438 A rctic and A nt arctic Exploitation [part ii 
pedition were the surveys which completed our knowledge 
of the intricate topography of the south-western part of 
the South Shetlands, correcting former work of Ross and 
d'Urville, and discovering much that was new. The 
geological results were of great importance, for they 
point to the connection of Graham Land with South 
America at a recent geological period. Graham Land and 
most of the islands belong to the region of folding and of 
Andine eruptives. The rocks are plutonic and, according 
to Nordenskiold, belong or are closely related to a peculiar 
type of eruptives characteristic of the American cordilleras 
throughout their length. Ross Island and Vega Island 
are volcanic, composed of basalt and lava flows. Paulet 
Island also contains cones of eruption. 
In the fossils of Hope Bay, Dr Andersson discovered 
a very rich Jurassic flora, consisting of conifers, mare's 
tails, and ferns in profusion. In abundance of species 
Hope Bay far surpasses all Jurassic floras hitherto known 
in South America. They are fresh-water deposits. The 
Seymour and Snow Hill formations are Cretaceous. There 
are many ammonites, cephalopods, bivalves, and trunks 
of fossil wood in the sandstone ; there are also birds, and 
a mammal belonging to the Tertiary period. On Cockburn 
Island there was a curious conglomerate of pecten shells, 
formed on basaltic tuff in Pliocene times. 
In Jurassic times the land must have been covered 
with rich vegetation in a mild and uniform climate. At 
Hope Bay the fresh-water lake flora has close affinity 
with the contemporaneous floras of India and Europe. 
After the Cretaceous surface was lifted above the sea 
level, mountain ranges were formed. The South Shetland 
Islands were once a clearly-marked mountain range 
parallel to that of Graham Land, and the Gerlache 
channel was a longitudinal valley. 
During the Miocene period there were violent erup- 
tions causing a great accumulation of volcanic tuff. The 
fauna of this period was closely allied to the Miocene 
fauna of Patagonia. On Seymour Island five new genera 
of fossil penguins and the large cetacean, Zeuglodon, were 
found in the Tertiary beds ; also the impressions of large 
and very distinct leaves of an Araucaria, a beech tree, and 
ferns. 
