1865.] JAMIESON LAST CHANGES IN SCOTLAND. 181 



of it in the flank of the little hiU called Torvane, or Tor Bhain, 

 which seems to be entirely composed of gravel. 



Believing that glaciers occupied the vaUey of the Caledonian 

 Canal both before and after the period represented by the marine 

 beds with Arctic shells, I cannot help thinking they had something 

 to do with the formation of this remarkable heap of gravel ; and if we 

 might believe that the debris brought down by the glaciers was acted 

 upon by the sea beating upon the terminal moraines, it might help 

 to explain the water-worn character of the stuff, as well as the ter- 

 raced appearance which it frequently presents. 



A somewhat similar accumulation of gravel and pebbles, although 

 not so extensive, is seen at the entrance to Loch Treig, and there is 

 also a prodigious quantity of it on the west side of the Spey, near 

 Fochabers. 



In the low grounds away from the mountains the superficial masses 

 of roUed gravel are often of dubious origin, owing to the diflftculty, 

 where no fossils occur, of distinguishing that which is marine from 

 what has been due to subsequent freshwater and glacial action. It 

 seems likely that a good deal of gravel would be formed by the sea 

 while the land was recovering from the depression that took place 

 during the time that the marine clay was forming. If any sudden 

 movements of elevation occurred, there must of necessity have arisen 

 strong currents off the land, with several oscillations, which would 

 effect a considerable denudation of the soft recently formed marine 

 beds, and probably produce a large amount of rolled gravel. The 

 tails of gravel on the seaward side of the rocky eminences near 

 Edinburgh, long ago noticed by Sir James Hall, can hardly be re- 

 ferred to any river-action, and the marks of denudation around the 

 Castle-rock and the base of Arthur's Seat show that some agency must 

 have been in operation, subsequent to the deposition of the fine lami- 

 nated clay near Lochend and Portobello, to carry off the small loose 

 debris and sweep the surface bare. 



At Aberdeen, and to the north of that city, there are mounds of 

 loose gravel which are of later origin than the laminated clay con- 

 taining Arctic shells ; and Dr. Fleming tells us that Agassiz in 1840, 

 on looking at some of these, pronounced them to be moraines. This 

 would imply that the glaciers here extended to the present sea-coast 

 after the deposition of the clay. At Belhelvie, four miles north of 

 Aberdeen, there are remarkable piles of gravel, close to the sea, 

 forming large irregular mounds. This gravel is certainly of more 

 recent deposition than the clay close beside it, which contains Arctic 

 shells (see Appendix), Its boundary to the north, at Millden, is 

 sharply defined, and it seems to be a continuation of the gravel 

 of the vaUey of the River Don, for I have traced it across the low 

 intervening ground into that valley at a place called Dyce, four 

 miles distant, where there is another large accumulation of it. 



The River Don makes a sudden bend to the south at Dyce, and 

 enters the sea two miles to the north of Aberdeen ; but the valley- 

 gravel does not follow it along that part of its course, but goes 

 straight out to sea at Belhelvie, forming a series of mounds all the 



