FIELD OBSERVATIONS IN NORTHERN NORWAY 715 
“The wave of crystallization is followed by a wave of squeezing.” 
Continually the squeezed material will mix with the more fluid 
magma inside, which gradually becomes more acid. 
The next step is the abrupt transition from the normal norite 
of the marginal zone to the quartz-norite of the central part. This 
is very easy to explain. It represents the stage when the outer, 
solid shell has grown sufficiently thick and strong to resist the 
compressing forces. From that moment no more compression and 
no more squeezing takes place. The remaining magma crystallizes 
quietly without further differentiation to a unitorm quartz-norite, 
carrying a little free quartz and orthoclase, more acid plagioclase, 
and much biotite on account of enrichment of the magmatic water. 
Of course, the contraction or the release of pressure continues 
as the crystallization proceeds, and finally results in a general 
formation of fissures in all directions, when the resulting stresses 
have grown sufficiently strong. 
This fissuring obviously occurred at a stage when the quartz- 
norite was consolidated, with exception of the very last interstitial 
liquid, containing a considerable proportion of magmatic water and 
mineralizers. The liquid was drained into the fissures, forming 
aplitic dikes of soda-rich granite. This last separation is obviously 
not due to squeezing; but whether the liquid was really sucked out 
into the fissures or driven out by the pressure of the enriched 
gaseous mineralizers is difficult to tell. At any rate, there resulted 
a direct connection between these dikes and the last consolidated 
minerals in the quartz-norite, producing the slightly blurred con- 
tacts mentioned above. 
' Also in the marginal normal norite, clefts were formed at this 
period and filled with the same dikes of granite. Here they have 
razor-sharp contacts because the marginal rock at that time was 
completely solid. 
The mineralizers once more separated out, carrying with them 
much potash and silica and giving rise to veins of pegmatite and 
pure quartz, both rich in tourmaline. 
From the foregoing we see that the theory as modified covers 
all the observed facts. It is beyond doubt that the differen- 
