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 
Niagara Lime- 
stone. 
Chemical 
Substance 
Contained. 1 
' 1 
Niagara 
Shale. 
Dayton 
Limestone. 
Beavertown 
Marl. 
Clinton 
Dark Red. 
Clinton 
Light Red. 
Clinton 
Dark Green. 
Camp Corwin 
Clinton. 
Relative amounts of 
Calcium and Mag- 
nesium Compounds. 
Ca Co., 
CaO 
CO, 
MgO 
MgC03 
46.22 
93-23 
26.36 
31-27 
14. II 
97 - 7 ^ 
97-83 
65.14 
35-03 
25.03 
•53 
LT38 
4. CO 
.22 
•75 
1 1 . 1 5 
Sand and Clay In- 
gredients. 
SiO., 
Al-Pa 
17-83 
8.79 
1.95 
18.27 
.^• 5 .^ 
1.03 
.28 
8.27 
2.86 
6.03 
2. 13 
Amount of Iron En- 
tering into the com - 
position. 
FeCO., 
FeO 
Fe-Pg 
FeS., , , 
2 60 
•43 
3-48 
.60 
.21 
3-33 
1.29 
28.66 
6.56 
Miscellaneous Com- 
pounds. 
Water contained not 
calculated. 
Total 
K ,0 
PPs 
TiO.,’ 
Na.p 
1.06 
•37 
trace 
•72 
.22 
trace 
•24 
trace 
1.19 
trace 
•34 
.87 
.22 
trace 
trace 
98. 88 
99.98 
99.98 
99.82 
99-31 
98.50 
99.91 
