T. S& Hunt on Norite Rock. 185 
By referring to the geological map just mentioned, it will be 
seen that these so-called gabbros occupy considerable areas in 
of Norway. 
the maps, Messrs. Kjerulf and Dahl, these gabbros are regarded 
tonic origin. 
The specimens of these norites exhibited in Paris were in 
blocks polished on one side, and as was observed in the note 
aid of a black diamond, has been in the Museum of the Geo- 
logical Survey of Canada since 1856. 
Of the collection of norites from Norway the specimens from 
Sogndal and Egersund presented fine varieties of grayish or 
brownish violet tints, while a dark violet norite came from 
‘eroé and also from the islands of Langoé and Gomoé, and 
a white granular variety from the gulf of Laerdal-in the diocese 
OF Bergen. 
It is oy in rare cases that the cleavable 2a of these 
ibits the peculiar opalescence which distinguishes 
the finer labradorite found in some parts of the coast of Labra- 
dor. Opalescent varieties of this feldspar are however occa- 
sionally met with in the area near to Montreal, and in northern 
New York. In the Paris Exhibition of 1867 there were 
d, comes from a 
mountain mass in the Government of Kiew, but of its geognos- 
tcal relations I am ignorant. a Le 
_ these peculiar labradorite rocks, presenting a great similarity 
Mm mineralogical and lithological character, have now been 
observed in Essex county, New York, and through Canada at 
Fragile from the shore of Lake Huron to the coast of Labra- 
ee | 
in the Isle of Skye, in Norway, and in southwestern Russia, 
and in nearly all of these localities are known — in oe 
With and apparently reposing like a newer formation upo 
the ancient Lagrentiin, panes " Giekie in his memoir on the 
Seology of a part of Skye,* appears to include the norites or 
; * Quar. Jour. Geol. Soe., xiv., p. 1. 
