226 NEW YORK STATE MUSEUM 



Niagara river. The belt east of Oneida county is thin and follows 

 the range of hills in an east-southeast direction parallel with the 

 Mohawk. With the gradual thickening of the beds and flattening 

 of the topography the outcrop widens out rapidly as it approaches 

 the Oneida lake section becoming lo miles wide in Onondaga county 

 and nearly 20 miles on the line of Cajmga lake where the extreme 

 dimensions are reached. Thence west to the Niagara river the 

 outcrop forms a nearly straight belt 7 to 10 miles wide. 



Our knowledge as to the horizon of the salt in the succession is 

 derived entirely from the records of well borings and the few shafts 

 that have been put down to the beds. The data supplied by the 

 wells are not altogether reliable as most of the borings were made 

 by oil well rigs, a method that does not admit of accurate records. 

 The salt itself is not encountered except at some distance to the 

 south of the outcrop where the covering protects it from the seepage 

 of surface waters. 



In exploration the hard cherty Onondaga limestone following 

 the black Marcellus shale is used as a bench mark by which to 

 locate the position of the salt. The top of the limestone is taken 

 rather than the base, as the succession below is variable and the 

 line between the Onondaga and Oriskany sandstone where present 

 or of the Onondaga and Bertie waterlime is not so easily established. 

 It would appear from the various well logs that the salt lies at 

 varying intervals from the bench mark, ranging from a minimum 

 of about 350 feet to a maximum of 900 feet or so. In the same 

 locality within short distances the interval may also show con- 

 siderable variations, as in the group of wells at TuUy where the 

 salt lies anywhere from 492 feet to 556 feet below the top of the 

 Onondaga. The cherty limestone varies from 60 feet thick in the 

 eastern to 150 feet in the western part of the salt district. 



There seems to be no constant position for the salt, further than 

 that it lies in general within the gray shales between the Bertie 

 waterlime above and the Vernon shales below (see diagram p. 95). 

 Its variability in this respect agrees with the gypsum which likewise 

 shows a considerable vertical range. The question arises whether the 

 salt is not actually in the form of lenses rather than beds, analogous to 

 the gypsum which has been quite clearly shown to be in attenuated 

 lenses that succeed each other along the strike and dip of the strata, 

 in places separated by considerable intervals and again overlapping 

 each other. The writer is inclined to view the rapid changes in 

 the horizon, thickness and number of the salt beds as shown in the 

 well records from different localities to be indicative of such structure. 



