IXTERESTIXO LOCALITIES OF AJIBIK QUAETZITE. 309 



ujjou wliich (iccur tlu' typical exposures o{ the forinatiou. Tliese arc exceed- 

 dlugly precipitous ridges, very rough in detail, the different ledges breaking 

 off with vertical cliffs or with very steep slopes, and eacli large ridge is 

 made uj) of many smaller ones. The roughness would hardly lie exceeded 

 if the ridges were made liy piling up at random a vast number of gigantic 

 blocks, except that the bluffs are somewhat rounded by glacial abrasion. 

 It is difficult to find ridges more fatiguing to cross than these. One is not 

 able to keep his elevation, but after cdimbing one ridge he is obliged to 

 descend into a steep ravine, only to climb another precipitous slope which 

 rises somewhat higher than the first, to ag-ain descend a sharp declivit\'. 



As the formation is directly in contact with the Archean in sec. 2!) and 

 rests upon the Wewe slates in sees. 27 and 28, and the folding was locally 

 severe, nearly all phases of the formation are found. In sec. 29 the basal 

 conglomerate is made up of Archean debris. In sees. 27 and 28 we have 

 the transitional variety between the Wewe slate and the Ajibik quartzite. 

 Here in the quartzite are interstratified novaculites, slates, and graywackes. 

 Certain of the (piartzites in areas of i-elief were ])ut little aftecte<l by 

 dynamic forces, being ordinary fresh quartzites. Others were fractured 

 extensively in both a major and a minor way, thus producing the veined 

 cherty quartzites. In other places the fracturing went so far as to pro- 

 duce a dynamic breccia exactly similar to breccias in sec. 22 (p. 308). 

 In a number of places also the fracturing resulted in the production of 

 spheroidal-looking fragments, which are set in an iron-stained matrix,, 

 thus giving- a very conglomeratic appearance. At numerous places in the 

 graywacke-like phases a schistosity developed as a result of the mashing, 

 while in the overlying beds of purer quartzite the pseudo-conglomerates or 

 breccias were produced. We thus have at first sight a vertical schistose 

 rock overlain by a conglomerate which occasionally bears fragments of the 

 schist. The appearance of a stractural break was so great that at a first,, 

 and even a second, examination it was confidently believed that there was- 

 here a great unconformity between a schist series and a quartzite-conglom- 

 erate series; but a detailed and close examination left no doubt that the 

 peculiar phenomena were the different effects of dynamic forces in an argil- 

 laceous and a nonargillaceous rock — in the first, flowage and schistosity 



