CHAPTER IV. 
PETROGRAPHY OF THE IGNEOUS 
ROCKS OF THE ILIMAUSAK REGION. 
INTRODUCTORY. 
The igneous complex of llimausak comprises a great diver- 
sity of rocks which prove genetically connected. Furthermore 
the whole complex is dissected in such a way by the deep fjords 
that the arrangement of the rock-bodies, and their geological 
relations on the whole, are exceptionally plainly revealed. The 
complex is therefore of prominent interest from a petrological 
point of view. As moreover a great part of the rocks differs 
considerably from what is known from other places, a complete 
petrographic description would not be inappropriate. For practical 
reasons, however, only the leading types will here be described. 
The petrographical examination of rocks from the region 
considered in this place was based to begin with on the collec- 
tions made by Dr. К. J. V. Sreenstrup during his various visits 
to the district of Julianehaab. A number of specimens from 
these collections was studied during a stay at Heidelberg in the 
winter of 1888—89, and the author is under great obligation 
to Professor ВозЕмвозсн for many valuable suggestions at the 
commencement of the work. That its continuation has been 
greatly promoted by the excellent text-books of Professor Rosen- 
BuscH need hardly be pointed out to the petrographical reader. 
