PRE-CAMBRIAN NORTH AMERICAN LITERATURE 363 
I. Quartzite Division. 
(a) Heavily bedded blue quartzites, with slightly plumbaginous part- 
ings, alternating with numerous but much thinner beds of gray 
argillite. In metamorphic areas the quartzites become more mica- 
ceous, assuming the aspect of fine-grained gneisses, while the finer 
beds become glistening mica-schists. 
(4) Greenish-gray sandstones or quartzites, less massive than in (a) 
and alternating with slates which are arenaceous below, but become 
gradually more argillaceous above. 
2. Slate Division. 
(za) Greenish-gray slates, becoming bluish or light gray, and passing 
into purple slates, or becoming clouded or zoned with shades of 
green, purple, blue, buff or pale yellow, often producing a conspicu- 
ous ribbanding of the beds. The occurrence of light yellowish- 
green seams is a characteristic feature of the purple slates. 
(6) Bluish-gray and blue slates, with lighter gray seams or bands, and 
including in places an upper zone of purple slates. 
(c) Black, with some blue or gray slates, often highly pyritiferous. In 
metamorphic regions the green slates are represented by chloritic 
and hornblendic schists (or locally by conglomerates with a mica- 
ceous or hornblendic base); the slaty beds by micaceous, garnetif- 
erous, and andalusitic schists. 
Above the Cambrian rocks are those belonging to the Devonian system. 
There are several important areas of granite, as follows: Those of South 
Mountains, Blue Mountains, Tusket Wedge, the Barrington area, Kelvin 
area, and Port Mouton area. These are intrusive within the Cambrian, and 
in places they clearly penetrate and alter the fossiliferous Devonian rocks. 
Comments.—The rocks here referred to the Cambrian are the so-called 
gold-bearing slates. This great series I have regarded as probably equivalent 
to, and belonging in the same geological province with, slates of Newfound- 
land unconformably underlying the Cambrian. I have therefore doubtfully 
referred the Nova Scotia slates to the Algonkian. No paleontological evi- 
dence is given in this paper which decides between the Cambrian and Algon- 
kian periods. 
Bonney* states that the Eozoon of Céte St. Pierre is either a record of an 
organism, or a very peculiar and exceptional condition of a pyroxene-marble 
of Laurentian age, which is not a result of contact metamorphjsm in the 
ordinary sense of the term. 
by L. W. BaiLey, Geol. Sur. of Can., Ann. Rep. for 1892-3 (new series), Report Q. 
1895, pp. 21. With map. 
*The Mode of Occurrence of Eozoon Canadense at Céte St. Pierre, by T. G. 
BONNEY, Geol. Mag., new ser., Vol. II., 1895, pp. 292-299. 
