REPORT OF THE DI^CTOR AND STATE GEOLOGIST 1903 109 



all the southern quarries, and there is no reason to doubt that 

 the plaster series belongs in the covered space between no. 2 and 

 4, widened probably by the local easterly dip mentioned above, a 

 position to which, in the absence of any local irregularities, it 

 would be unhesitatingly assigned by any geologist. 



There is then no doubt that the gypsum deposits here form a 

 part of the fossiliferous .series, lying above the beds containing 

 Eurypterus, Leperditia alta, Nucleospira ventricosa and Meris- 

 tella Msulcata, and below, or in close connection with beds con- 

 taining well marked fossils of the Pentamerus and shaly lime- 

 stone horizons of the Lower Helderberg. It should also be 

 borne in mind that, apart from the gypsum beds, the entire sec- 

 tion from the lake level to the Oriskany sandstone, is made up 

 of drab limestones with frequent blue seams, sometimes of con- 

 siderable thickness, as in no. 5. iSome of these limestones, both 

 at the bottom and top of the series, are highly laminated, show- 

 ing thin layers of slightly different colors, and nearly all hold 

 a considerable amount of impurities. 



There is indeed, even if w^e set aside the fossil evidence now 

 gained as to geological age, no such lithological change in the 

 limestones as to warrant the reference of the lower portion of 

 them to the Salina period, and the upper part to the Lower 

 Helderberg. Nor is it likely that any such reference would ever 

 have been made had it not been for the presence of the gypsum 

 deposits. These deposits in the regions both east and west of 

 Cayuga county appear, from the State reports, to occupy a 

 pretty definite place in strata hearing intimate relations with the 

 shales of the salt group; to occur in irregular masses inclosed in 

 marly shales whose lamination they sometimes share and some- 

 times disturb ; and to be divided often into two " ranges " by a 

 peculiar porous or vesicular lime rock, or by shaly limestones, 

 holding indications in hopper-shaped accretions of the action of 

 saline waters. It was natural, therefore, in the absence of any 

 evidence to the contrary, that the occurrence of gypsum in any 

 additional locality not obviously removed from its usual horiz?on 

 should lead to the reference of both gypsum and the accompany- 

 ing strata to that horizon. A brief description of the gypseous 

 series here however will show, I think, that its structure bears 

 no very close resemblance to that of the gypsum of the Salina 

 period; that its character is intimately related with that of the 

 accompanying limestones; and that both character and structure 

 tend to indicate for it a different geological horizon, if not a 

 different origin from that of most of the other gypsum deposits. 



It may be said at the outset that the gypsum deposits of this 

 region are not irregular masses: they have no relations there- 



