342 



GEOLOGY OF OHIO. 



solution of the question, " Do Hamilton fossils extend through the whole 

 of the blue limestone ?"• — a question propounded by the Director of the 

 Survey for the purpose of testing the evidence. It is deemed best here to 

 present a general section of the rocks of Paulding and Defiance counties, 

 in order to express clearly the position of the beds that have furnished 

 the writer the only Hamilton fossils found in north-western Ohio. This 

 section agrees in all its details with that of Delaware county, except the 

 attenuation here of the Olentangy shale of Delaware county. Indeed, 

 this shale, which in the Report of Progress for 1869 is regarded as Ham- 

 ilton, is seen to be entirely wanting in most places in Defiance county, 

 the thin, tough black slate layers lying immediately on the hard beds of 

 the Tully limestone : 



General Section of the Rocks op Paulding asd Defiance Counties. 



No. 1. Black slate. {Huron shale of the Ohio reports 



2. BluiBh shale. (Olentangy shale of Delaware county.) 



3. Blue and blackish limestone ; hard and silicions. (The 



TtiUy limestone of New York State.) 



4. Blue limestone ; the whole, including the lowest ob- 

 served part of this, holds Hamilton fossils. (The 

 Hamilton limestone of New York.) 



Saccharoidal, very fossiliferons limestone. (The Delhi 

 beds of Delaware county ; the Curniferous limestone 

 of New York.) 



Buff, magnesian limestone ; the upper half is 

 thin-bedded, (The Onondaga limestone of 

 New York State.) 



1. Quartzose sandstone ; con- 

 glomeratic in Delaware 

 county. (The Oriskany of 

 New York State.) 



8. Heavy-bedded magnesian 



limestone. (Phase No, 2 

 of the Waterlirae of 

 Ottawa county.) 



9. Irregular and wavy-bedded, 



compact limestone. (Phase 

 No. 3 of the Waterlirae of 

 Ottawa county.) 



