Bd. III: 2) CONTRIBUTIONS TO THE GEOLOGY OF THE FALKLAND ISLANDS. 
35 
terrace traversing the stone-river on the slope of Mount Low, together with several 
other facts, makes it highly probable that the raised beaches are much more recent 
than the stone-rivers. As the period of extensive solifluction is considered as an 
extra-glacial facies of the ice-age, we are led to the conclusion that the now parti}' 
drowned river-valleys were formed in preglacial times and that the raised beaches 
are of postglacial age. 
According to the interpretations given above, the geographical development of 
the Falkland Islands can be summarized in the following words: 
In preglacial times this region %vas situated possibly yp in. higher than at 
present., and then there zvas a single large island surrounded by only some fetv 
small islets and rocks. At that time considerable rivers, to udiich there are no 
equals in the present islands, floived in the Salvador, the Choiseid, the Falkland 
Sound valley and several other nozv submerged valleys. 
During the ice-age the level of the island group was at least as high as to- 
day. Whether the islands also during that time remained on a higher level than 
at present, may be settled by future researches into the possible extent of the stone- 
rivers underneath the sea-surface. 
In postglacial times the group ivas submerged at least about yo, possibly ny 
m. underneath its present position, then forming only a sparse archipelago consisting 
merely of small islands. 
To the above notes on the changes of level in the Falkland group I have only 
to add some few words on the most recent development of these islands. 
As has been mentioned already in the introductory chapter, there is, owing to 
the present cool and moist climate, an abundant growth of peat, not only in the val- 
leys but even on the slopes and tops of the hills and ridges. Only in one place, in 
a small peat-deposit some few metres above sea-level at Port Darwin in the inner- 
most part of Choiseul Sound, I studied the structure of a Falkland peat-bog. The 
peat, resting upon fine clayey sand, had here a thickness of 2.^ m. The lower 
part, I m. in thickness, was light greyish yellow in colour, rapidly darkening when 
exposed to the air, and consisting merely of mosses. The upper part, l.^ m. thick, 
black to brown in colour, is composed of mosses intermixed with fragments of 
some bush. 
Though I made repeated inquiries, I never heard of any occurrence of wooden 
trunks in the Falkland peat-bogs. Such a find, when once made, would certainly 
have been widely reported in this completely woodless country. 
