78 A DESCRIPTION OF THE [Ch. V. 



between gneiss and mica-slate ; passing, on the one hand, 

 into the former by an increase of felspar ; and, on the other 

 hand, into the latter by the disappearance of this mineral in 

 a distinct form. 



On the height of Stordalen, the undulations of the mica- 

 slate may fairly be compared with the waves of a stormy sea ; 

 they are so large and long, and rise and fall in such a man- 

 ner, that it becomes extremely difficult to discover, from these 

 slates, the inclination of the strata. Besides, the surface of 

 these curves is so wonderfully indented, that the slates appear 

 to be fixed into each other like swallow-tails ; and this struc- 

 ture prevails throughout the whole length of the mountain. * 



At Bergen, the mica-slate first follows the great gneiss 

 formation ; then comes the gneiss of the islands, in which 

 beds of mica-slate are very frequent ; and this is again suc- 

 ceeded by mica- slate, of a nature which approximates to clay- 

 slate, f 



Around Forvig the mica- slate does not contain felspar, but 

 envelops beds of white limestone. This continues to the foot 

 of the mountain, Bevelstadsfieldt, where felspar makes its 

 appearance in large shining crystals, which nearly displace all 

 other ingredients ; and the slaty texture disappears. By far 

 the greater number of these crystals lie parallel to each other, 

 dipping towards the east at 60, exactly similar to the adjacent 

 mica-slate. The mica between the felspar is black, and never 

 continuous ; and the quartz is not abundant. This granite is 

 of great extent, not in a single bed, like the gneiss with the 

 large crystals of felspar at Kongvold and Drivstuen ; for, from 

 the foot to the top of the mountain, a height of more than 

 1600 feet, its continuation is scarcely interrupted. In this 

 granite, large crystals of tourmaline are not rare, surrounded 

 by mica : there is no hornblende, but a few black beds, 

 especially near the summit, consist of fine mica, interlami- 

 nated with a little felspar, and a few thick beds of quartz. :f 



* Travels through Norway and Lapland, p. 117. 

 f Idem, p. 132. t Idem P- 137 - 



