REPORT OF THE CHIEF ASTRONOMER 397 



SESSIONAL PAPER No. 25a 



orthoclase, microcline, and abundant plagioclase (averaging labradorite) — all 

 enclosed in a light-coloured, argillaceous base. The sandstone has thu9 the 

 composition of a bedded arkose. 



The argillite interbeds are thin-layered, often papery. The colours are 

 light to dark gray and blackish, the variation depending on the relative con- 

 tent of carbonaceous matter. The lighter coloured shales are rather highly 

 silicious and weather almost white. 



A bed of coal is reported to have been found near the base of the sand- 

 stone in the canyon section but it was not accessible at the time of the writer's 

 Visit to the section. No reliable statement as to its thickness could be obtained 

 from the settlers, but it is doubtless thin; on account of the fact that the area 

 of the enclosing sandstone is very small, this coal could have little practical 

 importance unless it were of relatively great total thickness. 



Reviewing the characteristics of the different members of the formation, 

 we are prepared to find that the fossils contained indicate a fresh-water origin 

 for this series of beds. Such is, in fact, the most probable view of the Kettle 

 River formation. Some horizons (the paper-shales particularly) suggest lacus- 

 trine sedimentation; others suggest fluviatile sedimentation. As the average 

 lake is an enlarged river-channel, so the larger rivers in flood are temporary 

 lakes. It is here very difficult, if not impossible, to distinguish in most of the 

 beds those which were laid down during river-floods from those laid down on 

 the floor of a permanent lake. 



Geological Age. — The Kettle River beds are seldom entirely free from traces 

 of fossil plants and at a few horizons useful material was collected during the 

 seasons of 1902 and 1905. (Plate 36.) The different collections have been grouped 

 under the locality numbers 250 (where specimens were taken in both years), 271, 

 1001 and 1007. These localities are marked on the MS map. No animal remains 

 were found at any point, though special search was made for them at the many 

 ledges exposed. The plant remains were sent to Professor D. P. Penhallow of 

 MeGill University, who reported at length on the collection. His paper was 

 published in the Transactions of the Royal Society of Canada, 1908, and is 

 reprinted as Appendix B of the present report. The reader is recommended to 

 read this important study of the British Columbia fossil plants recently 

 collected; it will be found that the treatment of the Kettle River fossils is 

 specially full. Four new species belonging to the genera Picea, Pinus, and 

 Ulmus are named and described. The present writer is under deep obligation 

 to Professor Penhallow for the special pains which he took with this 

 set of collections. His report is of immediate value in the present connection 

 since it contains a full discussion of the Kettle River flora as compared with 

 the floras of the Similkameen and other formations of the west. As a result 

 of his work Professor Penhallow concluded that the Kettle River beds should 

 be referred to the Oligocene and so they have been mapped in the accompany- 

 ing sheet. Their general correlation with the Tertiary formations of the 

 United States and Canada is also discussed in the paper by Professor Pen- 

 hallow. 



