24 Geology of Mt. Stephen — McConuell. 
calcareous shales. In some places the dolomites and limestones 
are replaced in part, or altogether, by a great series of greenish 
calc-schists and greenish and reddish shales and slates. The 
Castle Mountain group is found at intervals across the whole 
width of the range, but it is otherwise with the succeeding 
formations. In the eastern part the section is very imperfect, 
as both the Silurians, as well as all the formations between the 
Carboniferous and the Middle Cretaceous, so far as known, are 
wanting. In this section the Castle Mountain group is over- 
laid by the intermediate limestone of Devonian age, and this 
by the Banff limestone of Devono-Carboniferous age, above which 
and forming the top of the section come the shales, quartzites 
and conglomerates of the Cretaceous. In the wertern part of 
the range the Castle Mountain group graduates upwards into a 
series of black shales holding graptolites which professor Lap- 
worth has assigned to the Utica-Trenton fauna, above which 
comes a limestone holding Halysites catenulatus. This suc- 
cession is expressed in the following section: 
Zone of Halysites catenulatus Ualysites beds. 
Zone of Graptolites (Utica-Trenton) Graptolitic shales. 
Zone of Asaphus ] 
[■ Castle Mountain group. 
Fauna described by Dr. Rominger, ) 
Zone of Paradoxides ] 
[• Bow Kiver group. 
Zone of Olenellus ) 
Total thickness 23,000 feet. 
In Mt. Stephen and its eastern neighbor, Cathedral mountain, 
only the two lower formations are present. In the latter moun- 
tain the beds of the Bow River group were composed princi- 
pally of quartzites, with some slates and schists, alternating 
above with the limestones of the Castle Mountain group and have 
been carried up by an anticlinal to a hight of over 3,000 feet, and 
are well exposed all along the lower slopes of the mountain. The 
upper cliff-part of the mountain shows the limestones, shales and 
dolomites of the Castle Mountain group, to the steep weather- 
ing of which the peculiar configuration from which the moun- 
tain derives its name is due. The beds of the Bow River group 
can be traced westwards to Mt. Stephen, but here, although 
the easterly dip is sHll maintained, they suddenly disappear, 
and the whole mountain from base to summit is composed of 
