134 MORLEY E. WILSON 
With regard to the characteristics of these sediments which 
have a climatic significance, it may be observed from the features 
mentioned in the previous paragraph, that these, in general, point 
to humid rather than to arid or semiarid conditions of deposition. 
Furthermore, bowlders occur in places in the midst’ of fine grained, 
stratified greywacke and argillite, a condition which seems to 
necessitate the presence of floating ice. From this, it may be 
inferred that the climate of this period was not only humid but cold. 
4. Aeolian deposition.—Since the greater part of the finer 
grained material comprising the Cobalt series is uniformly bedded, 
it is evident that these are subaqueous deposits. Moreover it 
was pointed out in the previous paragraph that the climate, at the 
time these materials were laid down, was probably cold and humid. 
Consequently it may be inferred that aeolian action was never a 
depositional factor and probably played little or no part in the 
formation of the series. 
5. Fluviatile deposition.—The general great heterogeneity of 
the conglomerate of the Cobalt series, the great variability in the 
matrix, in the size of the pebbles, and bowlders, and in the rock types 
represented in the conglomerate, the varying degree of abrasion 
to which the pebbles and bowlders of the conglomerates have been 
subjected, the presence of cross-bedding in places are all characteris- 
tics commonly pertaining to sediments of a fluviatile origin which 
have been deposited not far from the source of supply. The 
conglomerates of the Cobalt series have therefore the essential 
characteristics of fluviatile deposits.? 
Notwithstanding, however, the apparent similarity of the con- 
glomerates of the Cobalt series to river deposits, there are some 
features associated with these which are inconsistent with a flu- 
viatile origin. A considerable part of the bowlders contained in 
the conglomerate, in places, are 2, 3, or even 8 feet in diameter? 
and are commonly many miles from the nearest occurrence of similar 
rocks in the older complex. Moreover, the surface upon which 
tA. B. Coleman, Jour. Geol., XIV (1908), 153. 
2C. R. Mansfield, Jour. Geol., XV (1907), 550-55. 
3 Jour. Geol., XVI (1908), 151; “‘Prel. Rep. Gowganda Min. Div.,” Geol. Surv., 
Dept. of Mines, Can. (1909), p. 27. 
