4 
DISCUSSION OF FORMATIONS 
Spray River Formation (Triassic) 
An alternation of heavy-bedded, light grey, calcareous sandstones 
and thin-bedded, dark grey, calcareous-arenaceous shales. The latter are 
especially conspicuous for their numerous black lamina. The shales often 
weather reddish. At frequent intervals throughout the entire thickness 
occur many ripple-marks, mud-flows, minor crossbedding, and mud-cracks. 
The contact with the Fernie shale above is apparently very abrupt, 
though the exact contact was not seen. The topmost hundred feet of the 
Spray River is a light grey, heavy-bedded, calcareous sandstone, whereas 
the lower Fernie is an alternation of black, very fissile shale and almost 
black limestone. The contact with the Rocky Mountain quartzite below 
is plainly seen in the Mount Aylmer region; here the two formations are 
apparently conformable, but the change from quartzite to arenaceous 
shale is rather abrupt, with a very conspicuous development of iron con- 
cretions for 5 or 6 feet at the contact. 
Marine fossils occur throughout most of the formation, though locally 
restricted. They are often found in beds varying from 2 to 6 inches in 
thickness, although above and below they may be apparently entirely 
absent. They are very poorly preserved and the species are confined to 
Lingulae and pelecypods. 
Good collecting grounds for the Lingulae occur about a fourth of a mile 
west of the bridge over Cascade river near lake Minnewanka. They lie 
about 450 feet north of the road upon the eastern side of a ridge, which is 
bounded east and west by swamps. The best place noticed for collecting 
pelecypods is in a 3-foot bed in a half cut upon the north side of the road 
100 feet west of locality 10, section 1. 
Rocky Mountain Quartzite ( Permian ) 
An alternation of light grey quartzite and light grey limestone, the 
former predominating in the upper part, the latter in the lower where it 
merges imperceptibly with the Rundle limestone. The uppermost 50 feet 
contains considerable conglomerate, with rounded quartzite and calcareous 
pebbles up to 2 inches in diameter. 
The formation is fossiliferous at intervals throughout its entire thick- 
ness, but mostly in its upper and lower parts. All the fossils are of marine 
origin. About 10 feet below the top is a very light grey chert bed 2 feet 
thick which is one mass of silicified fossils; the majority of these are speci- 
mens of Euphemus carbonarius arenarius and Plagioglypta canna. The 
same association of species here noted in this chert bed is seen in the 
Permian ? of the region between Pipe Spring and Toroweap valley in 
northwestern Arizona. 1 Besides these species the following occur abundant- 
ly and usually only in the upper beds of the Rocky Mountain quartzite: 
Orbiculoidea arenaria, Productus semireticulatus, Paraphorhynehus obscurum, 
Bakewellia parva , Myalina wyomingensis , and Deltopecten occidental is 
latiformis. 
* Shimer, H, W., ‘Tarmo-Triaesic of Northwestern Arisona,” G.S.A. Bull. 30, pp. 480-483. 
