234 Carl Fred. Kolderup. [Nr. 8 



found several dykes of granite ricli in plagioclase, as is the case 

 in several places of the Bergen-area. ln the phyllite-zone in other 

 places of the Samnanger-area are found fine-grained, schistose saus- 

 surite-diabases, which likely originally either have been tuffs, or 

 small injections-masses, or volcanic currents, come forth through 

 submarine eruptions. 



In several places. as for instance at the turnings of the road 

 which leads from Hisdalen down to Aadland, we have the oppor- 

 tunity of seeing zones of gneisses which ovving to their greater 

 power of resistance stand in steep escarpments, and allow the river 

 to form small cascades. These zones I have not marked on the map. 



Further towards the east, however, we have larger gneiss-areas, 

 designated on the map with reddish colours. The westernmost of 

 these areas extends from Sandvik at Sørfjorden in south-eastern 

 direction up the mountain. Somewhat to the east and with a simi- 

 lar course there is an area which stretches from Sørfjorden to the 

 tracts south-west of the southern end of Fitjevand. A third and 

 considerably smaller zone extends from the south end of Fitjevand 

 to the bay at Aldal. 



The rock in the westernmost of these zones which can best 

 be studied in the cuttings along the railroad east of Sandvik is 

 partly a fine-grained, grey gneiss, partly a micaceous gneiss with 

 eye-structure. In the eastern part there is a crushed gneiss rich 

 in chlorite with numerous small veins of felspar. Under the micro- 

 scope we see a well developed detritus-structure. The larger 

 components consist of plagioclase, microcline and orthoclase. In 

 the detritus-mass we see these masses of felspar together with 

 quartz, muscovite, chlorite, pyrite and zirkon, and partly with some 

 calcareous spar too. 



Also the most central gneiss-zone can best be studied in the 

 cuttings at the railroad. The western part consists of a finegrained 

 micaceous gneiss. Under the microscope we see some bluish-green 

 hornblende, numerous shells of brown biotite. numerous small grains 

 of zoisite as well as felspar and quartz. At the railroad the 

 eastern and more important part consists of banded gneiss which 

 partly has eye-structure. Under the microscope we see that the 

 dark bands chierly consist of a greenish biotite and epidote and some 

 felspar and quartz. The light-coloured bands are mainly composed 

 of felspar and quartz. Some of the larger felspar-eyes consist of 

 plagioclase and microcline. 



