230 ^ arl Fred. Kolrlerup. [Nr. 8 



found in the phyllite- and marble-zone, formerly described. As, 

 owing to the various finds of fossils made. this zone can with 

 certainty be reckoned to stage 5 a, we are enabled to determine 

 the age of the conglomerate : it must be younger than stage 5 a. 

 I have already previously pointed out this faet in my treatise: "Et 

 orienterende niveau i bergensskifrene" (Bergens Museums Aarbog 

 1897, No. XII). 



Through its numerous stretched boulders the conglomerate gives 

 evidence to having been subjected to a strong pressure. In many 

 places we sec how the pebbles are pressed closely together, so 

 that the borderlines between the light and dark boulders often are 

 difficult to discern. In places where the rock has been pressed 

 so strongly that the boulders have been stretched into thin and 

 flat slices, the line between the pebbles and the groundmass seems 

 also to have been effaccd. This is especially the case where both 

 the pebbles and the groundmass are ricli in mica and chlorite. 



The conglomerate can best be studied in the cuttings along 

 the railroad and along the road west of Hisdal. Near this latter 

 place compressed granitic dykes have been observed in the conglo- 

 merate. Figs. 34—38 show us the appearance and structure of the 

 conglomerate. 



As already mentioned, we have at Os the southern continua- 

 tion of the conglomerate-zones from Samnanger, and, as we can 

 see from the general map of the coast-arches of the western part 

 of Norway, pl. III. the outer Silurian series of layers of the 

 Bergen-arches turn from the Os-district eastwarcls along the northern 

 side of the island of Tysnes, there turning southwards along the 

 east side of the island to continuo on the south-eastern side of 

 Stord, and thence to the southern part of Bømmel. In Stord, as 

 well as in Bømmel, there are conglomerates in this zone whieh 

 owing to their petrographical character must be identical to those 

 described above. In this conglomerate Reusch has also found 

 pebbles of marble with corals, which in my opinion must derivate 

 from the marble at Limbuviken; this must. however, with certainty 

 be reckoned to stage 5 a, just as the marbles of the Samn- 

 anger-area. 



