PRE-CAMBRIAN OF SOUTHEASTERN B.C. 
83 
Roosville siliceous metargillite and a great number of milky 
white to glassy quartz grains in a calcareous cement. This grit 
contains the oldest fossils found in the Galton series. Succeeding 
this grit is about 4 feet of calcareous, greenish black shale which 
readily weathers to soft earth. It is brittle and breaks up 
into small rectangular shaped pieces. Above this shale comes 
10 feet of sandy limestone, in beds from 1 to 2 feet in thickness, 
broken by vertical joints. The weathering colour of this 
limestone is brown. Above the limestone comes about 60 feet 
of greenish black, calcareous shale containing numerous band* 5 of 
siliceous limestone. These interbands are especially rich in 
trilobite remains. 
Elko Formation. The Elko formation, called after the town of 
Elko on the Crowsnest branch of the Canadian Pacific railway, 
rests upon the Burton formation. The exact contact between 
these two formations was not exposed in the sections studied and 
no structural evidence of an unconformity was present, exposures 
on each side of the contact being very good. 
The lower 30 feeb of the Elko formation is composed of mas- 
sive, grey, siliceous limestone, weathering grey, containing 
indistinct coral-like forms. The limestone by gradual transition, 
passes into a massive cream coloured siliceous dolomite in massive 
beds averaging about 6 feet in thickness. 
The Jefferson Limestone. In the Rocky Mountain system, 
the Devonian limestone rests conformably upon the underlying 
lower Palaeozoic Elko formation, while in the Purcell range to 
the west, an apparent unconformity exists between the Devonian 
limestone and the Gateway formation. The staple rocks of the 
Devonian are a massive, dark grey limestone and dolomites 
weathering a whitish-grey colour. The following fossils were 
found in the Jefferson limestone and were identified by Dr. 
Kindle. 
Atrypa reticularis. 
Atrypa cf. missouriensis. 
Spirifer englemanni. 
Strophostylus sp. 
Stropheodonta demissa. 
Schizophoria n. sp. near s. striatula 
