149 



direction, and this is invariably parallel with the strike of the 

 beds, which, as already stated, are inclined to the E.N.E., 20° 

 to 40°. The structure is such that any vertical surface cutting 

 across the strike affords the aspect of a normal conglomerate, 

 the pebbles exhibiting no sensible deformation ; while on any 

 surface parallel with the strike, whether in the plane of the 

 beds or cutting them at any angle, there is nothing to suggest 

 the real nature of the rock ; for, viewed in this manner, it 

 shows no trace of pebbles, but only a beautiful schistosity, 

 resulting, apparently, from the interlacing of thin lenticular 

 layers of various colors and diverse composition ; although, as 

 stated, on the cross-section these seeming layers are seen to be 

 rods. 



This curious structure clearly admits of but one explanation : 

 viz., the horizontal force which folded the strata, and operated 

 in a direction at right angles to the strike, has been accompa- 

 nied by a sensibly equal vertically acting force or pressure, and, 

 under the combined influence of these, the beds, and likewise 

 their constituent pebbles, have been squeezed out in the direc- 

 tion of least resistance, or parallel with the strike. Occasion- 

 ally one may see a pebble of epidote or other refractory material 

 which has successfully resisted the drawing or squeezing-out 

 process, and is now enveloped by the lithologic strings resulting 

 from the deformation of the more yielding adjacent pebbles, 

 which are wrapped about it so as to conform closely with its 

 surface. The pebbles are all well rounded, and consist largely 

 of quartzite, though granite, diorite, petrosilex( ?), and 

 chloritic, slaty and epidotic rocks and epidote are represented 

 in their composition. I have seen no pebbles which seemed to 

 have been derived from a micaceous rock ; and for the most 

 part they have a Huronian rather than a Montalban aspect. 

 That the pebbles are real pebbles, and not concretions of any 

 sort, is shown by the forms of those that retain their original 

 outlines, by their varied composition, and by their textures. 



Every pebble is enveloped in a layer of micaceous material, 

 and the original paste is to a great extent replaced by this min- 



