718 STEINAR FOSLIE 
Here the granite does not occur as crossing dikes, but as small 
lenses or bands arranged parallel to the schistosity of the amphibo- 
lites. In some cases they occur as separate sheets of considerable 
thickness in or at the border of the amphibolite. Only in rare 
cases, when the amphibolite has retained a more massive structure 
without marked schistosity, do they occur as numerous crossing, 
irregular stringers cutting the femic rock. 
The contrast between the two rocks is still more marked than 
was the case in the Raana field on account of the great difference 
in chemical composition and the different degree of metamorphism. ~ 
While the amphibolites are completely recrystallized, the granitic 
differentiates have retained much of their original structure, partly 
because they are somewhat younger, partly because the granitic 
mineral association has by far not the same tendency toward 
mineral readjustment under new conditions as is the case with 
the femic rocks. 
These granites are characterized as soda-rich, but their compo- 
sition may differ somewhat. Sodium may be quite predominant 
among the alkalies, the rock becoming a Trondhjemite as described 
by V. M. Goldschmidt from the Trondhjem district farther south. 
By increasing potash they get a more granodioritic composition, 
up to a limit with about equal molecular amounts of soda and 
potash. In all cases they are poor in dark minerals and generally 
have aplitic structure. 
They are distinctly different from the ordinary granites in the 
district, which occur as great independent eruptions, and where 
the potash is always predominant. 
The chemical composition of the ordinary amphibolite and its 
granitic differentiate is seen from the analyses on page 719. 
In some cases we meet intermediate rocks between the amphibo- 
litic and granitic extremities, mainly of dioritic composition. 
The variations are never regular, but form ‘“‘schlieric”’ or banded 
alternations in the schistose rock. 
From the foregoing we have seen that the characteristic regular 
differentiation step between the normal norite and the quartz- 
norite in the Raana field has no correspondent in the amphibolite 
series. This is a natural consequence of the fact that here the 
