[ELLS & BARLOW] PROPOSED OTTAWA CANAL 185 
attitude with regard to the overlying clastics may, and doubtless has 
been, maintained since its original formation. In the country imme- 
diately adjoining the Mattawa River, and in the eastern part of Lake 
Nipissing, the gneiss is usually very distinctly foliated, although in many 
cases large areas are characterized by the presence of the more massive 
and granitoid varieties, in which cases the foliation is often more or less 
obscure and occasionally absent altogether. The dip is generally to the 
south at a high angle; but near the outlet of the French River from Lake 
Nipissing, and for a considerable distance down the river, the gneiss is 
either horizontal or inclined at a very low angle to the south. As Lake 
Huron is approached, however, the gneiss is again tilted up, and displays 
a remarkably uniform dip in a southeasterly direction at a comparatively 
high angle. On a map shortly to be issued by the Geological Survey (as 
well as on some others previously issued) the attempt has been made to 
correlate the many apparently conflicting strikes obtained through this 
district, and to show by means of certain lines the curious curving and 
twisting affected by this gneiss. 
A large number of dykes cut these gneisses, but no petrographical 
examination has yet been made of their contents. A rather remarkable 
and unusual dyke, about ten feet wide, was noticed cutting across the 
strike of the foliation of the gneiss on the most southerly of the Manitou 
Islands. The rocks comprising the dyke resemble in a striking manner 
the alnüite rock described by Dr. F. D. Adams as occurring at Ste. Anne’s. 
on the Island of Montreal. Dykes of fine-grained felsite and veins of 
pegmatite are, as usual, tolerably abundant. 
