80 THE ROYAL SOCIETY OF CANADA 



5. Tête Jaune Cache to the ''Big Bend" of the Fraser. — The following 

 description of the geology of the Rocky Mountain trench near Tête 

 Jaune Cache is given by McEvoy:^ 



"On the southwest side of the valley, opposite Tête Jaune Cache, 

 on Mica Mountain, a great series of mica-schists are found dipping 

 S.45°W., at angles 30° to 50°. This series includes dark glittering 

 mica-schists, easily weathering, thinly foliated garnetiferous mica- 

 schist in massive beds, bands of dark fine-grained micaceous rock 

 apparently of eruptive origin, and layers of fine-grained gneiss which 

 in some instances at least, is certainly intrusive. The whole series, 

 while differing somewhat from the Shuswap series of the southern 

 interior of British Columbia, shows the main characteristics of that 

 series and may be classed as such. The age of this series as given by 

 Dr. Dawson is Archaean. The wide valley intervening between 

 these rocks and those of Cambrian age opposite is covered by super- 

 ficial deposits and hides the line of contact. It would be necessary to 

 assume a great fault along this valley to explain the attitude of the 

 rocks of the Shuswap series, if the apparent dip of these rocks were 

 the real dip of the original bedding, but such is not the case. The 

 rocks are extremely foliated and all trace of the original bedding is 

 destroyed. This foliation is roughly parallel to that seen in the Cam- 

 brian rocks across the valley where the original bedding could still be 

 distinguished. As it was there entirely independent of the dip of the 

 bedding, it cannot here be taken to have any significance in the 

 determination of the thickness of the formation." 



In 1909, Malloch^ made a rapid reconnaissance along the Fraser 

 River from Tête Jaune Cache to Fort George and made the following 

 observations on the geology of the trench in the vicinity of Tête Jaune 

 Cache. "A series of mica-schists, garnetiferous schists, and gneisses, 

 occurring in the mountain range bordering the trough on the south- 

 west, has been referred to the Shuswap group by Mr. McEvoy. These 

 rocks form the upper part of the range from opposite Tête Jaune 

 Cache to the gap of the Rau Schuswap River. Mr. McEvoy^ states 

 that some of the finer-grained gneisses are certainly intrusive. Mica 

 mountain, where Mr. McEvoy got his specimens, was not visited; 

 and elsewhere no rocks were seen by the writer from which this 

 conclusion could be verified either from a study of hand specimens or 

 from the field relations, and the author is disposed to regard the 

 schists and gneisses as metamorphosed sediments. They dip to the 



1 Geol. Surv., Can., Ann. Rept., vol. XI, 1900, p. 38D. 



^Geol. Surv., Can., Sum. Rept., 1909, p. 126. 



^ Geol. Surv., Can., Ann. Rept., vol. XI, pt. D, p. 37. 



