328 
magma has entirely replaced the older füling of the batholitic 
chamber, and as proved by the contact relations at Nunasarnak 
has even advanced beyond the former limits of the chamber 
(see p. 74); on the southeastern and southwestern sides a 
narrow zone of syenite, which now coats the nepheline-syenites 
as an outer shell, remains; and on the western and north- 
western sides of the complex a large portion of the original 
syenite-batholite has been left. This latter portion has later on 
been penetrated by some independent granitic invasions (see 
map, Pl. II. 
The hypothesis also explains the presence of a small rem- 
nant of augite-syenite in the southernmost part of the Ilimausak 
Mountains (at the north side of Tasek) where it rests between 
the arfvedsonite-granite and the roof of the batholite (mentioned 
p. 88). 
THE LUJAVRITIC STRUCTURE. 
Abyssal nature of lujavrites. — The lujavrites of Ilimausak 
are very different in their structural characters to ordinary abys- 
sal rocks. Asa rule they are fine-grained and display a pronounced 
schistosity which has been assumed during the crystallization (see 
p- 166). It is true that coarse-grained varieties also occur, but 
these are quite subordinate. When, in 1892, i undertook the 
examination of these rocks | had not seen the occurrence in 
the field, and from the structure I incorrectly drew the conclu- 
sion that the lujavrites should be regarded as a peculiar kind of 
chilled edge to the coarse-grained repheline-syenites !. 
For the lujavrites of Kola, which are on the whole a little 
more coarse-grained and a little less schistose than those of 
llimausak, a somewhat similar view was enunciated by W. Ramsay 
7 Forhandlinger ved 14. Skandinaviske Naturforskermode. København 1892, 
p. 433. 
