

78 NEW YORK STATE MUSEUM 



These faunules demonstrate the Beekmantown age of the Hme- 

 stone and indicate that it is to be correlated roughly to the Fort 

 Cassin beds, which correspond to unknown parts of Brainerd & 

 Seely's divisions D and E. Since, however, this belt of Beekman- 

 town rocks fully corresponds to the Fort Cassin beds, neither in its 

 lithology nor in its faunal aspect or its stratigraphy, we consider it 

 unsafe to correlate it with the Fort Cassin and shall designate the 

 beds as Bald Mountain limestone. 



The fauna of the Bald Mountain limestone is distinct from the 

 Fort Cassin fauna, on the one hand in the entire absence of the 

 coiled nautiloid cephalopods so characteristic of that fauna, and, 

 on the other hand, by the prevalence of striking Eccyliopteri, which, 

 according to Ulrich, are identical with forms occurring in the Cana- 

 dian of Missouri. 



The Bald Mountain limestone can neither be correlated nor be 

 continuous with the limestones and dolomites outcropping at the 

 foot of the Adirondacks only a short distance to the west on the 

 Saratoga quadrangle, since these beds, though formerly referred to 

 the Calciferous or Beekmantown, are now known to represent only 

 the lowest division A, and perhaps part of B, which are separated by 

 a great unconformity from the Beekmantown and are claimed even 

 to belong to another system (Ozarkic of Ulrich). It iS possible 

 that the Bald Mountain limestone finds its continuation 80 miles 

 farther south in the Wappinger limestone in southeastern New 

 York, but the latter belt includes limestones of Hoyt, Beekmantown, 

 and Mohawkian ages, and the name is therefore not applicable to 

 the possible northern continuation of its Beekmantown portion. 



The lower part of this formation consists of dark gray (but sandy 

 gray when weathered), massive, often sandy and also brecciated, 

 practically barren dolomite ^ of which we have seen 40 feet or more, 

 some in beds as much as 6 feet thick. It is well seen in several 

 places, namely, an old quarry on the west bank of the Batten kill 

 half a mile south of Middle -Falls, in an abandoned quarry on a 

 hill at the west foot of Louse hill 2^ miles south of Middle Falls 

 and in a quarry by the road south of Bald mountain. This, like 

 all the limestone and dolomite on Bald mountain, is referred to the 

 Calciferous by Emmons and it is the Calciferous sandrock of Wal- 

 cott's Bald Mountain section. It is in the neighborhood of Bald 



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^\ few sections suggestive of cephalopods and Ophileta were observed in 

 calcareous layers. 



