1896.] GEOL. IAGTTAGELSER I TELEMARKEN O. S V. 101 



shown on pag. 32. I have described similar hills from ari other 

 region and tried to give an explanation of their origin (Chri- 

 stiania vidensk.-selskabs forhandl. 1896, no. 1, s. 11.) 



Numedal and Hallingdal. Dal means valley. Maps on p. 

 4 and 34. The general slope of the land on the East-side 

 of the high plateaus in Southern Norway is toward the SE, 

 but the upper parts of the valleys here in question are run- 

 ning ENE probably due to an inclination of the district in a 

 remote geological period. On pag. 35 are some views from 

 Numedal. The whole region is Archæan but not yet much 

 studied. 



The chief result of the authors studies was, that the Tele- 

 mark-formation with its true clastic rocks (conglomerate) was 

 shown to extend over the middle part of Numedal to Hallingdal. 

 A rock, which is frequently met in some parts, is „the Dagali- 

 gneiss", gray, showing a fine grained groundmass with scattered 

 felspar crystals of about 2 — 3 mm. Some varieties are peculiar 

 containing rather big hornblendecrystals and grains of magnetic 

 iron-ore. In the environs of these latter the black mica is 

 absent from the groundmass, and in section one sees the rock 

 full of white spots, everyone with a dark dot in the middle of 

 it (fig. pag. 36, natural size). Kindred to this gneiss is another 

 one, middlegrained, gray and reddish containing magnetite and 

 amphibole. The small lines in the figure pag. 49 are scales 

 of black mica. The amphibole crystals stand as shown in 

 the figure often in an oblique position in relation to the 

 parallel structure of the rock, as this is marked by scales 

 of mica. 



Fig. 39 shows a lake; the winter ice has pushed up stones 

 along the swampy borders. There are formed low ramparts, which 

 produce small lagunes (L) at the mouths of the brooks running 

 into the lake The undermost figure shows the rampart 

 partly covered with pieces of peatmoss (T) broken up of the 

 marsh (Jf). 



Two giants kettles joined together have made the natural 

 bridge seen on p. 46. The rock is quartzite. 



