Vol. 62.] THE GLACIAL PERIOD IN ABEL DEENSH1EK, ETC. 13 



3. The Glacial Period in Aberdeenshire and the Southern 

 Border of the Moray Firth. By Thomas F. Jamieson. F.G .8. 

 (Read November 8th, 1905.) 



Contents. 



Page 



I. Introductory 13 



II. The Red Clay of the Aberdeenshire Coast — its Origin and Deri- 



Tation 13 



III. Relation of the Chalk-Flints to the Red Clay 20 



IV. Question of Submergence 21 



V. Succession of Beds — an older Boulder-Clay discovered 21 



VI. The Chalk-Flints of Aberdeenshire 24 



VII. Explanation of the Absence of Shell-Beds in the Red Clay 24 



VIII. The last Ice-Sheet 25 



IX. The Crag-Shells and Chalk-Debris oftheRed Clay— their Derivation. 27 

 The Southern Border of the Moray Firth. 



X. Marks of G-laciation on the Rocks 27 



XI. Transport of Boulders — Jurassic Debris and Chalk-Flints 28 



XII. Extent and Depth of the Ice 30 



XIII. Southern Border of the last Ice-Sheet where it crossed the Spey .. 30 



XIV. Period of Submergence— Shell-Beds 32 



XV. The Dark-Blue Clay of the Banffshire Coast and Northern 



Aberdeenshire 34 



I. Introductory. 



That north-eastern angle of Scotland which lies between the Moray 

 Firth and the Firth of Tay presents some special features of 

 interest in connection with the history of the Glacial Period, 

 inasmuch as it seems to have been less heavily covered with ice 

 than the rest of Scotland. Nevertheless, no part of the area 

 appears to have escaped invasion, for the ice which filled the basin 

 of the Moray Firth extended over all the southern border of that 

 basin, and even overflowed a considerable part of Aberdeenshire, 

 spreading southward until it met those streams which, proceeding 

 from the Grampian Mountains, moved eastward along the valleys 

 of the Dee and the Don. No part of the surface, therefore, escaped 

 abrasion by the ice ; and no remnant of pre-Glacial Tertiary deposits 

 has hitherto been found in any part of the area, even in those spots 

 where one would have thought that they might have been most 

 likely to be preserved. Neither has any trace been obtained of the 

 mammalian fauna which inhabited England during the inter-Glacial 

 Period. No remains of the Mammoth, not even a tooth or a tusk, 

 have been met with in any of the railway-cuttings or other ex- 

 cavations (so far as I am aware), although such have been found in 

 Ayrshire and in the Basin of the Forth. v 



II. The Bed Clay of the Aberdeenshire Coast — its 

 Origin and Derivation. 



One of the most interesting features in the Glacial Geology of 



