 has generally been to form at the surface a thin covering of 

 coarse mud, charged more or less with stones. In the lower 

 coast-district this lies on the top of the Red Clay, and derives its 

 colour partly from it ; but, along the course of the rivers and minor 

 streams, there is always more or less washed gravel, formed, by the 

 currents generated by the final melting of the snow and ice. 



IX. The Ceag-Shells axd Chalk-Debeis of the Red Clay — 



THEIE DeEIVATIOX. 



The Crag-shells, and the debris of Secondary limestone accom- 

 panying them, which are found in some of the gravel-beds and clay 

 of the Aberdeenshire coast, have evidently been brought thither by 

 the ice-stream which produced the Red Clay, and may therefore have 

 been transported from a very great distance. It has to be kept in 

 view that pieces of chalk, sometimes iceworn and scratched, likewise 

 occur in this Red Clay. They are met with at Montrose, Belhelvie, 

 and also, though rarely, near Peterhead. Small pieces of coal 

 have also been got in the same clay. The Cretaceous fragments 

 have probably been brought to the east coast of Scotland by the 

 Scandinavian ice, which passed over strata of Chalk in part of its 

 route ; and possibly the debris of the Crag may also have been 

 brought by the same agency. 



The bits of chalk are not uncommon in the Belhelvie clay and also 

 at Montrose. It is not likely that they could have come from 

 England, as the movement of ice to the south of the Firth of Forth 

 was such as would have carried them in the opposite direction. 

 Their occurrence at Montrose and Belhelvie tends to prove that 

 this clay in Forfar and Aberdeen is all one and the same deposit. 



The Southeex Boedee of the Moeay Fieth. 



In this district, the valleys have a general trend from south-west 

 to north-east, as will be seen from a glance at any good map. 

 The Ness, the Nairn, the Findhorn, the Spey, the Deveron, are the 

 principal rivers, and they all flow. in this direction. It might 

 therefore be supposed that, during the Glacial Period, the ice would 

 move down to the coast along these lines; but there is ample 

 evidence to show that in some part of that period a great transport 

 of boulders and mineral matter took place along the coast from west 

 to east, right across the lower ends of these river-valleys, while 

 marks left by the ice upon the rocky framework of the country, 

 together with the drift of transported stones, prove that in some 

 places the movement was from north-west to south-east. l 



X. Marks oe Glaciation ox the Rocks. 



The finest display of this sort that I have seen in the district, 

 is on the top of a low hill called the Garden Moor, not far from 



