LAMPLUGH : SHELLY MORAINE OF THE SEFSTROM GLACIER. 219 
similar indications of less severe cold have been detected in a few 
plant-remains from superficial peaty deposits. ^ 
For the British glacialist, it is of peculiar service to find in 
Spitsbergen the effect of glacial conditions on stratified rocks 
analogous in structure and texture to those of Southern Britain. 
In nearly all the other accessible regions of present glaciation the 
prevalent rocks are of the hard or massive type ; but over a large 
part of Spitsbergen, including practically the ^^hole region bor- 
dering on Ice Fiord, the formations, ranging from Palaeozoic to 
Tertiar}^ contain thick masses of shale, marl, fissile sandstones, 
limestones, etc., essentiall}^ similar in lithological character to the 
equivalent formations of Britain, from which our boulder-clays 
have been mainly derived. Under arctic conditions these rocks 
crumble down readih^. so that enormous masses of talus are formed 
under all the escarpments (see PI. XXV.) and even on tlie level 
plateaus, while the frosted shales slide down in mud-flo\\ s at every 
thaw. I was everywhere strongly impressed A\ith the huge 
quantity of loose material that lay ready for conversion into 
glacial drift if it should be caught by a recrudescence of the land- 
ice ; and often the material would require very little kneading to 
be made forthwith into a good boulder-clay. 
SPITSBERGEN GLACIERS. 
In West Spitsbergen at the present time the system of 
glaciation is, on the whole, of the Valley or Alpine type, strongly 
modified, however, by the severity of the climate and consequent 
low altitude of the snow-fields. While many of the smaller 
glaciers have their origin in independent snow-basins, most of 
the bigger ones are fed from wide snow-fields w hich cover a large 
portion of the interior plateaus ranging between 1,500 and 3,000 
feet in elevation. These extensive snowfields in many instances 
contain ice-sheds from which separate glaciers radiate in different 
directions ; but they are nearly always dominated by peak\' 
mountain-ridges on which in the summer there is much bare rock. 
In North-east Land, a separate island of the Spitsbergen archi- 
pelago, the conditions are known to approximate more closely^to 
1 See G. Andersson, "Die jetzige und fossile Quartarflora Spitzbergens als Zeugnis von Klima- 
anderungen " ; and A. S. Jensen and P. Harder, " Post-glacial changes of climate in Arctic 
regions as revealed by investigations on marine deposits" ; both in Die Veranderunzev des 
Klitnas seit dem Maximum der letzten Eiszeit (Stockholm, 1910). 
