1899] Barlow— Arch^an Conglomerates. 211 



ice along the base of the diorite cHffs vvhiehhere forms the north 

 side of the valley of Beaver Creek. A search was made, with the 

 result of finding exactly similar strata in place, forming a small 

 band completely enclosed in the intrusive mass and extending 

 completely across lot 13 as well as a short distance east and 

 west into the adjacent lots. Detailed examination revealed 

 much more extended exposures on the hills to the northward of 

 Gilmour Station, situated chiefly on lots 11 and 12 in the 

 XVIIIth concession. 



The so-called conglomerates may be included under two 

 great classes. 



1. Those which have a matrix of limestone or dolomite. 



2. Those in which a greyish, sometimes almost black mica- 

 ceous rock, forms the cementing material. 



The limestones breccias may likewise be subdivided into 

 two classes {a) those which readily show their origin as dynamic 

 breccias and (d) those which more closely resemble ordinary con- 

 glomerates and may, following Van Hise, be called pseudo- 

 conglomerates. (See Plate VII, Fig. i and 2.) Both varieties 

 of these calcareous fragmentals are abundantly represented and 

 are as would be expected most frequently to be met with at or 

 near the line of junction with the intrusive granites, gneisses 

 and greenstones, these places representing areas or zones of 

 extreme disturbance. 



In regard to the material constituting the supposed pebbles 

 they likewise admit of a two-fold division : 



(a) Those which are formed by the breaking apart of what 

 were once fairly continuous bands of the rusty-weathering or 

 greyish gneiss, already mentioned as so frequently and intimately 

 associated with these crystalline limestones and dolomites. 



(d) Those in which a series of approximately parallel dykes 

 of intrusive material, chiefly granite, diorite and amphibolite 

 have suflered the necessary deformation and dislocation. 



The class first mentioned (a) are doubtless the most abun- 

 dantly represented in this district, and a great many of the 

 exposures show almost at first sight their origin as autoclastic 



