62 James Geikie — On Changes of Climate. 



2. and 3. Moraine rubbish... Eetreat of the great glaciers; erosion of river terraces. 



4. Moraines overlayinar the ) t^t ■, a ^ ■ 



older glacial depolits ) ^^^ ^^^^^'^^ °^ g^^^^^^- 



5. Newer moraines Periodic retreat of glaciers. 



The ground moraines are undoubtedly the exact equivalents of our 

 Till. The Scottish drifts marked 2 and 3 correspond to the moraine 

 rubbish of the Swiss section — the difference between the Scottish 

 and Swiss deposits being only what we should expect when we 

 remember the different conditions under which they were separately 

 deposited. The subsidence that drowned a large part of Scotland 

 produced the Kames, which are made up partly of the old moraines 

 (2) and partly of the Till and Boulder-earth or clay (1). In the 

 Swiss section, No. 4 is the terrestrial equivalent of the shelly clays 

 and erratics of the Scottish series. No. 5 is precisely the same both 

 in Scotland and Switzerland. It will be observed that in the ground 

 moraines of the latter country no inter-Glacial beds, such as cha- 

 racterize the Scottish Till, have been observed. But when we 

 consider how great the chances are against inter-Glacial deposits 

 being preserved, the absence of these from the Swiss Grundmorune 

 need not surprise us. It is quite possible, however, that they 

 may exist, although they have not yet been detected.^ The Scottish 

 Till was studied for many years before its intercalated deposits 

 attracted any attention. Is it too much to say that it may be even so 

 with the Swiss Grundmordne ? 



The succession of the drifts in Scandinavia also agrees generally 

 with that observed in Scotland, and there is nothing in the descrip- 

 tions given of the " northern drift " of Russia, Germany, and 

 Denmark which does not fit in to the. sequence tabulated above. 

 Putting together the results arrived at by several observers, as 

 Sefstrom, Berzelius, Murchison, Forchhammer, Lyell, Erdmann, and 

 others, we get the following : 



Scandinavian Glacial Deposits. 



1. Stony clay, sand and gravel Intense glacial conditions ; general ice- sheet. 



2 ? (Moraines) Eetreat of confluent glaciers or ice-sheet. * 



3. Osar or Asar of sand and gravel. . . Little or no floating ice ; period of subsidence. 



. „, . -ii. 1- J 1, 1 C Advance of s-laciers; period of floating ice; 



4. Clavs, etc., with arctic and boreal ) ,._ , Z- \. >. <. „ „„ij „„ /i\ !?„ 



,•',', X-, - { climate arctic, but not so cold as (1). Ke- 



sheils. Jirratics ^ elevation of the land. 



6. Moraines Eetreat of the glaciers. 



1 have not been able to satisfy myself as regards the position of 

 the "sand and gravel" of No. 1, and therefore cannot say whether it 

 points to inter-Glacial mild periods, like those of which we find such 



^ In a subsequent paper I shall return to the consideration of the inter-Glacial 

 periods of the Swiss geologists, noticing especially the remarkable results obtained by 

 Prof. Heer, see his Urwelt der Schweitz, p. 484, et seq. 



2 From the descriptions given of some of the osar or &ar, I strongly suspect that 

 the equivalent of INo. 2 in the Scottish section occurs in Sweden; but without a 

 personal examination one can hardly be sure of this. MM. Durooher and Martins 

 distinguish two kinds of osar — the one containing scratched stones and some- 

 times shells of Arctic species, and being often made up of very coarse materials; the 

 other being more sandy and showing shells of Baltic species. The former may 

 possibly represent some portion of the Scotch Boulder-earth and clay. 



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