430 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 53 



Feet 



4. Shales similar to those of No. 3, with purple and greenish 



bands 65 



5. Shales similar to those of No. 3, of a dark-purple color 590 



6. Massive-bedded conglomerate, with coarse sandstone matrix, 



pebbles of white quartz, gray and yellowish buff sandstone, 

 green siliceous shale, and rolled fragments of a reddish pur- 

 ple, jaspery, siliceous rock 365 



7. Greenish, compact, siliceous, slaty shales 250+ 



Total 2,150+ 



Below No. 7 there are more shales and then a series of compact, 

 hard quartzitic sandstones of the Corral Creek formation, as seen 

 south of Fort Motmtain. The sandstones are not well exposed in 

 the Mount Temple section. 



At Vermilion Pass a gray saponaceous, siliceous shale occurs be- 

 neath the basal Cambrian conglomerate, and outcrops of purple- 

 colored shales occur low down on the northeast slope of Boom 

 Mountain. 



On Bath Creek, along the line of the Canadian Pacific Railway, 

 west of Laggan, outcrops of tilted and folded, arenaceous, purple 

 shales occur, and at various points in the broad valley of the Bow 

 the shales and sandstones of the Hector? formation may be seen. 

 Usually, however, the floor of the valley is covered with the gravels, 

 sand, and clays of the drift. 



CORRELATION OF BOW VALLEY PRE-CAMBRIAN ROCKS 

 WITH THOSE OF NORTHERN MONTANA 



The finely arenaceous and siliceous purple, gray, and greenish 

 shales of the Hector formation are of the same general character 

 as those beneath the basal Cambrian conglomerate in Montana,* 

 except that the pre-Cambrian shales in Montana are more distinctly 

 arenaceous. The shales and sandstones of this series extend north 

 from the Montana-Alberta international boundary to about 30 miles 

 south of Crow Nest Pass, where they are cut off by faults that bring 

 the Carboniferous and Cretaceous formations against them either by 

 overlap or faulting. It is highly probable that pre-Cambrian rocks 

 will be found not far north of Crow Nest Pass and west of the 

 known Cretaceous and Carboniferous rocks ; also in the valley of 

 the Kootanie River, east of the Brisco and Stanford ranges. There 



* Bull. Geol. Soc. America, vol. 17, 1906, Algonkian Formations of Montana, 

 p. 3, 2a of section. 



