618 GEOLOGY OF OHIO. 
ries are known as the old state quarries, because the material was used 
in many constructions on the National road. The quarriesare large, but 
the stone from them is used chiefly in building cellar walls, foundations, 
and other rough work of a similar nature. 
Two miles west of Springfield are situated four quarries which 
furnish similar stone, that is used in Springfield, Dayton, Urbana,:Lon- 
don, and Marysville. In all of them the cap-rocks are burned into 
lime, and the larger portion of the profits results from its sale. 
In all cases it is the overlying Guelph beds which are burned, as 
the courses of building stones contain a considerable percentage of silica 
and alumina, and cannot be converted into good lime, although some of 
this material makes a fair cement. The lime product of these quarries 
finds its way in small quantities as far as New Orleans. Itis mild, cool, 
and strong, and also very white. There is no trouble in laying seven 
bricks with one spreading of mortar, and skillful workmen can lay 
twelve bricks with one spreading. The superior quality of this lime is 
worthy of note, since it is ordinarily considered that the value of lime 
is diminished by the presence of magnesia. 
The composition of the Springfield limestones is shown by the 
following analyses of the middle and upper beds in Mr. Frey’s quarries 
near Springfield. These analyses were made by Professor Wormley for 
the Report on the Geological Survey of Ohio: (a) 
Middle bed. Upper bed. 
Calcinmhcarbonatemecnccnes scene etereeeencceer 54.70 54.70 
Magnesiumy carbonatelec.ccscssisecenyenecesecesceesceceess 44.93 42,37 
Alumina and iron sesquioxide ......... cececscecereneee 0.20 1.00 
SIN GCEOUS IMAtbE Hm oeciuesceuesecuseseae et eoskn cuetoneceoneate 0.10 1.50 
Totals cies ietis sesssvseshaeotened cece aaneueanat pata cenaes 99.93 99.57 
It is thus seen that the rocks are very nearly typical dolomites. 
They vary somewhat in composition, but not so as to at all influence 
their value as building stones. They possess an open and porous struc- 
ture, and are incapable of assuming a polish or being used for ornamental 
purposes. In their microscopic structure they are seen to be of the 
erystalline granular type, the fossiliferous character being obliterated 
from the microscopic structure, although fossils are not rare in the rock. 
The Yellow Springs quarries produce a magnesian limestone which 
(a) Geological Survey of Ohio, Vol. I, Parti, p. 474. 
