26 NEW YORK STATE MUSEUM 



south of Syracuse, where it is about 175 feet thick. The maximum 

 thickness represented on the Syracuse area is less than a hundred 

 feet owing to the erosion of the upper layers. So far as known, 

 the Cardiff shales are barren of fossils in the Syracuse area. 



The higher divisions of the Devonic shales do not occur on the 

 Syracuse area but are exposed farther south on the Tully quad- 

 rangle and are described in the bulletin relating to that region.^ 



ECONOMIC GEOLOGY 



The mineral resources of the Syracuse area are varied and many 

 of them important. They include (i) building stone, (2) crushed 

 stone, (3) cement and lime, (4) sand and gravel, (5) gypsum and 

 plaster, (6) clay and shale, (7) salt, (8) peat, (9) marl, (10) soil. 



Many of these products have been mentioned in the preceding 

 pages and most of them have been discussed in previous publica- 

 tions of the State Geological' Survey. The brief account here 

 given will serve as a local summary. 



BUILDING STONE 



All the limestones of the area, including the Onondaga, Helder- 

 berg, Manlius, Rondout, Cobleskill, Bertie, Fiddler's Green (Camil- 

 lus) and the Lockport, have been used to some extent for building 

 purposes. The most valuable of all for structural use is the lower 

 or crystalline division of the Onondaga limestone, locally known as 

 the " gray limestone." The Helderberg and Manlius blue limestones 

 underlying the Onondaga have an extensive use for foundations, 

 bridge piers, retaining walls, stone fences, and as crushed stone for 

 macadamizing highways, for railway ballast, for concrete work, 

 and with the Onondaga limestone for the manufacture of soda ash 

 at Solvay. The underlying limestones, the Rondout, Cobleskill, 

 Bertie, Camillus and Lockport, are all dolomitic and are all inferior 

 to those mentioned above for structural purposes. They are used 

 locally along the outcrops for rough building work for such struc- 

 tures as will not justify the expense of transporting the better stone 

 from a distance. 



All the limestones of the area are suitable for and all have been 

 used for crushed stone, concrete, macadam and railway ballast. 

 The largest quarries producing crushed stone for such purposes are 

 those of the Rock Cut Stone Company in the railway channel 3 

 miles southeast of the city of Syracuse. 



1 i). D. Luther. Geologic Map of the Tully Quadrangle. N. Y. State 

 Mus. Bui. 82. 1905, 



