1914—15] Fjeldbyg ilingen mellem Sørfjorden og Samnangerf jorden. 217 



des westlichen Norwegens II", most of these rocks were intruded 

 during - the Caledonian-Scandinavian mountain-folding. 



The curved arrangement of the series of the strata, as well 

 as of the igneous rocks, is, as we have seen, the distinctive cha- 

 raeter of the region which, in a more limited sense, we should call 

 the Bergen district, or the district of the Bergen arches. It is 

 plain from what has been said about the gneiss-area of Ulrikken 

 that it is not easy to explain its peculiar geotectonic relations. The 

 conditions in the peninsula of Lyderhorn and in the part of Askø 

 situated nearest to the peninsula, where there is a stretching structure in 

 an east-north-easterly direction, seem to suggest the participation 

 of the Bergen arches in the ancient Caledonian-Scandinavian moun- 

 tain-folding, where, on the whole, the folding-axes had a north- 

 easterly to south-westerly direction. 



The district of the folding-zone here called the Bergen arches 

 was after this folding perhaps as a great synclinal pressed in 

 betvveen the western and eastern Archæan areas; the gneiss-area 

 of Ulrikken must then be considered as a younger division corre- 

 sponding to the sparagmite division in the Norwegian mountains. 

 But it may also be that the Silurian arches represent two different 

 synclinals, with a strongly pressed Archæan area between them. 

 During the last folding, the above-mentioned younger eruptives were 

 intruded. A third supposition is, that already during the general 

 main folding, by overlappings or other processes, the different parts 

 of both arches — the inner and the outer Silurian arch — as well 

 as the gneiss-area of Ulrikken have been brought into the present 

 stratigraphical relations to one another, and then by a later process 

 they were, in a body, pressed downward in a direction almost verti- 

 cal to the former folding-axes. 



The Mapped Tract between Sørfjorden and Samn- 

 angerfjorden. 



(Pages 14—17.) 



The map (pl. 1) represents the tracts lying between Sørfjorden 

 to the north and the northern branches of Samnanger fjorden, 

 Trengereidfj orden and Aadlandsfjorden, to the south. 



In the western part of the district we tind the slopes of the 

 highest mountain of the Bergen-area, Gulfjeldet, which rises to a 



15 



