174 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 31, 



are seen, as if protruding from large supplies behind. We also see 

 a small vein of granite, not more than a few inches thick, losing 

 itself in the grainless gneiss at top. We have lastly some gneiss 

 showing itself in a very peculiar shape, and becoming grainless when 

 near the granite. The general foliation of the limestone and gneiss 

 seems to agree. The section, fig. 1, p. 167, would cut across this at 

 the extreme right of the diagram where the distortion is least. 



(Case 10.) — Besides the more regular beds of limestone here de- 

 scribed, several apparently quite detached pieces (varying considerably 

 in size) may be seen completely surrounded by the gneiss. Fig. 6 

 represents the shape of one of these detached masses * . The limestone 



Fig. 6. — Outline of one of the detached limestone-masses in gneiss 

 at Jcegersborg, near Christiansand. 



is precisely similar to the other, and is foliated by the same minerals 

 as in the last case ; and even here the lines of foliation in the gneiss 

 appear to be carried out without disturbance through these lime- 

 stone-masses. 



(Case 1 1 .) — A very interesting arrangement of the foliated struc- 

 ture, very similar to that of the garnets in mica-schist, was found 

 by me at Lindflid, on the borders of Ongsteens lake, between Brats- 

 berg and Nedeness Amt, in Norway, and apparently extending over 

 a considerable area, probably of some square miles. The rock here is 

 a species of talcy mica-schist, and contains innumerable nodules of 

 dichroit, of a white or bluish-white colour, sometimes exhibiting the 



Fig. 7. — Mica-schist with nodules of Dichroit, Ongsteens Vand, 



Norway. 



pecuHar and characteristic play of colours. These nodules are nearly 

 of a size, about that of a walnut, and the foliation of the mica bends 

 itself around them, producing a very peculiar appearance from the 

 immense number of the nodules present and the extreme regularity 

 of their disposition, which can be seen at a glance. 



The whole would appear as the effect of some arranging force, in 

 conjunction with the ordinary action of foliation. 



The cases of foliation which I have hitherto brought forward have 

 been all caused by the introduction of silicates, but in many cases I 



* Scheerer also has some remarks on the occurrence of these masses of lime- 

 stone at Christiansand, N. Mag. f. Naturv. vol. iv. part 2, p. 158. 



