the volcanic series now existing at Ilimausak is about 1000 
meters, but there is evidence that the original thickness was 
several times as great. 
Volcanic sheets, sandstone, and basement granite alike 
have been invaded by Plutonic rocks which are now exposed in 
two separate areas. The Jlimausak complex of abyssal rocks 
is the westernmost of these areas, while the Zgaliko complex is 
situated farther eastward and immediately adjoins the inland ice. 
The most conspicuous feature of both complexes is the pre- 
sence of a great Plutonic rock-body of batholitic habit. The 
distance between the eastern margin of the Ilimausak batholite 
and the western margin of the Igaliko batholite is about 27 ki- 
lometers. 
The consolidation of the batholites was later than the 
formation of any part of the volcanic series which now remains. 
But as the composition of the two suites of rocks is closely 
related, it is probable that both belong to the same cycle of 
igneous activity. Some observations suggest, too, that the 
abyssal rocks may have consolidated before the final cessa- 
tion of lava outpourings at the surface. The geological age 
of the batholites, therefore, is also assumed to be late-Devo- 
nian. — 
Of the long succession of geological periods which sepa- 
rate the close of this igneous activity from the Quaternary ice 
age no substantial records have been detected in southern 
Greenland. It is probable, therefore, that during late-Palæo- 
zoic, Mesozoic, and Tertiary periods the country has been ele- 
vated above sea level. During this time the greater part of the 
volcanic series has been removed, and only in the peninsula 
between Sermilik Fjord and Tunugdliarfik are the remnants 
still preserved. The reasons why remnants have escaped de- 
struction there are, firstly, that they have been sheltered by 
local subsidence, and secondly, that they have been much 
altered by contact metamorphism, thus acquiring an augmented 
