102 
of its fauna may have drifted in. It also marks some increase in fine sand 
deposition and on Castle river in its uppermost part an increase in thick- 
ness of its sandstone beds, of which there is an even gradation into the 
bottom of the Kootenay. It has the marks of a transitional member 
between the marine Fernie and the non-marine Kootenay. The marine 
elements in its fauna indicate the presence of a sea somewhere in southern 
Alberta, although the deposit itself may be largely marginal and brackish 
or even in part non-marine. It is possible that it may mark the first 
uplift of land to the west, i.e., the Selkirk range 1 , resulting in a silting up 
of the interior sea, completed by Kootenay time, when non-marine alluvial 
plain deposition supplanted marine conditions in southern Alberta. With 
this interpretation of the “passage beds” and the relation of the Kootenay 
to the Fernie it is necessary to harmonize the Barremian or middle Lower 
Cretaceous age of the Kootenay with the basal Upper Jurassic age of most 
of the Fernie formation at Blairmore. Several possibilities suggest them- 
selves. Granting continuous deposition without any hiatus and a Barre- 
mian age of the Kootenay the Fernie strata above the zone of C. munda 
including the Green bed, and the “passage beds” would represent most of 
Upper Jurassic time and all of pre-Barremian Cretaceous time; a part at 
least of the “passage beds” would then be of Lower Cretaceous age and as 
the “passage beds” record a coeval sea somewhere in southern Alberta, 
the existence of a Lower Cretaceous sea in southern Alberta could be 
inferred. If, however, the Kootenay were not as late Lower Cretaceous 
as Barremian or were Barremian and also Neocomian and extended low 
enough to include earliest Lower Cretaceous or even the very latest Upper 
Jurassic, the “passage beds” would be of Upper Jurassic age and, at Blair- 
more, would contain the last record of the interior Jurassic sea or seas. 
On the other hand there may be hiatuses in the section. Assuming an 
hiatus of considerable magnitude at the base of the “passage beds”, equal 
say to all of post-Callovian Upper Jurassic time, and a Barremian age of 
the Kootenay, the “passage beds” would be of pre-Barremian Lower 
Cretaceous age and a Lower Cretaceous sea somewhere in southern 
Alberta could be inferred. Other possibilities may suggest themselves. 
An hiatus between the “passage beds” and Kootenay is unlikely, however, 
and, as a Barremian age of the Kootenay and a Jurassic age of the “passage 
beds” demands such an hiatus, both correlations cannot likely be possible. 
Much seems to depend on the dating of the “passage beds” and it is to be 
hoped that diagnostic fossils will be found in them. It would be unwfise 
to venture a correlation of the “passage beds” with the Lower Ribboned 
sandstone of the vicinity of Banff 2 and other localities farther north, 
although some lithological resemblance and the similar stratigraphic posi- 
tion might invite it. The Lower Ribboned sandstone may have also the 
marks of a transitional member, however. 
It may be noted that Warren 3 has recently discussed the relation of 
the Kootenay and Lower Ribboned sandstone to the Fernie formation in 
the vicinity of Banff, Alberta, and has held that the Fernie “represents a 
marine transgressive overlap, and, therefore, the overlying Kootenay 
formation may vary considerably in age in different areas.” He suggests 
1 Schofield, S. J.: Geol, Surv., Canada, Mem. 117, p. 64 (1920). 
* Dowling, D. B.: Geol. Surv. , Canada, “Cascade Coal Basin”, p, 8 (1907). 
* Warren, P. S.: Trans. Roy. Soc., Canada, 3rd ser,, vol. 21, sec. IV, p. fiO (1927). 
