RELATIONS OF THE WE WE SLATE. 271 



are close together, so that there is but a sparse matrix. In some cases this 

 recomposed rock so closely resembles granite that it is with difficulty tliat 

 its true character is certainly determined. In cases of doubt, however, the 

 weathered surface enables one to distinguish between the original and the 

 recomposed rocks, as here the granite fragments protrude from the face of 

 the conglomerate. This granite stucco varies up into slate-conglomerate 

 of differing degrees of coarseness, and finally slate is found containing only 

 small pebbles of granite. In some cases, in the finer conglomerate, the 

 particles of the recomposed rock are almost wholly single grains of quartz 

 and feldspar, or are small complex grains of granite. These show a lami- 

 nated arrangement, and in the liand specimen the recomposed rock (PI. X, 

 fig. 1) very closely resembles the original gneissoid granite. As higher 

 horizons are reached the slate and slate-conglomerate pass up into feld- 

 spathic quartzites, novaculites, slates, and graywackes of various hues, 

 similar to those in sec. 23, and finally above them appear the pure vitreous 

 quartzite of the Ajibik formation. In a number of places the actual 

 gradations are seen, and the formation line between the two is somewhat 

 arl^itrarily drawn 



THICKNESS. 



On account of the complicated character of the folding of the slates, 

 gra3nvackes, and conglomerates southwest t)f Groose Lake, it is impossilAe 

 to give even an approximate estimate of the thickness of the formation. 

 Here, adjacent to the shore-line, it is natural to expect it to have a greater 

 thickness than to the eastward, and it is believed that the tliickness is very 

 considerable. In sec. 22 (Atlas Sheet XXXV) there are almost continuous 

 exposures of the slate, all apparently nordi of the northernmost anticline, 

 and all dipping 50° to 60° the same way for a breadth of 1,300 feet. This 

 would correspond to a thickness of about 1,050 feet. To this would neces- 

 sarily be added the thickness of the conglomerate, wliich should appear 

 below the slate and graywacke. This area is, however, near the northern 

 end of a northwest-southeast anticlinal dome, and the slate shows nmch 

 brecciation, well-developed slaty cleavage, and, when studied closely, 

 numerous minor rolls; so it is entirely possible that the real thickness of 



