Geological Survey of the State of Neio York. 105 



cepted, the group consists generally of argillaceous materials in 

 the lower part, and carbonate of lime in the upper part. " The 

 red shale forms the base or lowest mass of the salt springs found 

 along the course of the Erie Canal in the third district, and has of- 

 ten been confounded with the red sandstone of Oswego and its pro- 

 longation, the sandstone of Rochester and Niagara. The two 

 rocks, being separated by the Protean group, have no connection 

 with each other, nor resemblance, excepting that the same fer- 

 ruginous material colors them both, and both are connected with 

 saliferous sources." This rock "increases greatly in thickness" 

 from east to west, and from a boring in Lenox of two hundred 

 feet, just north of hills of shale two hundred feet high, attains 

 here a thickness of four hundred feet, " yet no where has a fossil or 

 a pebble been discovered in it, or any thing extraneous, excepting 

 a few thin layers of sandstone and its different colored shales." 



The second deposit is an alternation of variously colored shales, 

 contains fibrous gypsum of a reddish or salmon color, and the ex- 

 cavations of wells exhibit the same products as are found in dig- 

 ging for salt water at Abingdon, Yirginia, in a salt valley. No 

 wells of water are obtained in this or the next deposit, on the 

 hills, unless sunk below the level of the water courses, and there- 

 fore no brine springs could be found above this level, owing to 

 the permeable nature of the strata. The only fossil is a small 

 Cytherina. 



The third or gypseous deposit, contains the extensive and val- 

 uable deposits of gypsum in insulated masses, never in layers and 

 beds, in two distinct ranges, and separated generally by the " ver- 

 micular lime-rock of Eaton, the hopper-shaped cavities, and oth- 

 er porous rocks." 



This group affords the only proof that salt has existed here in 

 a solid state, though never has a particle been discovered in the 

 rock, and it is the only known source of the brine springs of the 

 district. 



The vermicular rock is " a dark gray or blue rock, perforated 

 every where with curvilinear holes, but very compact between 

 the holes, some of them lined with a calcareous crust," and one 

 of the porous rocks affording water lime, consists chiefly "of 

 quartzose and carbonate of lime grains," and " passes into a po- 

 rous cellular sponge-like rock, without carbonate of lime, but 

 abounding in organic remains." " The cavities of these porous 



Vol. XXXIX, No. 1.— April-June, 1840. 34 



