MESOZOIC SYSTEMS ALONG THE PACIFIC 



279 



SCALE IN MILES 

 I 2 3 



; Fig. 17.16. Cross sections in the Similkameen District, British Columbia, Latitude 49, Longitude 

 | 120. 1, Vaseaux fm., paragneiss, schist, quartzite; 3, Koban group, schist, greenstone; 6, Barslow 

 | fm., argillite; 8, Shoemaker fm., chert, some tuff, greenstone; 9, Old Tom fm., greenstone, basalt 

 j flows, sills, bosses, some diorite; 10, altered rocks of dioritic composition; 11a, Osoyoos grano- 

 f diorite; lib, Fairview granodiorite; 12a, hornblendite; 12b, pyroxenite; 14a, Kruger syenite; 



r cordant batholiths, as well as some of the most conclusive evidence of 

 Utoping, may be found in the northern Cascades (Daly, 1912). See Figs. 

 $7.15 and 17.16. 



The igneous bodies generally designated by the names Osoyoos and 

 . Colville batholiths (see map, Fig. 17.13) are really complex associations of 

 | eight plutons. Contact metamorphism is intense near some but almost 

 i absent near others ( Krauskopf , 1941 ) . Detail along the border of the Col- 

 j ville batholith has been worked out by Waters and Krauskopf ( 1941 ) . See 



14b, Oliver syenite; 15, granodiorite; 16a, Oliver granite; 17, Springbrook fm., conglomerate, 

 some sandstone and shale; 18, maroon fm., basaltic lava, some breccia, tuff, conglomerate. 



1 and 3, Carboniferous. 6, 8, and 9, Triassic or older. 11 and 12, Jurassic (?). 14, 15, and 

 16, Jurassic and (or) younger. 17 and 18, Eocene. After Daly, 1912. 



Fig. 17.17. The batholith is a complex plutonic mass that intrudes folded 

 and dynamometamorphosed sedimentary and volcanic rocks of late Paleo- 

 zoic and Triassic age. Along the sharply discordant contact, the wall rocks 

 are much fractured and granulated, but contact metamorphism is slight or 

 absent. The batholith is remarkably heterogeneous, both structurally and 

 petrographically. A central mass of structureless granodiorite grades out- 

 ward into a belt of foliated igneous rock which commonly shows intricate 

 swirling of the foliation. The swirled rocks grade into a peripheral belt of 



