yOBK mam. MUSEUM 



l\ BGgley, Monty i but, owing to its silicious nature, it 



oly for building stone. It analyzed 



Linn 29.05 



ia 12.8 



id 1 .02 



Alumina -46 



'bonk ari'l 3S.6 



tluble residue 18.04 



The Trenton limestone is exposed about li miles east of the 

 tal, and the BOCtion is very >imilar to that found at Glens Falls, 

 the upper layers being Bomewhat impure and the lower lay 

 showing 8 feet of black limestone evidently of considerable 

 purity. 



Other quarries are at Saratoga Springs and South Glens Falls. 



Schenectady county 1 

 Thi- county is destitute of limestones except a small area of 

 Calciferous in its extreme northwestern corner, and a bit of 

 L er Helderberg in the southwestern portion. Both are of small 

 tent. Limestone is quarried at IlofTmans. 



Schcharie county 2 



This county exhibits a great thickness of Helderberg limestones, 



which have been opened up at Schoharie, Howe Cave, Barnerville, 



•leskill, Middleburg, Sharon Center, Sharon Springs and 



I rry Valley. The general section can be obtained from the ac- 



iit of the Helderberg Limestone formation in another portion 



of the report. 



Al Schoharie and Howe Cave there is a splendid develop- 



at of the lower Pentamerus and Tentaculite members. The 



. which are GO to 70 feet thick, are hard, massively 



v jointed limestones, of bluish gray color. * 

 taculite beds, underlying the Pentamerus, are thin 

 . «lark blue limestones, whose layers vary from 2 to 3 

 .\' ! e and Schoharie their thickness is 40 feet. 



i Vanuxem, I ardni I. :M diat. N. V. 1842. 



a \\ . Geol. Nt diat N. Y. L843. 



