786 W. G. FOYE 



However, C. H. Smyth, Jr. 1 and H. P. Cushing 2 now consider 

 them igneous. 



The gneisses of the Highlands of New Jersey may be described 

 in similar language. These are considered by W. S. Bayley 3 and 

 C. N. Fenner 4 to be sediments invaded by granite. 



G. M. Dawson writes as follows concerning the Shuswap Ter- 

 rane of British Columbia: 



The Shuswap rocks proper evidently represent highly metamorphosed 

 sediments with perhaps the addition of contemporaneous bedded volcanic 



materials These bedded materials are, however, associated with a much 



greater volume of mica-schists and gneisses of more massive appearance, most 

 of which are evidently foliated plutonic rocks, and are often found to pass into 

 unfoliate granites. The association of these different classes of rocks is so 

 close that it may never be possible to separate them on the map over any 

 considerable area 



A distinct tendency to parallelism of the strata or foliation with adjacent 

 borders of the Cambrian system has been noted in a number of cases. This 

 might imply that the foliation was largely produced at a time later than the 

 Cambrian, but materials of some of the Cambrian rocks show that the Shuswap 

 series must have fully assumed their crystalline character before the Cambrian 

 period. It seems, therefore, probable that the foliation of the Shuswap rocks may 

 have been produced rather beneath the mere weight of superincumbent strata than 

 by pressure of a tangentical character accompanied by folding. 5 



R. A. Daly, in a recent report on this same series, states that 

 it has been .injected by innumerable sills and laccoliths. He 

 concludes : 



The extraordinary prevalence of sills and other concordant injections is 

 explained by the extreme fissihty of the Shuswap sediments and greenstones. 

 This feature is due to static metamorphism. 6 



Two hypotheses are offered, therefore, to explain the parallel 

 banding of pre-Cambrian rocks. In the Haliburton-Bancroft 

 area, Adams conceives that, in the process of intrusion by magmatic 



1 N.Y. State Mus., 41st Ann. RepL, II (1899), 469-97. 

 'Bidl. No. 115, N.Y. State Mus. (1907), 451-531. 



3 U.S.G.S., Raritan Folio, No. 191. 



4 Journal of Geology, XXII (1914), 594 ff . 



5 Bull. Geol. Soc. Am., XII (1901), 63-64. 



6 Ann. Rept. Dept. Mines, Can. Geol. Surv. (1911), 3-12. 



