226 O. If. Daicson — Geology of British Columbia. 



crosses the 49th parallel near the 121st meridian, southward to the 

 Blue Mountains of Oregon, south-westward to Mount Shasta, and 

 from this, according to Whitney, still further southward along the 

 western slope of the Sierra Nevada. To the north it appears nearly 

 to follow the present north-eastern line of the Coast Range to the 

 52nd parallel, when it turns north-eastward, passing completely 

 across the line of the Gold Eange, and by straits and openings 

 through the Rocky Mountains on the 55th parallel, connecting this 

 with the great Cretaceous Mediterranean Sea of the interior of the 

 continent. In the southern part of British Columbia it would appear 

 that the Rocky Mountains proper were not at this time elevated, but 

 that the Cretaceous Mediterranean washed the eastern shore of the 

 Gold Range. In the Peace River region, however, just mentioned, 

 there is ample proof that the Rocky Mountains formed even at this 

 time a more or less continuous shore-line or series of islands, around 

 which the Cretaceous beds were deposited. 



The existence of a great thickness of rocks of volcanic origin in 

 the Cretaceous of several parts of the Province has already been 

 alluded to. Their resemblance to those described as occurring in 

 the Cordillera region in Chile, by Darwin, has been pointed out by 

 the writer in a former communication to the Geological Magazine.^ 



The Cretaceous closed with another period of folding, in which 

 additional height was given to the Vancouver and Queen Charlotte 

 Island Ranges, the Coast Ranges were produced, as well as cor- 

 rugations doubtless caused still further eastward which cannot now 

 be separated from those of other periods. At this time, or shortly 

 after, the Rocky Mountains attained their full height and development. 



No trace of the earlier or Eocene Tertiary has been found in 

 British Columbia, and it is probable that the Province was through- 

 out at that time a land area. In the Miocene, the relative elevation 

 of sea and land was much as at present, but the great inland lake 

 formerly alhided to was in existence. This lake was doubtless the 

 northern continuation or homologue of that which has been called 

 the Pah-Ute Lake by Clarence King, and which lay east of the 

 Sierra Nevada on the 40th parallel. The rocks formed in it thus 

 represent the Truckee Miocene of King's section. 



The Miocene closed with extensive volcanic disturbances through- 

 out the country south-west of the Gold Range, and eventually by 

 still another epoch of corrugation and crumpling probably synchro- 

 nous with that which produced the Tertiary Coast Hills of California, 

 and which may have given to the northern part of the coast the 

 greater elevation, which it appears to have possessed during Plio- 

 cene times, when the wonderful system of fiords, by which it is now 

 dissected, were cut out. 



The most striking points brought out by the study of this region 

 are probably the following. First, the repeated corrugation, parallel 

 in the main to a single axis, which has occurred in the Cordillera 

 region. Second, the occurrence of great and wide-spread masses of 



1 Geol. Mag. 1877, p. 314. The rocks elsewhere described were at the time the 

 article in question was wiitten supposed to be Jurassic. 



