122 JOSEPH E. POGUE 



micaceous. The beds dip northward at angles of 35° to 60°, indi- 

 cating that the folding is less gentle than to the west. 



In its central portion the Wells Creek development of the Cant- 

 well was again examined in detail. The adjoined section of the 

 lowermost portion in contact with underlying granite indicates the 

 rapid variation in conditions that gave rise to this series. 



SECTION OF LOWERMOST PORTION OF CANTWELL FORMATION 

 NEAR WELLS CREEK 



Schistose conglomerate 15 feet 



Silicified tuff' ' 15 " 



Alternations of schistose conglomerate and schistose graywacke, 

 carrying beds of shattered black slate and lens-like intercalations 



of tuff 50 " 



Dense, light-colored tuff, very hard 5 '' 



Fairly schistose conglomerate, grading into schistose graywacke, which 

 in turn grades into schistose conglomerate; the whole carrying 



pinching and swelling lenticular beds of tuff 15 " 



Graywacke, with lenses of quartzite and of shattered carbonaceous 



slate 30 " 



Fairly massive siliceous conglomerate 2 " 



Graywacke 3 " 



Carbonaceous slate, badly shattered and slickensided 8 " 



Graywacke, slightly schistose 15 " 



Crushed slate and schistose graywacke 5 " 



Graywacke, fairly massive 5 " 



Covered, mostly altered graywacke 20 " 



Schistose and altered graywacke, injected with quartz stringers and 



lenses 10 " 



Granite, exposed 30 " 



Glacial gravels to valley bottom . 



228 feet 



For a few hundred feet above this section the rocks are not 

 exposed; then there appears a narrow bed of shale, bordered 

 by a large barren quartz vein, which shows beneath a heavy 

 somewhat contorted bed of comparatively massive conglomerate 

 composed predominantly of white quartz pebbles averaging three- 



' As shown by the microscope, this rock is composed of small pieces of quartz, 

 with some orthoclase and a very little plagioclase — all distinctly fragmental — set in 

 a dense, microcrystalline ground. 



