GEOLOGY. 297 



opment of the Salina formation, with great beds of rock-salt, 

 in Ontario, and the intercalation of the overlying Water-lime 

 beds with fossiliferons strata apparently of Upper Helderberg 

 age. Since that time rock-salt has been discovered at the 

 same horizon by a boring at Wyoming, thirty-seven miles 

 south of Rochester, in New York. After traversing 660 feet 

 of strata representing the Genesee, Hamilton, and Marcellns 

 divisions, 5V0 feet of limestones and some shales, supposed to 

 include the Corniferous, the Water-lime, and part of the Sa- 

 lina, were passed through. Below, at a depth of 1279 feet, 

 in soft shales, was found a bed of rock-salt 70 feet in thick- 

 ness, of which the larger part is said to be pure. The boring 

 was carried downward through the red marls and sandstones 

 of the Salina until the Niagara limestone was reached at a 

 depth of 1562 feet. The whole thickness of the united Sa- 

 lina, Water-lime, and Corniferous formations in this region is 

 thus onty 900 feet. 



Ashburner, of the Second Geological Survey of Pennsyl- 

 vania, finds in the centre of that State, beneath the Lower 

 Helderberg limestones of Lewiston, a series of 580 feet of 

 thinly bedded, more or less argillaceous, limestones, followed 

 in descending order by 375 feet of fossiliferous limestones 

 and slates, which in their turn repose upon the Clinton for- 

 mation, and in part, at least, represent the Niagara ; while the 

 overlying portions are supposed to be the equivalents of the 

 Salina and Water-lime series. The salt and gypsum which 

 were deposited at this horizon in New York and Ontario are 

 thus absent in this part of Pennsylvania. 



Dieulefait, in a late memoir on the deposition of salt, insists 

 upon the fact that the salt deposits of Europe belong to two 

 horizons the one Mesozoie, of the age of the Lias, and the 

 other in the Middle Tertiary. It is to be noted, however, 

 that the strata of these periods are not saliferous in Eastern 

 North America, where the deposition of salt took place in 

 Lower Carboniferous and in Silurian times. It has for some 

 time been known that certain salt deposits in Southern Asia 

 were as old as, or older than, the Salina period; and we are 

 now indebted to Wynne, of the Geological Survey of India, 

 for the following details, contained in a recent account of the 

 Upper Punjaub. According to him the salt formation to the 

 west of the Indus is above the Cretaceous, and probably Eo- 



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