Section IV, 1889. [ 97 1 Trans. Eoy. Soc. Canada. 



VIII. — Notes on /he Geoniiiplnj imd Oeoloyij of the Bi<j Bend of the Golinnliia. [Plate 

 XVIII.] By A. P. Coleman. 



(Communicated by Dr. G. M. Dawson, May 15, 1889 ) 



The River Columbia rises about eighty miles north of the boundary of the United 

 States, and, after flowing about two hundred miles in a north-westerly direction to the 

 " Big Bend," suddenly turns south, or a little east of south, toward the fjord-like Arrow 

 Lakes and the State of Washington. The great curve thus made encloses on three sides 

 the Selkirks, one of the most rugged parts of British Columbia. Maps of this part of the 

 Province appear to be so defective as to serve only as very general guides to the traveller, 

 who is indeed beset by many dithculties not found in most other regions. It is proposed 

 to give in this paper a brief account of some portions of the region visited by the w^riter ; 

 touching first on some points of geography and statigraphy, and ending with the results 

 of a microscopic examination of a number of rock specimens. 



I. — G-eoctRaphy and Stratigraphy. 



(1.) The Spillimichene Region. — About fifty miles from its source, the Columbia 

 is joined by an important tributary, the Spillimichene,' rising in the Selkirk Mountains. 

 This river has two main forks, one flowing out of a wild region to the west or south-west, 

 and a longer one rising twelve or fifteen miles south of the mouth of the Kicking Horse 

 (Wapta) and flowing thirty or forty miles nearly parallel to the Columbia, though in the 

 opposite direction. The southerly trend of this and other tributaries is sometimes con- 

 sidered proof that the Columbia, or at least its upper part, once flowed in the reverse 

 direction. It is certain that a slight lowering of the south-eastern end of the valley 

 would allow the lakes in which the Columbia rises to empty southwards into the 

 Kootenay. A careful study of the relative heights of the numerous " benches " (terraces) 

 along this part of the river would throw much light on the subject. 



Mountains, between the Spillimicliene and llie Columbia. — The two rivers are separated by 

 a small range of mountains, rising well above the tree line (0,000 to 7,000 feet) toward the 

 head of the main branch of the Spillimichene and gradually sinking to wooded hills at 

 its point of junction with the Columbia. From the higher summits a magnificent view 

 may be obtained of nearly the whole Spillimichene valley, as well as of more than one 

 hundred miles of the broad valley of the Columbia. Their front toward the latter river 

 is very steep, so that one looks down as on a map upon miles of the valley with the 

 winding river, numerous half-choked channels, and crescent-shaped lakes representing 

 abandoned portions of its bed. 



' This name is variously spelled. The form chosen is that used by Dr. G. M. Dawson in bis Mineral Wealth 

 of British Columbia. 



Sec. IV, 1889. 13. 



