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44 NEW YORK STATE MUSEUM t'^ 



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Saratoga. Beneath this was i8o feet of darker colored dolomite i 

 of varying grain, the upper and lower portions through a thickness > 

 of some 50 feet each coarser than the center. The upper part had ' 

 many nodules of crystalline calcite. Underneath this was a recur- ) 

 rence of coarse, light colored beds. This gave rise to the suspicion j 

 that perhaps a fault was crossed here causing a reappearance of 

 the upper beds of the formation. But no suggestion of a fault was , 

 given in the appearance of the drill core, and a careful comparison j 

 of this portion with the upper portion did not show any exact corre- ^ 

 spondence. There was also a greater thickness of the coarse beds 

 here than above. Below, dark beds came in again and the well 1 

 terminated in these. If this section is really unbroken, then the j 

 thickness of the formation is certainly 300 feet and may be con- j 

 siderably more. 



The Hathorn well was 1006 feet deep. After 62 feet of drift 

 the drill entered the Amsterdam limestone. The bottom 231 feet 

 were reported as Potsdam, but the thickness suggests that the 

 Theresa is also included and perhaps the basal Hoyt. Assuming it 

 to represent Potsdam and Theresa, and deducting this thickness and 

 the drift thickness from the total of the well, leaves yet a thickness 

 of over 700 feet for the combined Amsterdam, Little Falls and 

 Hoyt formations. If the bore does not cross a fault this would 

 mean a thickness of from 500 to 550 feet for the Little Falls which 

 is considerably in excess of any known thickness elsewhere pos- 

 sessed by the formation. It is doubtful if it exceeds 350 feet in | 

 the Saratoga region, though it may reach 400, which is as great , 

 a thickness as it is known to reach at any point. 



There is much chert in the formation. Black chert is the most 

 abundant but gray chert is by no means uncommon. The upper 

 beds of the formation are heavily charged with chert in nearly all 

 localities throughout its extent, and Saratoga is no exception to 

 the general rule. The upper bed at the Maple Avenue quarry is 

 full of chert. The lower beds of the formation are also heavily 

 charged with it. These beds are best seen about a mile south of 

 Porter Corners. 



The formation is everywhere exceedingly unf ossilif erous. L i n - 

 gulella acuminata is occasionally found in the lower beds 

 and a few fossils are sometimes to be seen in the upper cherts. Th< 

 most common fossil, however, is Cryptozoon, reefs of which occui \ 

 throughout the formation. This is the only fossil which we hav(- 

 seen in the formation about Saratoga. In most of the formation th<' 



