110 COMMISSION OP CONSERVATION 



pitted and scored. In these depressions He the lakes, which are so 

 abundant in the area, or in somfe cases swamps, and the streams and 

 rivers which connect and drain them. The accentuation of the country 

 is, however, very low, and it is very seldom indeed in any portion of the 

 area that the lulls whose summits represent the plain rise as much as 

 250 feet above the waters of the lake or river at their foot. In by far 

 the greater number of cases the difference in level is much less than 

 this. The greatest difference in level of any two points on the map, so 

 far as known at present, is 639 feet, the highest point being that north 

 of Majniooth, referred to above, and the lowest being the surface of 

 lake Kamaniskeg, lot 12, concession xix, in the township of Raglan. 

 If the depth of the waters of this lake were added to the figure given 

 above, the maximum difference in level to be found in the area covered 

 by the map would probably be obtained. 



At some points in the area, as has been mentioned, isolated hills, 

 or small groups of hills, forming notable features in the landscape of 

 the surrounding district, rise above the general surface of the plain. 

 These, as has been mentioned, are usudly composed of some more 

 resistant rock, and survive on accoimt of the greater resistance which 

 they offer to the action of the forces of denudation. One of these 

 already mentioned — Greens mountain — on lots 15 and 16, concession i 

 of Glamorgan, rises 1,466 feet above sea-level, or 253 feet above the 

 level of the surface of the surrounding plain, and is composed of a mas- 

 sive gabbro. Another, made up of syenite, is known as the Blue moim- 

 tain, and is situated in the central part of the township of Methuen. 

 It is, at its highest part, 300 feet above the surface of I^shabog lake, 

 which lies immediately south of it, or about 1,100 feet above sea-level. 

 Its height above the plain, in a shallow depression of which the lake 

 lies, would thus be somewhat greater than that of Greens moimtain, 

 although its height above sea-level is considerably less. 



Along the southern margin of the map area also, conspicuous hUls 

 are formed by the isolated outliers of the horizontal Palaeozoic strata 

 of the great plain of central Canada, which bounds the Archtean cotmtry 

 on the south. These Paleozoic strata formerly completely covered 

 this Archaean coimtry, along its southern portion at least, the surface 

 of what we may term the Archaean plain being seen to pass beneath 

 them. Now that the strata in question have been almost entirely 

 stripped off, and the underlying Archaean (or pre-Palffiozoic) plain is 

 once more laid bare, these surviving remnants of the Palaeozoic stand 

 up from the surrounding Archaean country as steep-faced hills, com- 

 posed of horizontally bedded limestones, and which can be seen for long 

 distances. 



The plain is almost everywhere more or less mantled by drift, the 

 ice of the glacial period being the latest agent of erosion. The thick- 

 ness of this drift varies considerably in different places. Over the 

 greater portion of the area it is comparatively thin, so that, while it 

 forms the soil of the country, the underlying rock, in the form of smooth 

 roches moutonnies, protrudes through it at frequent intervals, giving 

 ample opportunity for a study of the petrographical character, and the 

 structure of the rocks beneath. In some districts, however, the drift 

 is heavier, and forms an almost continuous covering, no exposures 



