340 



The Scottish Naturalist. 



with a due spirit of preparedness for another period of depression, 

 for Thomas the Rhymer has warned us that : — 



" Bonny Munross will be a moss 



When Brechin's a borough town, 

 An' Forfar will be Forfar still 

 When Dundee's a 'dung down.' 



Turning, however, again to our Gaelic dictionary, we find that 

 the word "Muin" signifies the "back, top, or neck," and it seems 

 to me probable that the word Montrose was originally Muinross, 

 or the back or top of the promontory or isthmus. 



GEOLOGY OF MONTROSE DISTRICT. 



Leaving, however, for the present these abstruse philological 

 speculations to more competent students, let us turn to our 

 geological record and see what it tells us of bygone times. The 

 most recent stratified rock underlying our superficial deposits is 

 the newer beds of the old red sandstone, as seen at Hedderwick 

 quarry, and is reached by borings in the town at a depth of from 

 100 to 200 feet. On either side of the valley erupted trap forms 

 ridges of hills lying from S.W. to N.E. Of the existence of any 

 newer rock than the Old Red we have no evidence; and, so far as 

 we can judge, the denuding action of the Ice Age was exercised 

 directly on these secondary rocks, over which lies the red tile or 

 Boulder Clay, in which we find rounded stones, or bools, as they 

 are locally called, derived from the conglomerate. 



When the rock surface is exposed, we find it scratched and 

 polished in a general direction from west to east. The great 

 sheet of ice which we have reason to believe enshrouded the land 

 during the early glacial epoch, while gliding slowly to the sea 

 level, acted as a great planing machine, under which were em- 

 bedded the stones, sand and clay of the least-resisting rocks. 

 These scratched and grooved the harder rocks over which they 

 passed, while the harder bools of quartzite, etc., got scratched in 

 their turn by the rocks over which they moved. The gradually 

 accumulating mass of stony clay carried under the ice was de- 

 posited in hollows, and on the lee side of hills. On the Garvock 

 hills, as well as on the high lands of Rossie and Kinnell, we find 

 the north-west aspect bare and polished, the conglomerate being 

 cut across as if by a great sharp knife ; while the south-east or lee 



