APPLICATION OF NAME "ALBERTAN" 565 



of Wisconsin age, and that the ''quartzite gravels" on the high-level tracts 

 in the region under discussion were prerGlacial in age. 26 



Following this the name "Albertan" has fallen into disuse by glacial 

 geologists. 27 



It now appears from further study of the "quartzite gravel" and asso- 

 ciated till deposits on the remnants of the high-level plains in the Glacier 

 Park region that there is conclusive evidence, regardless of what may be 

 thought of the deposits studied by Dawson and McConnell, that there was 

 one or more earlier extensions of the Eocky Mountain glaciers. If, there- 

 fore, the name "Albertan" is to be used at all, it seems as though it should 

 be applied to the drift on the remnants of the highest plain, the Black- 

 foot peneplain, as best preserved in the Browning, Montana, quadrangle. 

 It should also include drift of the Cordilleran Glacier, which may be 

 shown to be of the same age, though lying in valleys farther north, but 

 should not include the mountain drift composing the moraines near the 

 front of the Eockies in southwest Alberta, these latter moraines probably 

 being of Wisconsin 'age. This makes the name a little incongruous be- 

 cause the most distinctive, and what should be regarded as the type, de- 

 posits of this drift have, so far as known, but very small areal extent in 

 Alberta. There are, however, good exposures of a thickness of 100 feet 

 of this high-level glacial till on the northern part of the ridge, which ex- 

 tends 5 or 6 miles north of the International Boundary on the east side 

 of Belly Eiver, and this may be regarded as typical of the "Albertan" in 

 southern Alberta. A similar deposit may yet be found on the ridge east 

 of Waterton lakes and possibly one or two ridges farther north, which 

 were not overridden by the later ice, may carry some of this drift, al- 

 though this is doubtful. 



Thus applied it would be used in a sense not greatly different from that, 

 intended by Dawson as designating the stage at which occurred the ear- 

 liest known extension of the Cordilleran Glacier and the deposits formed 

 by this glacier at this early stage. Dawson used the expression 'maximum 

 of the Cordilleran Glacier," but it is not clear that the extension of the 

 ice onto the plain in the Browning and neighboring areas al this earliesl 

 stage was on the whole greater than that at the Wisconsin stage. The 

 deposits on the high levels extend farther out from the mountain front 

 than do those of the Saint Mary and Cutbank glaciers, but nof farther 

 than those of the Two Medicine piedmont glacier. 



On the whole, however, and after consultation with Dr. T. (\ Cham- 

 berliu on the subject, we arc inclined to think that continuance i^i' the use 



■•P. ff. Calhoun: U. B. Geological Survey, Professional Paper 60, 1006, pp. 19-52. 



™T. C. Chamboriin ;m<i R. f>. Salisbury: Geology, vol. :\. 1906, p. 884. 



