

LAKE OF THE WOODS—GENERAL CONCLUSIONS. 51 
Pet - also resemble those of the Quebec group, as developed in the Province of 
Quebec, but do not, so far as known, hold serpentines in the region now 
in question. 
103. The conglomerates have been already fully described as to their 
distribution ; they must occur at several different horizons among the 
slaty rocks, but cover the greatest breadth at the narrow part of the lake 
north of the Angle Inlet. The particular series there shown must be 
of immense thickness, and appears to grow thicker when followed east- 
ward. A similar tendency to increase in importance eastward, was 
observed with other belts of these rocks, in different parts of the lake, 
and agrees with their general inconstant character. 
104. Perhaps the most usual form of the conglomerate is that which 
may appropriately be designated Slate Conglomerate. The whole rock is of 
a green colour, varying between the tint of epidote and that of the lighter 
shades of hornblende, and possibly in some instances due to a develop- 
ment of both minerals, though, generally I think to the latter. Where 
a good weathered surface is exposed, the rock is seen to consist of nu- 
ss merous fragments of irregular shape, which in appearance resemble the 
harder parts of the associated slate rocks. These are imbedded in a matrix 
composed of similar compact green material, and joints—which are fre- 
: quent in some localities—cut evenly through both. On a freshly broken 
| surface no clear distinction appears between the fragments and the en- 
closing material, and the rock only differs from the more compact altered 
- schists and slates in its rougher surface of fracture, and a somewhat 
spotted appearance. 
105. Another form of the conglomerate, which has been called by Dr. 
Bigsby and others Greenstone Conglomerate, appears to consist of roughly 
fractured pieces of somewhat crystalline diorite, the whole enclosed in a 
dioritic paste, similar in colour. The fragments in this species are often 
larger, and the rock they compose is very compact. A third variety con- 
sists largely of quartzite and quartzose rocks, angular fragments of which 
are found imbedded in a greenish mass, or sometimes in a base also ap- 
parently of quartzite and of grey and greyish-green colours. 
106. The whole of these rocks appear to be uncertain in their exten- 
sion, and one is sometimes found replacing another seemingly in the 
same strike. They are associated generally with compact dark-coloured 
dioritic beds, which do not show any fragmentary appearance, but which 
are not so coarse in texture as the well characterized intrusive diorites. 
The quartzites also show a tendency throughout this region to run with 




