AMERICAN GEOLOGY DECADE <>E 1830-1839. 337 



granites, gneiss, and mica-slate, this being succeeded by a wide belt 

 (colored blue) of transition slate, graywacke, and graywacke slate, and 

 this, in its turn, by a broad band of sandstone (colored red) extending up 

 as far as Westmoreland County, New Brunswick. The broad belt of 

 trap rocks along the southwest shore of the Bay of Fundy was colored 

 green. Important beds of iron ore were indicated in the transition 

 slate and of coal in the red sandstone. These districts were described 

 in considerable detail, and attention was called to the fact that the 

 different formations corresponded in direction and general character 

 with those of the United States. 



Gesner's ideas regarding the uplifting of strata and the causes thereof 

 were not at all in advance of his time. Thus writing of the position 

 of the slate: 



The strata are variously inclined, and in some cases much twisted and broken; 

 but generally they are so placed as to support the opinion that the primary rocks 

 under their southern side have been uplifted by some violent and sudden move- 

 ment which has thrown the neighboring slate in its present leaning, and often 

 perpendicular, position. 



The iron ore of the South Mountains he regarded as of aqueous 

 origin, such being demonstrated by the presence of the marine fossil 

 shells which it contained. Their presence, however, he was unable to 

 explain. 



From whence came these shells, and by what mighty convulsions and changes 

 in this globe have their inmates been deprived of life and incarcerated in hard, 

 compact, and unyielding rocks? By what momentous and violent catastrophe have 

 they been forced from the bottom of the ocean, where they were evidently at some 

 former period placed, to the height of several hundred feet above the level of the 

 present sea, and even to the tops of the highest mountains? 



And further on: 



It is evident that the slate and ore containing the shells already mentioned were 

 once at the bottom of an ancient sea. * * * By some mighty revolution the 

 ground occupied by them has been uplifted and their native submarine possessions 

 converted into slate, and even iron ore. 



The fact that some of this iron ore is magnetic was regarded by 

 Jackson and Alger as due to the presence of trap rock. Gesner, how- 

 ever, considered this as not probable, and called attention to the fact 

 that the trap rocks are placed in a situation indicating a date much 

 later than the New Red sandstone upon which they rest. 



Notwitostanding the crudity of his notions as to the manner in 

 which the fossil remains had become entombed, Gesner possessed very 

 advanced ideas concerning their value for correlation purposes. This 

 is shown in his discussion of the slate range extending from Yarmouth 

 to the Gut of Canso. The fossils found therein, he felt, had an exist- 

 ence coeval with the original stratification. 



NAT MUS 1904 22 



