136 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



distribution of the carbonate-bearing strata is rather general but they are 

 probably most numerous in the lower part of the formation. Pure limestone 

 or dolomite was nowhere found. 



Sun-cracks are extremely abundant throughout the formation and ripple- 

 marks are not uncommon. No oasts of salt-crystals were observed in any 

 section. The very different looking cuboidal casts of weathered-out pyrites 

 occur at several horizons. 



The specific gravity of eight typical specimens, ranged from 2-567 for the 

 shales to 2-735 for the dolomitic quartzites. The average of all is 2-676, which 

 is not far from the average for the whole formation. 



The stratigraphic relation of this formation to the Kitchener suggests at 

 once that it may be the equivalent of the Gateway, Phillips, and Roosville 

 formations of the Galton range. The writer believes such to be the fact. 

 There is a close lithological similarity, especially between the Gateway and 

 Moyie formations, not only in composition and general habit, including thin- 

 bedding and colours, but as well in the persistence of shallow-water features 

 through the beds. The apparent absence of salt-crystal casts, so characteristic 

 of the Gateway and Kintla formations, does not appear to be of vital signifi- 

 cation in the correlation, for obviously the conditions for the development of 

 a supersaturated brine would not extend over an unlimited area of contempor- 

 aneous sedimentation. The deposition of the Moyie sediments may well have 

 taken place in open-sea water. Some of the calcareo-magnesian quartzites 

 and argillites have close resemblance to the impure Sheppard dolomite, the 

 equivalent, in the Clarke and Lewis range?, of the lower Gateway formation. 



With longer study of the known outcrops of the Moyie formation and, 

 above all, with the discovery of more favourable exposures, it may be possible 

 in the future to subdivide this group of beds; at present, it seems best to 

 recognize only the one inclusive formation name for the sediments overlying 

 the Kitchener in the Moyie and Yahk ranges. 



Gateway Formation in the McGillivray Range. 



In the McGillivray range the conditions for immediate correlation with 

 the Galton series are more favourable. The peaks of the highest ridges in the 

 Boundary belt are almost all composed of the Purcell Lava formation, which, 

 as we shall see, is the most perfect horizon-marker in the Rocky Mountain 

 sections. At the summit of the McGillivray range this lava formation has 

 been warped into a broken, north-pitching syncline. Considerably more than a 

 thousand feet of thin-bedded, sun-cracked and much ripple-marked strata 

 conformably overlie the lava. 



The base of this group is formed of beds unquestionably equivalent to those 

 in the lowest Gateway, while the main mass is lithologically transitional 

 between the upper 1,850 feet of the Gateway strata and the more heterogeneous 

 Moyie strata. The closer affinities of these strata at the summit of the range 

 are distinctly with the Gateway formation and its colour has accordingly been 



