374: B. K. Emerson — Upper Devonian Rocks. 



The dips are all to the east and the beds are several times 

 repeated by monoclinal faulting and with each reappearance of 

 the qnartzite it is finer grained and more feldspathic. 



The whole series has a slight pitch to the south, so that in 

 Vernon the whole upper series tapers northward and disap- 

 pears ; and then in going eastward from the argillite we pass 

 from the more quartzose conglomerates through muscovite 

 and biotite quartzites to complete gneisses, as in the successive 

 reappearances farther south. 



The most abundant and characteristic fossils are Chemung 

 with several Hamilton forms, so that the limestone, magnetite, 

 and the base of the qnartzite above the limestone may be 

 placed with certainty near the base of the Chemung. That 

 the whole series must go together is, I think, clear from the 

 map and the preceding discussion. The suggestion of Pro- 

 fessor Hitchcock, that the limestone was bounded on both sides 

 by faults* prove true for the west side, but is not true for the 

 east side, and the important deduction made by him that the 

 limestone was greatly newer than all the surrounding rocks is 

 also disproved. 



The argillite, though the oldest rock, is least decomposed, 

 crumpled and cleaved with dull surfaces and full of coal grains 

 and kaolin, in its most eastern exposures showing minute 

 pustules on its slaty surfaces, and at last developing garnet and 

 biotite in some abundance. In the western exposures of the 

 mica-schist series, kaolin could scarcely be detected, and biotite, 

 garnet and staurolite were quite abundant, but almost micro- 

 scopic, while farther east the surfaces show clearly the musco- 

 vite sheen, and the above accessions are abundant and large. 

 In the calciferous mica schist which lies below the argillite the 

 separate muscovite scales are clearly visible to the eye, and the 

 same accessories occur still larger and with a very different and 

 much more complex structure, f 



* 15, p. 315. 



f The note in the former part of this paper at the foot of page 264 should be 

 transferred to page 266. It applies to figure 2. 



