BT.JOHS.] TETON EANGE. 419 



melting of the snow-drifts, must present many wild, picturesque cas- 

 cades. 



The east face of Station XXXVII ridge drops down in precipitous 

 slopes over the Carboniferous beds to the buff heavy-bedded magnesian 

 limestone of the Niagara, which here occurs in characteristic escarp- 

 ments, its foot often buried in debris. Beneath the latter successively 

 appear ledges of the dark thin-bedded Quebec limestone, underlaid by 

 rusty yellow and red deposits pertaining to the quartzite horizon, which 

 mount higher and higher as they advance towards the summit of the 

 range, where they crown massive Archaean heights with low parapets and 

 debris caps. The view from this point is very grand and instructive, 

 opening as it does something like adequate conception of the slow-operat- 

 ing forces which have reduced the great uplift to its present diverse 

 aspects. To the north we always overlooked a field in which the Archaean 

 rocks form a prominent element ; but in this quarter we are able to form 

 a more just conception of the agencies by which those more finished re- 

 sults were attained, and a measure of the progress of these forces in the 

 degradation of the immense superficial covering of sedimentary rocks 

 which originally roofed the whole range alike. While to the north of 

 West Teton Creek the crystalline rocks cover broad areas of the crest and 

 flanks of the range, where not only the mantle of sedimentary deposits 

 has been swept away to the last vestige, but the crystalline core has been 

 deeply eaten away ; here the granites outcrop in circumscribed basin- 

 areas, which retain almost the original contour of the surface upon which 

 the once continuous sediinentaries rested, while the latter, indeed, occur 

 everywhere; here in isolated islands, there in gigantic outlying masses 

 which hitch on to the great escarpment of the western foreland, by a 

 system of rugged connecting ridges whose distraction is hardly half con- 

 summated. There can be no doubt that the northern portion of the range 

 has been subjected to much greater denudation than the southern portion ; 

 but whether this indicates the greater time i>eriod during which these 

 forces have operated in the one quarter, or a less violent manifestation 

 of their action in the other, we shall endeavor presently to determine. 



The maximum elevation of the range probably culminated in the 

 vicinity of Mount Moran. It is reasonable to suppose that in this part 

 of the uplift the more fragmentary sedimentary covering was subjected 

 to greatest tension and consequent fracturing, by which these rocks 

 were here broken up, yielding more readily to the denuding agencies 

 than would be the case in less disturbed and lower portions of the range. 

 Hence, it is apparent that the area of greatest denudation corresponds 

 to that of greatest elevation ; and that, if the degrading agencies con- 

 cerned in the work of demolition have operated the same period in all 

 parts of the range, their work progressed with greater rapidity in those 

 portions where the rocks were most fissured and accessible to the ele- 

 ments combined in their destruction and transportation to the lowlands. 

 It is, to say the least, premature, in the present state of knowledge, to 

 discuss the forms in which the denuding forces were embodied which 

 carved mountains out of the sedimentary strata and planed down the 

 granitic nucleus. To what extent ice, in the form of glaciers, has acted 

 in this work we have only a few and far too insufficient data upon which 

 to build more than a conjecture, while, on the other hand, the ordinary 

 atmospheric effects of freezing and thawing, and water erosion and the 

 work of streams, are visible on every hand, the same to-day as in ages 

 past. There can be little doubt that special research in these mountains 

 will yet bring to light abundance of glacial phenomena; but whether to 

 this source alone are to be attributed the origin of the wonderfully diverse 



