CORRELATION 265 



with the Upper Paleozoic beds of southeastern Alaska. The subdivision 

 made by Schrader and Spencer of the beds below this limestone finds but 

 little analogy in the older sediments of the region under discussion. 



The comparison of the Mesozoic beds of the two regions does not sug- 

 gest correlations. In the southern region the Mesozoic is represented, 

 as far as known, more especially by conglomerates and coarse fragmental 

 beds, while in the Copper River basin the rocks of this age are chiefly 

 limestones and black slates. The Kennicott series, however, in the Cop- 

 per river of Jura-Cretaceous age is made up of fragmental rocks similar 

 in character to the Mesozoic of southeastern Alaska. The Tertiary sedi- 

 ments of southeastern Alaska are chiefly Kenai, and this horizon has 

 been identified in many parts of Alaska. 



Dawson's last investigation* on the geology of this northern region is 

 a report on the Kamaloop district in southern British Columbia. 



This work was done in much more detail than any which preceded, 

 and the stratigraphic succession was definitely determined. f The Kam- 

 aloop region is too distant from the province under discussion to make 

 correlations possible. It is interesting to note that the Cambrian period 

 is represented by beds aggregating a thickness of 40,000 feet. It seems 

 probable that some of the Lower Paleozoic beds of southeastern Alaska 

 may eventually be found to be of Cambrian age. The absence of Silu- 

 rian and Devonian in the Kamaloop region is noteworthy in comparison 

 with the southeastern Alaskan section. Dawson finds definite evidence 

 of the existence of pre-Cambrian rocks in this southern district. 



In Queen Charlotte islands J Dawson grouped the Triassic and Car- 

 boniferous beds together, and states that these are unconformably over- 

 laid by Cretaceous rocks. After the deposition of Triassic, folding took 

 place, and it was probably during this period that the granites were in- 

 truded. From the descriptions of Dawson these Triassic and Carbonif- 

 erous rocks show a striking analogy to the metamorphic argillites which 

 lie adjacent to the Coast Range granites in southeastern Alaska. Dawson 

 finds a large amount of volcanic material in the southern part of Van- 

 couver island, which he believes to be Carboniferous. These volcanic 

 effusives seem to have the same stratigraphic position as some found in 

 southeastern Alaska which have been provisionally assigned to the 

 Mesozoic. 



* George M. Dawson : Report on the Area of the Kamaloops, map sheet, British Columbia. Geol 

 Survey of Canada, Ann. Rept., new series, vol. vii, 1894. 



* Dawson summarized the results of his twenty-five years of investigation of northwestern 

 America in a presidential address to the Geological Society of America. "Geological record of 

 the Rocky Mountain region in Canada." Bull. Geol. Soc. Am., vol. xii, 1900, pp. 57-92. 



X George M. Dawson: Report on the Queen Charlotte islands. Geol. Survey of Canada, 1880, 

 p. 45 B. 



