646 Prof. Bomiey — Roch-specimens from the Canadian Rockies. 



second is a dark limestone, probably tinted by carbonaceous matter 

 and not very pure, which assumes a brownish tint in weathering. On 

 one side portions of four trilobites are exposed.^ The last number 

 covers three specimens from the moraine of the glacier in Ball 

 Valley. One is a rather dark limestone, compact in structure, 

 not unlike some of our Carboniferous limestones, in which are some 

 irregular white spots and occasional white streaks up to about a 

 quarter of an inch in length ; a second is not quite so dark, but has 

 only a few small spots ; the third (smaller) is a prism with natural 

 faces, paler in colour. These two much resemble specimens of 

 British Carboniferous Limestone. A slice from the first shows a 

 mosaic of grains, rather variable in shape and size, and ranging from 

 about '0025 to "005 of an inch in diameter. Most of them are 

 crystalline calcite, but the brighter tints of some suggest the presence 

 of dolomite, or possibly chalybite. The white spots prove to be 

 irregular aggregates of similar but larger grains, often about '02 inch 

 in diameter. The matrix includes a few crystalline grains of a clear 

 colourless silicate, two of which, about -025 inch long, are fairly 

 idiomorphic, being bounded by edges in the prism-pinacoid zone, 

 and those of pyramids or domes meeting at an angle of about 70°. 

 They extinguish at a small angle, about 5°, with the former lines, 

 include a few granules of calcite, and probably are a secondary 

 felspar. [2015], from the summit rock of Ball Pass, is a compact 

 darkish limestone, bounded by four rhomboidal joints, and showing 

 at right angles to these slight signs of lamination. Under the 

 microscope this structure is more conspicuous, for it proves to be 

 composed of granules of calcite, with a faint staining, divided by 

 linear bands of grains, about -0025 inch in diameter, separated by 

 a dark-brown material, and presenting a slightly fragmental aspect. 

 A number of minute cracks, filled with more coarsely crystalline 

 calcite, run at high angles to the banding. This specimen may 

 have been affected by a shearing crush. [2013], from the summit 

 of Mount Francklyn, which rises just north of Vermillion Pass, is 

 an oblong slab, four of its surfaces being natural ; apparently it is 

 a compact, rather muddy limestone, a dull grey, weathering brownish, 

 in colour, with a faint and slightly wavy cleavage, which makes an 

 angle of about 25° with the (natural) top and bottom surfaces of 

 the slab. 



The next group of specimens comes from the Mount Stephen 

 district. This peak lies a short distance to the E.N.E. of Field 

 (4,026 feet), which is a station on the Canada Pacific Eailway a few 

 miles west of the divide. [2011], " from a height of about 6,000 feet 

 on this mountain," is a rather slabby, dark calcareous mudstone, 

 something like Llandeilo Flag, but weathering to a browner tint.^ 



Cathedral Peak [2035], E.N.E. of Mount Stephen (but also west 

 of the divide), is a stratified limestone, the broader bands darkish 

 grey, the thinner weathering to a browner tint, but little streaks 

 with a similar habit occur in the other. Dennis Pass is to the south 



1 For a description of these by Dr. H. "Woodward see pp. 536 and 541. 



2 For a description of the fossils on it see Dr. "Woodward's paper, pp. 529-543. 



