402 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 16, 



coast, and extends as far as Lake La Pluie*. It always forms hum- 

 mocks, ledges, and low bosses, and sometimes overspreads many- 

 square miles with little change, particularly in the west, as far as the 

 extensive swamps will allow us to see. This granite is grey and pale 

 red, and the mica is black. It is coarsely granular, and only por- 

 phyritic when it forms a vein. Although through its course of 

 100 miles, from Monument Bay to River Neketchawonan at the 

 N.E. end of Lake La Pluie, its mineral composition varies from place 

 to place, yet it always returns to one particular type (that of Gravel 

 Point). 



In this district granite is always the lowest rock, and traverses all 

 the other rocks. It is frequently gneissoid. 



A distinct form of granite is met with on the east side of Lake 

 Kaminitic, about the mouth of the River Anagoyahme, but I only 

 saw a small quantity in situ. 



The metamorphic or stratified rocks, few in number, and altogether 

 different on the different sides of the anticlinal, are gneiss, mica-slate, 

 hornblendic, chloritic, and syenitic greenstone, and greenstone-con- 

 glomerate. They flank the granite, as we have before said, on both 

 sides, — those on its north side (greenstones principally) dipping 

 W.N.W. for the most part, but sometimes N.W. and N. ; sometimes 

 vertical, and, at Isle a la Crosse, with a S.E. dip; the last observation, 

 however, is perhaps inaccurate f . 



In Lake Kaminitic the E.N.E. and N.E. strike {normalX for the 

 countries on the immediate south) is very conspicuous in the syenitic 

 and conglomerate greenstones. 



But in Sandhill Lake, on the south side of the granite, the stratified 

 rocks dip, with small occasional deviations, to the S.S.W., — a direc- 

 tion resulting from the form and position of the intrusive rock. 



At the S.E. end of Sandhill Lake, regularity of stratification is 

 lost for 300 square miles, as will be afterwards shown. 



These observations on dip and direction were made with the com- 

 pass planted on the rock, and were more numerous than set down on 

 the Map, PI. XXII. They nearly coincide with the only two notices 

 of strike, &c. in this lake given by Professor Keating §, Geologist to 

 the Expedition to the River St. Peter's under Col. Long. 



* Not included in the accompanying Map. See Map of Canada, Quart. Journ. 

 Geol. Soc. vol. vii. pi. 14. 



t The magnetic variation in this lake is 5° to 7° E. 



X In the neighhouring Lake La Pluie, which is 300 miles round, and is based on 

 gneiss, mica-slate, ohlorite-slate, &c., out of 120 observations taken in all parts of 

 it, only fourteen deviated considerably from a W.S.W. or W.N.W. strike, and al- 

 most all these occur in chlorite-slate. The W S.W. strike is by far the most 

 common strike in Lake La Pluie, as well as along the 220 miles of lake and morass 

 south-eastwards to Grand Portage, Lake Superior. If we add to this similar 

 statements respecting Lake Superior, made by MM. Foster and Whitney, and by 

 Dr. Dale Owen for 150 to 200 miles, south of Lake Superior, in the State of 

 Wisconsin, we shall see that the general trend (with local variations) of all the 

 metamorphic rocks from the River Winnepeg for 700 miles south is W.S.W., — a 

 fact of great interest, as indicative of an enormous breadth of uplift. 



§ That near Rat Portage coincides exactly. 



