670 REVIEWS 
of the coals and their relatively high percentage of ash is probably a 
result from this mode of origin as is also the absence of fire clays beneath 
them. The available reserves of the field are estimated at three and 
one-half billion tons. 
E. S. BASTIN 
Summary Report, Canadian Geological Survey. Ottawa, 10109. 
Pari C. Alberta-Saskaichewan Region. Pp. 52. 
1. “Cretaceous, Lower Smoky River, Alberta.” By F. H. 
McLeEarn. 
2. “Geology of the Swan Hills in Lesser Slave Lake District, 
Alberta.’’? By JoHn A. ALLEN. 
3. “Northern Part of Crowsnest Coal Field, Alberta.” By 
BRUCE ROSE. 
4. “‘Gasoline in Natural Gas. Experiments on Alberta Gas.” 
By D. B. Dow tne. 
5. “Surface Deposits of Southeastern Saskatchewan.” By 
, J. STANSFIELD. 
The annual Summary Report of the Canadian Geological Survey for 
1917 and since is issued in parts and each part is designated by a letter 
of the alphabet. Before 1917 the whole annual Summary was bound 
in one large volume. 
1. The Cretaceous begins with the Lower Cretaceous and extends 
into the Montana group of the Upper. Marine and non-marine forma- 
tions alternate and the total thickness represented is about 4,470 it. 
The Dakota sandstone cannot be recognized in its normal subaerial 
development. The beds dip to the south from 12 to 60 ft. per mile 
and represent the north limb of a very broad, shallow syncline. The 
structure is not favorable for oil. 
2. The Swan Hills lie south of Lesser Slave Lake, have a maximum 
elevation of 4,320 ft. above sea-level, and represent remnants of a once 
more extensive, maturely dissected upland. The Cretaceous is repre- 
sented by the Montana group. The basal member is marine, and the 
upper two members, the Sawbridge and Edmonton, are of fresh-water 
origin. ‘The early Tertiary is represented by the Paskapoo formation 
but there is no marked unconformity between the Upper Cretaceous 
and the Tertiary. 
3. Formations ranging from Devono-Carboniferous to Upper 
Cretaceous, probably Tertiary, in age, are described. Coal seams of 
