550 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



Rossland and Midway mountains; the Rossland latites and monzonite; and the 

 Bayonne granodiorite batholith, and the satellitic stocks of biotite granite to the 

 southwest. 



Correlation among Formations at the Forty-ninth Parallel. 



Using these various principles the writer has constructed the following 

 table (XXXIV) of correlation for the formations traversed between the 

 Purcell Trench at Porthill and the Gulf of Georgia. It is seen that the argu- 

 ment for the general correlation is a dove-tailed combination which is stronger 

 than would be a classification founded on a much smaller number of principles. 

 The writer believes it to be considerably stronger than would at first sight seem 

 possible in view of the very few fossiliferous horizons actually discovered on the 

 Forty-ninth Parallel. Much of the correlation would be impossible without the 

 aid of earlier work done in the regions to north and south of the Boundary line ; 

 the cumulative evidence of such results together with the many facts detailed 

 in the preceding chapters, has prompted the constructive scheme shown in this 

 table. 



In this and the following correlation tables the formations in any compart- 

 ment are listed in order of age, where possible, but in many cases this could 

 not be accomplished. 



A brief list of the more doubtful references stated in the table will be of 

 convenience, although a fuller account of the problem in each case must be 

 sought in the descriptions of the preceding chapters. 



Further information is needed concerning the paleontology of the sediments 

 interbedded with the Beaver Mountain and Rossland volcanic groups. Direct 

 paleontological evidence is greatly needed for the correlation of the Pend 

 D'Oreille group as mapped east of the Columbia river, as also for the correlation 

 of the Attwood, Anarchist, and Hozomeen series. The lower beds of the 

 Chilliwack series are as yet quite unf ossiliferous and, on account of the relatively 

 low degree of metamorphism of the Paleozoics in the region west of the Chilli- 

 wack batholith, there is reason to hope that fossils may be found in that 

 interesting part of the series. The apparently unconformable position of the 

 Tamihy series upon the Chilliwack (Upper Carboniferous) beds needs to be 

 confirmed by further study; the relation of the Tamihy series to the Cultus 

 (Triassic) formation should, if possible, be determined. Among the igneous 

 bodies, greatest doubts are felt as to the dates of the Rykert, Trail, Cascade, 

 Osoyoos, and Remmel batholiths, the Rossland and Beaver Mountain volcanics, 

 and the Skagit volcanic group. All of these bodies are specially mentioned on 

 account of their quantitative importance as well as on account of their general 

 relations to the historical geology of the Cordillera. Full of errors as the table 

 may be, the writer is impelled to publish it with the hope that it may be of 

 some aid to future workers in the geology of the region. Upon them will 



