211 



from notes I took at the time, also limestone. All these forms 

 of rock appear, when seen under the microscope, greatly 

 metamorphosed by contact: the granites are surrounded by a 

 fusion zone of new-formed rock with felspar in the shape of 

 thin needles, such as has already been mentioned from another 

 contact-rock. Interesting are the basic rock forms which must 

 originally have consisted of lath-shaped plagioclase and augite, 

 ore and some large crystals, now perfectly transformed, and 

 which must consequently have had a diabasic appearance. 



Remarkable is a new-formed mineral which occurred at the 

 contact with a large fragment of gneiss. It recalls titanite, but 

 seems to have stronger interference colours than that mineral, 

 and in comparison with material from Alnön it is impossible 

 not to be struck by the likeness with the curious mineral 

 baddeleyite, which occurs there. Yet it is scarcely conceivable 

 that this should be met with at the contact with an acid rock, 

 and I have been unable to decide what mineral it is that we 

 are in presence of. 



We will pass on to the description of the pure eruptive 

 rock, which is best revealed in the two dikes. Its appearance 

 is somewhat variable. The ground-mass is dark, basaltic, and 

 in it we come across large crystals, up to an inch in length, 

 of augite and brown mica. But these are somewhat irregularly 

 distributed, now forming the main part of the rock, now solitary, 

 and in the one dike both forms of large crystals are rare, 

 while especially thin scales of mica give rise to a fine por- 

 phyry structure, somewhat recalling the lamprophyric minette 

 rocks from С Fletcher. In the little mass, too, the very large 

 crystals play a minor part, the whole rock here looking more 

 compact. 



It is the last described dike that was the object of the 

 most detailed study, and of which Miss Naima Sahlbom 

 has made an analysis that resulted as follows: 



14' 



