Kraus — Occurrence of Celestite near Syracuse, JV. Y. 35 



County, is given as a locality for celestite by Beck and Whit- 

 lock, there is little doubt in my mind but that the investi- 

 gators, mentioned above, had encountered specimens of the 

 same character as those shown in figs. 7 and 8, and that the 

 cavities and " impressions " were once filled by the mineral 

 celestite, which was removed in the manner already referred to. 



The third type of dissemination, referred to above, that 

 is, in the form of small circular particles, as illustrated by 

 fig. 5, is exceedingly instructive. When a rock which con- 

 tains celestite in this form of dissemination is leached, it gives 

 rise to a rock which appears as though it were worm-eaten. 

 The lower portion of figure 5 shows the effect of such leach- 

 ing and possesses a distinct porous structure. There is a very 

 striking similarity between such a rock and the so-called " Ver- 

 micular Limestone " of Prof. Eaton and the older reports. 

 This resemblance is shown very clearly in figs. 4, 5, 6 ; figs. 

 4, 6 being the so-called " Vermicular Limestone." 



As regards the character of the rocks of the upper portion 

 of the Salina, which contain the celestite, and which to some 

 extent comprise the vermicular limestones, Luther* says: 

 " The gypseous shales consist of fine-grained magnesium or dolo- 

 mitic limestones in thin layers, masses of gypsum and gysif- 

 erous shale in two courses, separated by a bed of limestone 

 forty to fifty feet thick. In the thicker and more compact 

 layers of limestone, freshly broken blocks show the rock to be 

 very dark, almost black in the interior, but after exposure the 

 color changes to an ashen gray or medium dark drab, some- 

 times showing a slight pink shade. It is very much like 

 hydraulic limestone in appearance, but the proportion of clayey 

 admixture is so large as to injure or destroy its cohesive quali- 

 ties, in the middle and lower beds it is frequently more or 

 less porous or cellular. The cavities are sometimes an inch or 

 more in diameter, very irregular and ragged in shape, and 

 lined with a fine brown dust. When of this character, they 

 are very unevenly distributed through the rock and most fre- 

 quently are found on the surface of a layer or opening into a 

 joint." (Compare with figs. 7, 8.) 



" In other layers, the cavities are found to be much more 

 numerous, occupying in the aggregate nearly one-half the 

 space of the rock, and having the form of circular cells, with 

 the diameter ranging from a quarter of an inch down to a 

 needle-point. Usually the cells in a particular layer of lime- 

 stone have a considerable degree of uniformity in shape and 

 size, but occasionally the contrary is the case. They are smaller 

 in the lower beds. These cellular limestones are the ' Ver- 

 micular Limestones ' of the older reports." See figs. 4 and 6. 



* Luther, Economic Geology of Onondaga County, 264. 



