4 BULLETIN OF THE LABORATORIES 



cal peculiarities of the .shales are quite uniform, differing in this respect 

 from the interbedded limestones. 



In Preble county, near Fair Haven, a sandy rock intervenes be- 

 tween the Cincinnati and the Clinton Group. It is about two feet 

 thick. In a fragment of rock lying near by and apparently of the 

 same origin, there was the impression of a large aviculoid shell. In 

 Clinton county, near Wilmington, there is another series of sandy 

 stone between the Cincinnati and the Clinton Groups. The lower 

 part consists of quite heavy stone, about five feet of it are exposed, 

 although there may be more. This contains annelid teeth near its up- 

 per courses. These sandy stones are referred to the Medina Group, 

 although there is no paleontological proof to warrant this reference. 

 They do not exist at all in the numerous exposures near Dayton. 



Several years ago my friend, Mr. A. B. Knerr, at that time assist- 

 ant in the chemical laboratory of Wittenberg College, made for me 

 some analyses of the rocks found at Huffman's quarry, southeast of 

 Dayton, and also of one specimen from the Clinton Group, at a hill 

 known as Camp Corwin, east of Dayton. The result is shown in the 

 following table : 



Chemical Analy- 

 sis OF Clinton and 

 Nia(;ara Limf- 



ST"NK. 



V Tj 





Ca C03 

 Relative amounts of CaO 

 Calcium and Mag- CO.^ 

 nesium Compounds. MgO 



iMgCO, 



o O 



S U 



35-03 

 25.03 



•53 



Sand and Clay In 

 gredients. 



SiO, 

 A1,0, 



II '^-7' 



18.2; 



-03 



6.03 

 2.13 



Amount of Iron En- 

 tering into the com- 

 position. 



FeCO, 

 FeO 



FeS.. 



2 60 



•43 



3-48 



3^33| 



6.56 



Miscellaneous Com- 

 pounds. 

 Water contained not 

 calculated. 



Total 



TiO, 

 Na..O 



i.o6| .37 

 trace 



98.88 99-98 



.24 

 trace 



..19 

 trace 



99.98: 99.82I 99-311 9'>-50 



1.29 



iii.66 



•34 



.87 



9>9' 



