8 
Burling concludes that “The correlation of the Burton formation with 
the AlberteUa fauna is based largely upon the presence in the former of an 
Albertella , a genus which, according to our present information, is confined 
in the Cordilleran region to this one horizon. The weight of evidence so 
largely opposed the Lower Cambrian age of these formations and corrobor- 
ates their reference to the overlying division of the Cambrian that the 
Burton formation is referred with some degree of certainty to the Middle 
Cambrian.” 
“It is hard to resist the impression, however, that the clastic portion 
of the Burton formation may represent the Lower Cambrian, and while 
the few species occurring in these lower layers are either unrecognizable 
or referable to types hitherto unknown, the suggested division of the 
Burton formation will not invalidate its future division into shale and 
sandstone members.” 
“The Burton formation is, therefore, interpreted as a more or less 
heterogeneous formational unit unconformably overlying the Precambrian, 
and easily separable into upper and lower members if such a division 
should be warranted by future. work upon the faunas of its basal portion.” 
In 1916 Burling 1 located the Albertella fauna in a shale member of 
the Middle Cambrian Cathedral limestone 375 feet above its base. This 
definitely places the upper part of the Burton formation in the Middle 
Cambrian. 
Walcott in 1921 in a personal communication correlates the upper 
part of the Burton formation with the Ptarmigan formation 2 , which carries 
the Middle Cambrian fauna (lower) including the Albertella fauna and 
the lower part of the Burton formation with the Mount Whyte formation 
of Lower Cambrian age. The section at Elko, therefore, may be repre- 
sented according to Walcott as follows: 
The Elko formation is correlated with the Cathedral formation of 
Middle Cambrian age. 
Elko Feet 
Middle Cambrian /Elko limestone 
\Burton formation, upper part 60 
Lower Cambrian Burton formation, lower part 18 
Unconformity 
Precambrian Roosville formation 
(Gal ton series) Phillips formation 
Gateway formation 
Unconformity at the Base of the Burton 3 . Although no structural 
features emphasize the presence of an unconformity at the base of the 
Burton, yet from other evidence such an unconformity is believed to exist. 
(1) A marine Cambrian transgression is inferred in the deposition of 
the Burton formation since this inference is in harmony with other sections 
of the Rocky Mountain geosyncline. 
(2) The conglomerate at the base of the Burton is composed chiefly 
of hematitic material with pebble-like shape and minor quantities of pebble^ 
of quartzite and quartz in a hematitic cement. A concentric structure 
suggesting concretions characterizes some of the hematitic constituents of 
the conglomerate. All the hematitic pebble-shaped elements probably 
represent subsequent erosion and concentration of hematite deposits which 
1 Burling, L. D., Am. Jour. Sci., vol. 42, 1916, p. 469. 
a Walcott, C. D., Smithsonian Misc. Coll., vol. 67, No. 1, 1917, p. 1. 
* Schofield, S. J., Geol Surv., Can., Mus. Bull. No. 2, 1914. 
