198 PROCEEDINGS OF THE CANADIAN IN^t'lTUTE. 



blende, banded grey hornblende and quartz-rock with some layers 

 approaching chert, mica schists of different kinds, mixed hornblende 

 and mica-schist, chocolate-coloured porphyry with flesh-coloured 

 crystals of felspar and grains of clear quartz, graniilite, red jasper 

 with dull fracture, hard brownish-red sandstone, grey felsitic quart- 

 zite with lenticular patches of dark mica-schist, chloritic schist, the 

 granular iron pyrites associated with dai-k-greenish schist above 

 referred to, several hundreds of cubes of iron pyrites, mostly small, 

 taken from a dark glossy schist, quartz- veinstone with large scales of 

 light-coloured mica together with garnets, calcspar veinstone with 

 embedded crystals of quartz and having grey steatitic rock adhering 

 to it, also "a veinstone of quartz containing silky radiating; aggregates 

 of hornblende and a few specks of calcspar and iron pyrites ; some 

 greenish schist is attached to this specimen. A loose piece of brown- 

 weathering dolomite with reticulating strings of white quartz was^ 

 found on Marble Island. 



The granular quartziferous iron pyrites of this collection bears a 

 strong resemblance to that of the mines at Capelton, in the Township 

 of Ascot, Province of Quebec, and to that of the more cupriferous 

 pyrites of the Tilt Cove Mine in Newfoundland, as also to the equally 

 rich copper-bearing pyrites more recently discovered among the 

 Huronian rocks at Sudbury, in the Province of Ontario. The speci-' 

 men of pyrites from Inari did not show the presence of copper, but 

 elsewhere in working pyrites veins it has been observed that although 

 this metal niay be present only in small quantities at the surface, the 

 proportion increases rapidly in going downward. 



The resemblance between the pyrites bf the three localities above 

 mentioned is interesting, not only from an economical, but also from 

 a geological point of view, especially in connection with the question 

 of equivalency iri age, or otherwise, of the diffei-ent sets of rocks in 

 which they are found. 



At the south-west point of Marble Island, large green stains of 

 carbonate of copper occur on the surface of the quartzite, some of 

 them being three or four feet in diameter. They are probably due to' 

 the decomposition of sulphide of copper in the rock. 



In 1850, James Tennant, Esq., Professor of Mineralogy, in King's. 

 College, London, examined seven rock-specimens which had been 

 brought from the north point of Rankin Inlet, directly opposite to and 

 in sight of the west end of Marble Island, and among them he men- 



