GEOLOGY OF SARATOGA SPRINGS AND VICINITY 79 



mountain now best exposed near the two road crossings, the one 

 just west and the other just south of Bald mountain, near the latter 

 crossing in a quarry. The dolomite in the former outcrop is, on 

 account of the complicated overturned and recumbent fold struc- 

 ture of the limestone belt, apparently separated from the limestone 

 by shale beds (see page 109) and so represented by Walcott. The 

 aspect of the dolomite which also contains considerable chert reminds 

 one of the Little Falls dolomite. It is, however, not to be sepa- 

 rated as a unit from the limestone, for the two were found to be 

 grading iijto each other on the road from Middle Falls to Bald 

 mountain and also along the road south of Middle Falls. One 

 instructive locality, a small quarry alongside the road, at the west 

 foot of Louse hill, furnished the following section in descending 

 order : 



Thin-bedded limestone 

 Massive limestone bed 

 Brecciated limestone with gastropods 

 Dolomite bed with irregular band of limestone in 

 middle, full of narrow chambered cephalopods 

 Dolomite bed 

 Brecciated limestone 



Of the limestone we have seen in one place (west of Louse hill) 

 70 feet in continuous section, with the top and bottom not exposed. 

 It may therefore reach 100 feet in thickness. It is for the most part 

 fine grained, sometimes approaching the dove-colored limestones, 

 light bluish gray in color with many white crystalline spots. In the 

 lower part it contains somewhat arenaceous bands. It resembles 

 some of the limestone of D of the Champlain valley and also some 

 of the Middle Chazy rocks. Emmons referred it to the Calciferous 

 sandrock (Beekmantown). Walcott designated it as Chazy lime- 

 stone in the Bald IMountain section, but stated (1888, page 317) 

 that about 2 miles north of Bald mountain similar rocks contain 

 Trenton fossils. Dale (1889, page 190) also refers to this lime- 

 stone as Trenton limestone but mentions that in some places it 

 may represent the entire Lower Siluric series and should then be 

 regarded as Trenton, Chazy, and Calciferous. On the Schuyler- 

 ville quadrangle the limestone is as the above given fossil lists 

 show, throughout of Beekmantown age. There is, however, no 

 doubt that also in other parts of the slate belt limestone of Tren- 

 ton, or at least Mohawkian. age outcrops. The presence of such 





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3 



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2 feet. 



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3 feet 





