1914 — 15] Fj eldby giringen raellem Sørfjorden og Samnangerf jorden. 



229 



blastic, the latter structure being especially due to the abundauce 

 of sericite. In some iustances we shall fiud a kind of detritus 

 structure, and at times we see well developed stretch-phenomena. 

 Figs. 18, 26, 32 and 33 show some of the structures. 



As previously mentioned, the chief part of the marbles found 

 are dark-coloured owing to their graphito or graphitoid. Some- 

 times this pigment is quite equally distributed in the mass, at times 

 arranged in streaks, and less frequently we see the structure 

 described by Rosenbusk: "Eine eigenthumlich kuglige Strukturform 

 kommt dadurch zu Stande, dass ganz pigmentreiche Schlieren flasrig 

 sich um sphårische, eiformige oder nachlinsenformige, pigmentarme 

 bis pigmentfreie Gesteinstheile schlingen." 



Whereas the phyllites which in the Os-tracts accompany the 

 marble, often are dim or slightly glossy schists, this is only the 

 case with few varieties in the zone which I have described here, 

 thus for instance the dark coaly phyllites by the railroad. The 

 other varieties show greater contents of mica so that some of 

 them must almost be said to form a transition between phyllite 

 and mica-schist. As a result of this strouger metamorphism it 

 is impossible to flnd fossils in the phyllites between Sørfjorden and 

 Samnangerfjorden, and if we go to Osterøen and to the continent 

 north of this island we shall see that the phyllites become still 

 more metamorphosed, so that they here strongly approach the mica- 

 schists. In the phyllites at Os Dr. Reusch has, as we know, formerly 

 found trilobites, cup-corals, chain-corals, brachiopodes and graptolites, 

 and later on I have also made several tinds of fossils there. 



The Polymict Conglomerate. 



(Pages 91 — 100.) 



This rock is identical to the conglomerate from the Os-tract, 

 formerly described by Dr. Reusch in "Silurfossiler og pressede 

 konglomerater i bergensskifrene''. Light-coloured granites, defici- 

 ■ent in mica and rich in plagioclase, gneisses, quartzites, marbles, 

 hornblende-schists, green-schists, schistose saussurite-gabbros and 

 epidote-rocks often occur as pebbles. Pebbles of marble are com- 

 paratively rare, they offer, however, much of interest; thus the 

 marble which occurs as blocks in the conglomerate in Osterøen as 

 well as south of Sørfjorden seems to be identical to the marble 



