186 GEOLOGICAL SURVEY OF THE TERRITORIES. 



geographer as well as to the geologist. Although but little would be 

 expected from the volcanic area to occupy the geologist's attention and 

 satisfy his desire for new and interesting features, it was still found to 

 possess so many unique characters that it could but be regretted that 

 not more time dare be given to the study of detail structure and com- 

 position. Many points of importance must have escaped notice, because 

 the rugged character of the country is such that much may be bidden 

 to the eye of one who cannot command over an almost unlimited amount 

 of time. It only remains to be hoped that subsequent explorations, 

 carried out on a larger scale, may find and make known the numerous 

 interesting localities that are as yet undiscovered. Large as the con- 

 tinuous volcanic area is, extending eastward into a portion of the work 

 completed in 1873, its boundaries have not yet been reached. During 

 the summer of 1875, the same party will have an opportunity of explor- 

 ing the adjacent country to the south, and no doubt important facts 

 will be observed during the survey. 



In intimate relation with the geognostic features of the district 

 surveyed, we find the distribution of the drainage. So marked is the 

 difference appearing in the plotted sheets, that any one familiar with the 

 general character of the country, might deduce from the horizontal pro- 

 jection of drainage the approximate outlines of geological formations. 

 This would not be possible, were there extant there a large number of 

 such formations, consisting each of numerous members, but as this is 

 not the case, the deciding characteristics for each geognostic group are 

 well defined. 



