502 DEPARTMENT OF THE INTERIOR 



2 GEORGE V., A. 1912 



lenses from thirty to forty feet thick in the middle and tapering off to nothing at 

 each end. This form of limestone hody is that often assumed when the rock- 

 series in which it occurs has been subjected to powerful squeezing and rolling- 

 out. The carbonate acted as if it were plastic, thinning here, thickening there, 

 according as the lines of force were directed. The material pinched out at one 

 point became accumulated in pods elsewhere. The relations are thus parallel 

 to those found in the Pend D'Oreille series of the Selkirk range. It is little 

 wonder that the traces of bedding have here disappeared. The rock is now a 

 fine-grained, white to light bluish-gray marble, charged with concretions of 

 chert. These concretions are most irregularly distributed, giving no indication 

 of original bedding-planes. The pods are always vertical or nearly so and strike 

 rather faithfully in the direction 1ST. 20° E. 



Other masses of limestone may occur on the slope down to the Skagit 

 river but the thick brush of the slope prevented their discovery, though the out- 

 crops sufficed to show the predominance of the greenstone and quartzite all the 

 way to the river-flat. 



It is not possible to state the relative ages of the different members with 

 confidence. From the analogy with the less disturbed and probably contempor- 

 aneous Chilliwack series on the west slope of the Skagit range (see next 

 chapter), it seems best to believe, as a working hypothesis, that the Hozomeen 

 greenstone and limestone are younger than the principal quartzite (phyllite) 

 gioup and overlie the latter conformably. 



Correlation. — Since the series is so far quite unfossiliferous, the search for 

 its equivalents among the determined formations of the Cordillera is aided only 

 by the analogies of stratigraphic relations and of lithological resemblances. On 

 these grounds the provisional correlation of the series, at least in part, with the 

 Carboniferous Cache Creek series has been made. Hocks which are clearly much 

 like those at the Skagit river have been found by Smith and Calkins in their 

 reconnaissance of the Boundary belt and have similarly been tentatively 

 referred by them to the Cache Creek division. Their description may be quoted 

 at length: — 



' The supposed Cache Creek series, as represented in this district (upper 

 Okanagan valley), comprises both sedimentary and volcanic rocks. Its lower 

 portion consists chiefly of clay slates and graywacke slates, usually of gray 

 or greenish colour, together with some moderately coarse metamorphic sand- 

 stones and fine conglomerates, but comprises no coarse conglomerates. Occa- 

 sionally the arenaceous portions of the series take on the character of fairly 

 pure quartzite. Material of this sort becomes especially abundant near 

 Mount Chopaka. In the upper portion of the series, as developed at Loomis, 

 there are at least two beds of light-gray limestone, whose areal distribution 

 is indicated roughly in the geologic map. -Farther south, to the west and 

 northwest of Riverside, this rock plays a more important role. The western 

 wall of the coulee north of that place is a cliff perhaps 200 or 300 feet high 

 and composed mainly of limestone. 



