209 



Fame Islands, a few km from the coast, inside a little valley, 

 the topography of which will be described later in this paper. 

 The rock occnrs here in close connection with the limestone 

 referred to the archaean formation and already described, partly 

 as dikes, partly — at least in one place — as a smallish 

 lenticular mass bordering on a somewhat disintegrated, light 

 granite, from which it is separated by a curious mixed breccia. 

 The granite itself has already been mentioned (p. 169). It is red 

 or reddish yellow, fairly rich in quartz, with considerably wea- 

 thered orthoclase, and moreover it has been subjected to strong 

 pressure. Nearer the line of contact, as far as I could see 

 without any sharp border against the typical breccia, the rock 

 is still more altered, traversed by zones that consist of com- 

 pletely recrystallized crushed mass, which abundantly contains 

 beautiful little rhombohedra, strongly refractive and doubly re- 

 fractive, evidently a carbonate mineral. The felspar, here too, 

 is strongly disintegrated; besides orthoclase there occurs much 

 plagioclase, partly as perthitic intergrowths. 



It is not easy to explain how these changes in the ap- 

 pearance of the granite stand in connection with the basaltic erup- 

 tions. It is not precluded that, connected with these, disloca- 

 tions have taken place. However, that the rocks are not directly 

 divided by a line of dislocation is clear from the two quite dissimilar 

 transition forms which are herewith described. The one is a 

 true fusion rock, acid and fairly rich in quartz; in its mass 

 can be observed numerous angular fragments of green- 

 coloured rocks. Under the microscope one can see that the 

 rock chiefly consists of large crushed quartz and felspar indi- 

 viduals, which show by their appearance that they derive from 

 the surrounding granite; between them there is often a mass 

 which to a great extent consists of needle-shaped felspar indi- 

 viduals and resembles the products of re-fusion and solidification 

 often found at magmatic contacts. In other places a similar, 

 curious mass of limited and local origin is perfoliated by thin 

 -XXVIII. 14 



