[Ami] GEOLOGY OF SOME CITIES IN EASTERN CANADA 127 
fectly continuous section, constitute features which form an unusually 
interesting study about St. John and its vicinity. 
Laurentian.—In the column of geological systems, beginning with 
the oldest or Laurentian, Dr. Matthew has assigned certain crystalline 
schists of Indiantown and Fairville, to this horizon. These form a part 
of the Portland group (lower) of the reports bearing upon the geolog 
whereas the upper part of this group he classifies as Grenvillian, consist- 
ing of clay slates, norites, limestones, quartzites, underlaid by mica 
schists. 
Huronian.—The Laurentian Archean rocks are succeeded upwards, 
as Dr. Matthew points out by rocks of doubtful Huronian age, consisting 
of ash-rocks, felsites, diabase, diorite, such as are met with at Carleton 
Heights and Loch Lomond Hills, all grouped under the designation 
“ Coldbrook group.” Both above and below this Coldbrook group, as 
well as between the Laurentian of Indiantown and the Grenvillian 
limestones, slates, etc., of Green Head, Douglas avenue, etc., a marked 
discordance of stratification occurs, which apparently indicate long 
lapses or intervals of time between them. 
Cambrian.—Above the Coldbrook group, and beneath the Cambrian 
or St. John group, Dr. Matthew describes and classifies certain purplish 
and green shales, purplish red sandstones and coarse red conglomerates, 
which are exposed on Caton’s Island, in King’s County and at Loch 
Lomond, St. John County, under the term “ Etcheminian.” 
Between this Etcheminian and the St. John group, the discordance 
of stratification is not as obvious as in the case of the preceding system 
with the Etcheminian. The fauna of the Etcheminian, however, is 
essentially a Cambrian fauna according to the writer. 
The Acadian, Johannian and Bretonian constitute the three divi- 
sions which Dr. Matthew has established in the St. John group. The 
strata which they represent are 1650 feet in thickness and consist of 
mudstones, with slaty cleavage, also sandstones and flags with con- 
glomerate. The uppermost or Bretonian division of the St. John 
group which is to be seen in the black graptolitic shales and sandstones 
of Navy Island and at the Falls on the St. John River, near the Suspen- 
sion bridge, are by him referred to the Lower Ordovician. Many 
of the species which occur here are eminently characteristic of the 
Levis division of the Quebec group, in the St. Lawrence Valley. These 
strata correspond to the Skiddaw and Arenig formations of England 
and Wales and to similar horizons in Scandinavia, France and elsewhere. 
It is from the Cambrian or lower and most important portion of 
the St. John group of rocks that Dr. Matthew has obtained material 
from which he described and illustrated the very extensive extinct fauna 
