18 'Wisconsin Academy of Sciences, Arts, and Letters. 
the direction N. 12° W., whose 14 observations should perhaps be 
added to the 139 directed N. 10 '' W., no other direction is repre¬ 
sented by more than six measurements. 
The fracture system of which these are the more prominent 
series has controlled in an important way the topography of the 
region, as has been described in the paper referred to. 
The larger basin of the near lying Lake Ontario has been 
shown by Wilson 1 to have its lines of drainage determined by 
fracture planes, though no indication is afforded of the cardinal 
directions characteristic of the system. This author says: 2 
“The direction of the master joint fractures is intimately asso¬ 
ciated with the trend of all the master valleys, though the 
modern post-Glacial channels are independent of them. . . 
These master joints with other associated valleys and the parallel 
system of valleys of similar trend on the adjacent Archean areas 
are probably associated with an extensive system of faults of 
pre-Ordovician date.” 
This province like that surrounding the Ausable chasm near 
Lake Champlain should afford a most promising field for the 
observation of cardinal directions within fracture systems. 
The French River District of Ontario .—Bell has called atten¬ 
tion to the marked orientation of the inlets and streams within 
the French River district of Ontario, 3 and has ascribed this ori¬ 
entation to the control by fissures, joints, and dislocations. The 
directions are strongly marked in the district and trend E-W or 
very nearly so, and approximately NW-SE, NE-SW. Bell 
says: 
“The effects of cleavage and bedding, fissures and joints, lock- 
crushing, dislocations, intrusive dikes, etc., on the production of 
geographical features are here so well marked as to make it 
worth calling attention to some points in connection with this 
subject. In any part of the district we may select, it will be 
found that the joints, fissures, and dislocations, generally run in 
two sets intersecting each other at large angles, but those of 
1 Wilson, A. W. G., Trent River system and St. Lawrence outlet. 
Bull. Geol. Soc. Am., Vol. 15, pp. 211-242. Pis. 5-10. 
2 Bell, Robert. Report on the geology of the French River district, 
Ontario. Geol. Surv. Can., Ann. Rept, N. S., Yol ix, 1896, pp. 20-1 to 
21 - 1 . 
