Vol. 52.] COL. K. W. FEII/DEN IN ARCTTC NORWAY, ETC. 743 



Quartz, felspar, and biotite are readily seen. The powder shows 

 the felspar (orthoclase probably predominating-) to be rather full 

 of minute enclosures ; also very dark-coloured biotite, with some 

 white mica, a little garnet, and (?) epidote. 



(12 — June ^6th.) A rather coarsely crystalline, reddish granitoid 

 rock, with much felspar. A slice shows the following minerals : — 

 (a) quartz, in grains of moderate size and irregular outline, gene- 

 rally composite ; in it hair-like microliths and small fluid cavities 

 with bubbles are rather frequent, (b) Felspar in grains variable in 

 size and interrupted by inclusions. Microcline is common, but the 

 other grains, as a rule, show no signs of twinning. Occasionally 

 they are rather decomposed, and contain many flakelets of colourless 

 mica irregularly disposed. Also in parts towards the outside they 

 seem to break up into a mosaic of granular felspar, with au occa- 

 sional trace of micropegmatitic structure. The inclusions men- 

 tioned above are sometimes quartz, sometimes felspar, the latter 

 seemingly a different variety, (c) A ferro-magnesian mineral, irre- 

 gular in outline, inclined to be opaque, which in most, if not in all 

 cases, is biotite. A small quantity of a light-coloured mica, which 

 not improbably is a bleached biotite, also occurs. (d) In one 

 part of the slice two or three small patches of a more decomposed 

 mineral, intercrystallized with the felspar, suggest the possibility that 

 a little elaaolite may be present. There is a little apatite and haema- 

 tite, and a grain or two of a colourless mineral, possibly andalusite. 

 The mosaic structure in the quartz and the felspar is not improbably 

 the result of some secondary change, perhaps due to pressure, but 

 not to actual crushing. From the general appearance of this rock 

 I should infer that it is of Archaean age. 



(21.) A moderately coarse, rather felspathic granite. The powder 

 shows quartz, felspar (orthoclase, microcline, and a little plagio- 

 clase), two kinds of mica, one being a dark biotite, the other (in 

 small amount) having a very light-brown colour. 



(22.) A fine-grained dioritic rock — felspar nearly white, horn- 

 blende (abundant) nearly black. Examination of a slice shows that 

 rather more than half the rock consists of a rich green hornblende, 

 which is strongly pleochroic, irregular in outline, including occa- 

 sionally grains of water-clear felspar, iron oxide, and (?) sphene. 

 Small cylindrical or plate-like inclusions of a dark brown colour 

 also are frequent, like those common in diallage, hypersthene, etc., 

 arranged parallel with tho planes of oo P. The intervals between 

 the hornblende are occupied by small, rather irregularly-shaped 

 grains of felspar, often water-clear (possibly in some cases quart/.), 

 together with a nearly colourless epidote. Both the hand-specimen 

 and the slice exhibit a slight approach to foliation. A considerable 

 amount of secondary mineral arrangement is suggested by fcho 

 structure of the rock, but there is no definite evidence that this has 

 been the direct result of pressure. 



