ANCIENT STRAIT AT NIPISSING. 62l 



the Saint Lawrence at Montreal." The latter I found b}^ Doctor Spencer's table of 

 altitudes in Canada to be 12 feet above high tide in lake Saint Peter, or 23 feet 

 above mean tide level, making the station at North bay 658 feet above the sea. 

 The level of lake Nipissing is a trifle less than 15 feet below the station, but accord- 

 ing to the Canadian Geological Survey " lake Nipissing is 065 feet above sealevel. 

 By the same authority it is stated that levels were run from Trout lake to lake 

 Nipissing, showing the former to be 25 feet above the latter, and that the height 

 of land on the portage from Trout lake to the Eiviere a la Vase, which flows into 

 lake Nipissing, is 212- feet above Trout lake ; but I have used the Canadian Pacific 

 railway levels, which would make lake Nii3issing about 20 feet lower. I am in. 

 debted to Mr John Bourke of North hsiy for an excellent map of Widdifield town- 

 ship, which contains all the places referred to near North bay. The location of 

 the beaches described will be found on plate 20. 



Bk ACHES. 



THE XIPISSIXG BEACH. 



At Mr Jessup's house, on the north side of the west end of Trout lake, a little 

 more than four miles east-northeast from North bay, this shoreline may be seen 

 as a delta-terrace, filling a recess in the hill where a small stream enters. Its front 

 edge is about 50 feet above Trout lake, and its back 10 to 15 feet higher. At this 

 place it is composed mainly of gravel, comparatively fine and free from bowlders. 

 From this point westward it continues with the same strong character past Chip- 

 I)ewa creek and tlie Temiscamang road, which is as far as the ground was seen. At 

 the foot of the hill west of Jessups the terrace becomes a narrow shelf close to the 

 lake, and is composed of a mass of well rounded bowlders, many of them more than 

 a foot in diameter. For more than half a mile it retains this form, but beyond that 

 it gradually loses its steepness in front and becomes wider and finer in composition. 

 Toward Chippewa creek it widens still more und in a few places low beach ridges 

 of gravel were noticed along its front. 



About a mile north of North bay the flats end abruptly against the face of a ter- 

 race of bowldery drift. This terrace is a small i)lateaa which projects southward 

 about a mile from the foot of a high hill. It is probably of glacial origin, but it 

 has been largely modified l)y the later action of waves, and possibly also to some 

 extent by the flowing water of tlie abandoned outlet river. Its southward front 

 has been eroded away in comparatively recent time, for it is still a steep, fresh 

 blutr. Its eastern slope is more gradual and is covered by a series of well formed 

 beach ridges, which may be seen to good advantage from the Temiscamang road 

 about a quarter of a mile north of the water-tower. The fork of the road north of 

 the tower is on the crest of the plateau, and also upon a gravel beach ridge which 

 extends about half a mile northwest from that point. The altitude of this ridge is 

 about 85 feet above the station, and the Temiscamang road follows it from the fork. 

 The beach at the fork is a little higher than the terrace at Jessups, but not more 

 than the proper difference between a beach and a terrace. 



I did not see the slopes at corresponding-levels south of the old channel, except 

 what may be seen from the train near Callendar. At that place there is appar- 



* As quoted in the " Report of Commission on Forest Preservation and National Park," etcetera, 

 Toronto, 1893, p. 32. 



LXXXVI— Bull. Geol. Soc. Am., Vol. 5, 1893. 



