22 Report on Building Stone of New York. 



Lower Helderberg Group. 



This group includes a wide variation in its limestones, and no 

 general statements apply to the several horizons alike. The forma- 

 tion is traced from the Helderberg mountains westward, south of the 

 Mohawk river nearly to Syracuse. The lower beds (Tentaculite) are 

 dark-colored, compact, thick, and afford a stone which can be polished. 

 The Pentamerus limestones, in the upper part, furnish a gray, heavy- 

 bedded and strong stone, which answer for heavy masonry. Quar- 

 ries in the Lower Helderberg group are opened in the Schoharie valley 

 at Cobleskill, Cherry Valley and in Springfield, Otsego county. 



The quarries near Hudson, in Becraft's mountain and the quarries 

 near Catskill also are in it. 



Upper Helderberg- Group. 



Under this head there are building stones in the several limestone 

 formations. Of these the principal are the Onondaga and Corniferous 

 and the Seneca blue limestones. The noted " Onondaga gray lime- 

 stone," of Onondaga county, belongs in this group. The Union 

 Springs, Waterloo, Seneca Falls, Auburn, Le Roy, Williams ville and 

 Buffalo quarries are Upper Helderberg. The Kingston, Ulster 

 county, limestone also belongs here. 



There is a great diversity in the limestones which are quarried in 

 these localities and from this geological group. The Onondaga gray 

 limestone is coarse-crystalline, and contains coralline fossils ; and 

 makes a beautiful stone for fine cut ashlar work or for ornamental 

 and decorative uses. The cherty or corniferous beds are dark-col- 

 ored, hard, and do not dress well, and answer for common work only. 

 The Seneca blue limestone dresses well and is a fairly good building 

 stone. 



As a supplement to the limestones the quarry in calcareous tufa at 

 Mohawk, in the Mohawk valley, should here be mentioned, although 

 the quarry is of no importance and there is no great outcrop for 

 much work in it. 



It is proper to refer to the division of Fragmental Rocks, the stone 

 which occur in the Quaternary formation, particularly and chiefly in 

 the Glacial Drift. This drift is found in all the counties of the State 

 and in nearly all of the towns, overlying the older rocks. But it is 

 unimportant as a source of building stone at the present time. In the 

 earlier history of the country many stone buildings were constructed 



