REPORT OF THE CHIEF ASTRONOMER 87 



SESSIONAL PAPER No. 25a 



the Commission. The exposures are here fairly good but are not extensive 

 enough to show the full thickness or relations of the formation. (Plate 12.) 



The rocks consist chiefly of light to rather dark bluish-gray, often sandy, 

 ■clays. In these there are numerous interbeds of hardened, light-gray sandstone, 

 varying from two inches to a foot in thickness. The sandstone is very often 

 characteristically nodular, with many concretions. A few seamlets of lignite up 

 -to 2 mm. in thickness and a few small, woody stems were observed in the clays. 

 The latter are usually very homogeneous and have the look of lake deposits. 



At the river not more than 250 feet of different beds were actually seen, 

 but it is probable that the total thickness represented in this section exceeds 

 500 feet. Ten miles down the Flathead valley, near the mouth of Kintla creek, 

 the Kintla Lake Oil Company has drilled through 700 feet of soft ' shales ' and 

 sandstones bearing at intervals thin seams of coal. It is likely that these 

 rocks form the southern continuation of the sediments at the Boundary line. 

 Otherwise there is at present no hint as to the full extension of the lake beds. 



Both clays and sandstones are at several horizons moderately fossiliferous. 

 The fossils consist of small and extremely fragile shells. These have been 

 examined by Dr. T. W. Stanton, who reported the collection to 



' consist entirely of fresh-water shells belonging to the genera Sphae- 

 rium, Valvata (?), Physa, Planorbis, and Limnsea. Similar forms occur 

 as early as the Fort Union, now regarded as earliest Eocene, but there 

 is nothing in the fossils themselves to prevent their reference to a much 

 later horizon in the Tertiary, because they all belong to modern types 

 that have persisted to the present day, though it should be stated that their 

 nearest known relatives among the western fossil species are in the Eocene.' 



Dr. Stanton lists the species as follows: — 



Sphaerium sp. Belated to Sphaerium subellipticum, M. and H. 

 Valvata (?) sp. Besembles Valvata subumbilicata M. and II. 

 Physa sp. 



Planorbis sp. Belated to Planorbis convolutus M. and H. 

 Limnwa sp. 



For convenience this group of Tertiary beds may be called the Kishenehn 

 formation, the name being taken from that of the neighbouring creek. The 

 same formation had been discovered near the mouth of the Kishenehn by 

 Dawson who, in 3885, wrote: — 



' Tertiary rocks resembling those assigned to the Miocene in the central 

 platen region of British Columbia, were met with in one or two small 

 exposures in the bed and banks of the river, but poorly displayed and much 

 disturbed by slides. They consist, so far as seen, of hard pale clays and 

 sandy clays. It is probable that they underlie a considerable part of the 

 width of this great flat-bottomed valley, though their extension to the north 

 and south is quite indeterminate.'* 



* G. M. Dawson, Ann. Eeport, Geol. Surv., Canada, 1885, Part B, p. 52. 



