14 
sandstone rests directly upon the Julianehaab granite, and its 
lowermost layer has usually the character of an arkose. The 
total thickness of the sandstone formation is about 1200 meters, 
that of the volcanic series about 1000 meters. The sandstone 
is supposed to be of Devonian age, but as the correctness of 
this supposition has not been definitely proved it would be ad- 
visable to have a local name for this formation. The name 
“igaliko Sandstone” has been chosen because Igaliko is the 
only place within the sandstone area which is inhabited. 
Distribution. — We cannot doubt that the Igaliko Sand- 
stone and the volcanic series must originally have had a wide 
extension in South Greenland. Even at the present day isolated 
sandstone areas appear to exist in several places in the ice- 
covered interior as may be inferred from the not uncommon 
occurrence of boulders of this rock in recent moraines of the 
inland-ice. But in that part of South Greenland which is free 
from ice, both formations have now a very inconsiderable ex- 
tension and do not occur beyond the limits of the map, Plate II. 
Since some of the main occurrences will be described more 
fully in the following chapters it will suffice in this place to 
give a general account of these formations and a discussion of 
their geological age. 
The total area of the Igaliko Sandstone may be reckoned at 
about 200 square kilometers. The largest part of this area lies 
between the Fjords Sermilik and Tunugdliarfik. Another impor- 
tant sandstone area surrounds the head of Igaliko Fjord, and a 
few isolated patches of the sandstone are found near the outlet 
of Tunugdliarfik Fjord, between Narsak and the head of Kangerd- 
luarsuk Fjord. The volcanic rocks are entirely restricted to 
the peninsula between Sermilik and Tunugdliarfik where they 
cover an area which is less than one-fourth of the sand- 
stone area. 
The present boundaries of the sandstone area are of diffe- 
rent kinds from a geological point of view. Towards the south- 
