Wilson — Glaciation of Orford and Sutton Mts., Quebec. 205 



noted and it is possible that others also occur along the crest of 

 the mountain. They seem to owe their origin primarily to a 

 system of joint fractures which loosened the blocks that once 

 occupied the hollows. The smooth, even, striated sides are to 

 be attributed to ice scouring. 



Many of these small gullies cross the summit of the ridge 

 and open out on each side over very steep cliffs. They con- 

 stitute, in fact, very perfectly developed hanging valleys, but 

 of a most unusual type in those instances where the hollow 

 goes completely across the summit ridge. 



St. Annan id Pinnacle. — At St. Armancl Pinnacle, on the 

 lower slopes of the mountain, the writer has observed smoothed 

 and striated surfaces on the bed rock. At the summit Mr. 

 Dresser has noted similar striae trending to the east of south. 

 A profile view of the peak from the west shows a gently 

 ascending slope on the north side and a well developed cliffed 

 face to the south — the latter presumably a plucked face. 



Summary and Conclusions. 



In conclusion it may be stated that not only in the depressions 

 in this area, but also on all the important summits of the dis- 

 trict, distinct and unmistakeable. evidence of glacial transgres- 

 sion have been found. The cumulative character of this evi- 

 dence has already been referred to, and one seems justified in 

 concluding, with Mi*. Dresser and Professor Hitchcock, that the 

 height to which the ice sheet reached in this portion of eastern 

 Canada is as yet an undetermined quantity. 

 Department of Geology, McGill University, Montreal. 



Am. Jour. Scl— Fourth Series, Vol. XXI, No. 123.— March, 1906. 

 15 



