PRE-CAMBRIAN OF SOUTHEASTERN B.C. 
87 
The argillaceous quartzites are grey to almost black in colour 
on fresh fracture. They weather to a rusty brown, and since the 
argillaceous quartzites are in greater abundance, they give the 
characteristic reddish-brown colour to the formation as a whole. 
The thick-bedded purer quartzites weather to a light grey 
colour. Shallow water features, except some conglomerates on 
Goat river, were not noticed in the Aldridge formation. In 
places, cubes of pyrite were abundant. A fact, worthy of 
emphasis, is that in this region the Aldridge formation is char- 
acterized by the presence of a relatively large number of thick 
gabbro sills called the Purcell Sills. The succeeding younger 
formations contain only a few gabbro sills, and these are relatively 
thin and unimportant. 
Creston Formation. The Creston formation rests conformably 
upon the Aldridge formation. A transition zone 500 feet in 
thickness separates the Aldridge and the Creston formations. 
The latter consists of a well-bedded series of grey argillaceous, 
quartzites, purer quartzites, and sandstones w'ith thin inter- 
calations of argillite. The beds, averaging one foot in thickness, 
are often cemented together so that they form steep cliffs. In 
the western part of the range, in the vicinity of Goat river, the 
quartzites are coarser in texture, and resemble coarse sandstones 
in appearance, while in the eastern part they are finer-grained 
and more argillaceous. In general, the quartzites are grey on 
fresh fracture and weather to a grey colour, which is in distinct 
contrast to the weathering colour of the Aldridge formation. 
When the grey quartzites are impregnated with cubes of pyrite, 
they weather reddish-brown. 
Ripple marks were noted at several horizons throughout the 
Creston formation. Intruded into the formation are a few 
gabbro sills reaching a thickness of 100 feet. 
Kitchener Formation. Lying conformably upon the Creston 
formation and passing into it by gradual transition is the Kitch- 
ener formation, which is composed of calcareous argillites, 
calcareous quartzites, argillaceous quartzites, and limestones, 
in beds whose average thickness is 6 inches. The weathering 
colour is reddish-brown. 
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