the Structural Relations of the Huronian. 



229 



GRANITES 



SCHISTS 



PEGMATITE 



failing to find those of another, Barlow erroneously concluded 

 that the latter do not exist. 



However, resting upon the crystalline complex east of Thes- 

 salon as a basement is the great conglomerate described by 

 Irving. This conglomerate contains numerous bowlders of 

 the red and gray granite, of the pegmatitic granite, and of the 

 various crystalline schists derived from the immediately sub- 

 jacent basement com- 

 fig. 2 plex, as well as other 



materials not noted 

 as occurring in this 

 vicinity. The char- 

 acter of this con- 

 glomerate is shown 

 by figure 2, drawn 

 from a photograph. 

 How different this 

 true conglomerate is 

 from the pseudo- 

 conglomerate may be 

 seen by comparing 

 figures 1 and 2. In 

 figure 1 the fragments are all alike and the same as the adja- 

 cent schist, while those of figure 2 have great variety and are 

 more rounded. Also, although not possible to represent it in 

 figure 2, the matrix is fragmental while in the other case it is 

 crystalline granite. 



The line of contact between the true conglomerate and 

 the basement complex across one island is so distinct 

 as to be located to the fraction of an inch. This line is 

 irregular and in one place varies in strike within a foot or 

 two as much as 45° or 50° (see fig. 3). At places upon the 



lower side of this 

 line is the gray 

 granite, at other 

 places are the schists, 

 the two having the 

 relations before de- 

 scribed, and both 

 are cut by the peg- 

 matite- granite. At 

 one place the folia- 

 tion of the crystal- 

 line schist or gneiss 

 abuts perpendicular- 

 ly against the line of 

 contact. Along: the 



FIG. 3 



GRANITES 



SCHISTS 



PEGMATITE 



