176 



GEOLOGY OP OHIO. 



and is hence often referred to as the "bufi" limestone, to distinguish it 

 from the blue limestones below. These ore beds are detached outliers of 

 a great ferruginous sheet which once covered much of Stark and Car- 

 roll and all of Tuscarawas county. Patches of this ore sheet, separated 

 from their connections by the erosion of the valleys of the Sandy, Conot- 

 ton, and Tuscarawas, occur in the isolated hills of Osnaburg and Paris, 

 the only portions of the county geologically high enough to include 

 them. Such being the geological position of this important formation, 

 it can not be expected to be found in any other portion of the county, 

 even though the hills may theje rise to an equal relative or absolute 

 height with those referred to. It is important to bear these facts in 

 mind, in order that time and money be not wasted in useless search for 

 the blackl:)and and mountain ore. 



I subjoin analyst's of the raw and calcined blackband from Robertsville: 



RAW. CAI.CIXEO. 



Water 18.60 



Silica. 31.40 12 .-.S 



Iron, oxide 18.7.5 (i9.;i4 



Iron, carbonate 2.3.14 



Mangaue.se l.iO M. I.t 



Alumina 1.00 T.OO 



Lime, phosphate 0.7'2 'i.^t.j 



Lime, carbonate 0.7r> 



Lime 1.7- 



Magnesia S.^^tj '2.1G 



Sulphur Lis 0.14 



1 SIS'. 30 ili).37 



Metallic iroti -24. '2S 4i-.'J.') 



Ph()S)ihoric acid 0.;!1 1.08 



