James Geikie — On Changes of Climate. 27 



When the land began to sink down, the terminal moraines left 

 behind by the retreating glaciers would be tampered with, and 

 their materials, well winnowed and water-worn, would be re- 

 arranged, so that little or no trace of anything like moraines would 

 be preserved. Here and there, however, we find thick masses of 

 coarse, unstratified moraine-like matter, wrapped round by heaps 

 of marine sand and gravel in such a way as to show that the latter 

 must belong to a later date than the former. The occurrence of 

 these odd masses of coarse moraine debris, surroiinded on all sides 

 by deposits of fine gravel and beautifully false-bedded sand, used to 

 be a great puzzle to me. The difficulty was got over at first by 

 supposing them to be " iceberg droppings," but when several years 

 had bettered my acquaintance with the marine drifts, and I found that 

 boulders almost never appeared inside the Kames, I began to think 

 that my explanation of the moraine-like rubbish was only an 

 " explaining away." By-and-by, however, what appears to be the 

 true solution of the problem dawned upon me. I am now persuaded 

 that this coarse, unstratified debris with angular blocks represents 

 the relics of the huge terminal moraines which the old glaciers must 

 have left behind them on their retreat to the mountains. From 

 the exact resemblance of this rubbish to that of the Swiss moraines, 

 there is no reason for believing it to have been formed in any other 

 way than these have been. The probabilities are strong that the 

 moraine-stuff to which I refer accumulated upon a land-surface, and 

 not upon a sea-bottom. 



After the subsidence had carried down the land to some con- 

 siderable depth, and many or most of the Kames of sand and gravel 

 had been heaped up, the glaciers would once more appear to have en- 

 tered the sea, and bergs and coast-ice to have formed and carried away 

 with them heaps of angular rubbish and debris. It is a nice question 

 whether this entry of the glaciers was caused by an increase of cold, 

 or whether it might not have been induced by the subsidence itself, 

 which gradually brought the glaciers within reach of the waves. 

 Either hypothesis will harmonize with the facts. All we know for 

 certain is that at a late time, when the submergence had already 

 reached some extent, and currents had piled up a vast series of sand 

 and gravel ridges, glaciers reached the sea and shed plentiful crops 

 of bergs. To this date must be referred the solitary erratics which 

 are scattered far and wide over hill and dale in the Lowlands ; and 

 also those great heaps of partially water-arranged moraine-stuff 

 which sprinkle so large an area in the undulating ground about 

 the base of the Galloway Mountains in the south of Scotland and 

 the Grampians in the north. Local glaciers probably existed in the 

 Peeblesshire hills at this time, but none of them appear to have 

 reached to the level of the sea. 



Erelong the re-elevation of the land began. Step by step the 

 country rose out of the waves, the various pauses in the upward 

 movement being marked by a great succession of terraces and 

 shelves at all heights from over 1000 feet downwards. The Kames 

 and mounds appear in some places to have been planed off and their 



