88 
MUSEUM BULLETIN NO. 2. 
Siyeh Formation. Lying conformably on the Kitchener 
formation and passing into it by gradual transition occurs the 
Siyeh formation, which consists of purple and green siliceous 
argillites in beds from 1 inch to 2 inches in thickness. Dolo- 
mites and limestones are present in the middle part of the forma- 
tion. The argillites are characterized by the presence of abund- 
ant mud-cracks and ripple marks. 
Purcell Lava. The Siyeh epoch was brought to a close by the 
outpouring of basalt called the Purcell Lava. This lava consists 
almost entirely of amygdaloidal basalt with small amounts of 
rhyolite and breccia and is the extrusive phase of Purcell Sills. 
Gateway Formation. The lower part of the formation consists 
of alternating bands of massive concretionary siliceous dolomite 
and limestone weathering buff, and massive light grey quartzites. 
These are succeeded by thin-bedded sandy argillites and greenish 
grey siliceous argillites. The sandy argillites weather a light 
buff and are characterized by the presence of abundant casts of 
salt crystals. 
RELATION OF GALTON SERIES TO THE PURCELL 
SERIES. 
The Purcell series of the Purcell range is the western or near- 
shore equivalent of the Galton series and the relations of these 
two series is expressed in the following table. 
Galton series of the Galton range of 
Rocky Mountain system. 
Purcell series of the Purcell range. 
Roosville 
Phillips 
Gateway 
Gateway 
PurceU Lava 
Purcell Lava 
Siyeh 
Siyeh 
Kitchener 
Creston 
Aldridge 
