REPORT OF THE CHIEF ASTRONOMER 423 



SESSIONAL PAPER No. 25a 



altered as if by strong orogenic pressures. Somewhat naturally, then, it may be 

 correlated with the Osoyoos batholith. It will be recalled that Mr. Brock 

 ha3 provisionally referred the intrusion of the many granodiorite bodies of the 

 Boundary Creek district to the Jurassic. 



The Kettle River beds are clearly unconformable upon the Bock Creek 

 granodiorite, diorite, and gabbro, and upon the phyllites, limestones, greenstones, 

 and quartzites of the Anarchist series. The discovery of relatively abundant 

 fossils in the Kettle River formation facilitates its final correlation as well as 

 that of the Midway volcanics with their corresponding intrusive phases. 



These various fixed and tentative conclusions are stated in the following 

 "table, which has its quota of essential dotibts: — 



Pleistocene Glacial and Recent. 



("Midway volcanic group (in part) : 

 ,,. Rhomb-porphyries; chonoliths, sills, dikes, and effusive forms 



■*"«*»« 1 • (including "shackanite"). 



\ Trachyte and pulaskite porphyry ; flows, sills, and dikes. 



f Midway volcanic group (in part) : 

 nr ■ Various mica-andesites and hornblendic andesites; porphyrite dikes. 



uiigocene -j Basalt and augite andesite. 



[ Kettle River formation ; sandstone, conglomerate, shale, traces of lignite. 



Unconformity. 



,- . , . . . , C Rock Creek granodiorite ; Osoyoos granodiorite. 



Jurassic {intrusive) ( Rock Creek | abbro and diorite ' 



„ i .. ? fDunite (serpentine). 



(S \ Anarchist series ; phyllite, quartzite, limestone, and greenstone. 



