339 
that peculiar subdivision of nepheline-syenites which is repre- 
sented at llimausak, by the rocks described as sodalite-foyaite, 
naujaite, lujavrite, and kakortokite. In the following table the 
rocks are enumerated in order from the top of the batholite 
downwards, with indication of the main divisions: 
|. Granite (arfvedsonite-granite) 
Quartz-syenite 
II. Transition zone | Pulaskite 
| Foyaite 
Sodalite-foyaite 
III. Agpaites Naujaite 
Lujavrites and kakortokites. 
I. The arfvedsonite-granite constituting the uppermost 150 
—400 meters of the stratified batholite is, chemically, related 
to the soda-granites of the Christiania district. The flat under 
surface of this rock body and the gradual transitions to the 
underlying rock lend some support to the view that the granite 
has not been separately intruded, but has originated by differ- 
entiation in place. On the other hand it is difficult to imagine 
any process by which the arfvedsonite-granite could originate 
in situ as a differentiation product of the agpaite rocks which 
now underlie it. 
The question can, however, be viewed in another light. It 
has been pointed out that the stratified abyssal rocks do not 
represent the original filling of the batholitic chamber. At se- 
veral places large masses are left which suggest that the 
original filling was a syenitic magma. It is perhaps not im- 
possible to imagine that the granite in some way may have 
originated from the syenitic magma. Owing to its lower specific 
gravity it may have accumulated at the top of the chamber, 
while both magmas were yet in a semi-fluid condition. For rea- 
sons given above (p. 321) a genetic relationship between the gra- 
99° 
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