233 



Miometres not so °bvious. The Oligocene (?) lavas and 

 sediments dip away from the intrusive on all 

 sides, as if the intrusive were a partially un- 

 roofed laccolith of later Tertiary date of intru- 

 sion. One difficulty standing in the way of 

 full belief in this hypothesis is the advanced 

 shearing and alteration of the intrusive; a 

 similar condition is extremely rare in the 

 post-Oligocene intrusives of the Cordillera. 

 According to a second interpretation the lacco- 

 lith dates from the Triassic, representing a 

 late phase in the eruptivity of that period. 

 On this view the shearing of the intrusive and 

 the deformation of the Tertiary rocks would 

 be explained by a post-Oligocene, orogenic 

 doming of the whole complex of solid rocks. 



14-6 m. Cherry Creek station. — Alt. 1,134ft. (346 m.). 



23-4 km. Here the southeastern contact of the great 

 intrusive is crossed and the line then runs 

 continuously over the Triassic (Nicola) traps 

 (with fossiliferous interbeds of limestone) to 

 Savona (25-3 m. — 40-7 km.). 

 19-7 m. At Munro Siding the "Painted Bluffs," east 

 32 km. of Copper creek across the lake, are in full view. 

 These are composed of brilliantly coloured Ter- 

 tiary volcanic rocks. The Tranquille tuff beds 

 which underlie the basaltic lavas of the Kamloops 

 group, vary from pale buff or dull green to dark 

 red, brown or gray in colour, and are largely al- 

 tered. Plant and fish remains are found in these 

 beds which place them provisionally in the Oligo- 

 cene. The sequence of the lavas and pyroclastics 

 on the north side of the lake is almost identical 

 with that exposed on Savona mountain on the 

 south side. It is thought that the sections are 

 on the limbs of a broad anticlinal dome since 

 bevelled off during a Pliocene erosion cycle. 

 The surface resulting is well preserved on both 

 Hardy and Savona mountains. 



West of Copper creek, on the hillside may be 

 seen the sites of cinnabar mines which have 

 produced 7,000 lbs. (3,175 kg.) of mercury. 

 The cinnabar is associated with small quanti- 

 ties of stibnite and has a calcite-quartz gangue. 

 35069— 9|a 



