BUTLER COUNTY. 399 



The clearing of the valleys and their drainage basins has introduced 

 many elements of change, and the formation of these bottom lands may 

 almost be said to have been interrupted. This sandy bed, to which 

 reference has been made, is akin in composition and character to the loess 

 of European geologists. An excellent example of the formation may be 

 seen in the river banks within the limits of the village of Middletown. 

 It is burned here into a cream-colored brick that answers well for a 

 paving brick, and which is quite extensively used for this service. 



Its composition is shown in the following analysis of a specimen taken 

 at the point above named. (Prof. Wormley.) 



Water combined - 5.20 



Silicic acid 42.30 



Seaquioxide of iron , 3.48 



Alumina 7.52 



Carbonate of lime 23.21 



Silicate of lime 5.09 



Carbonate of magnesia 13.09 



99.89 

 As can readily be judged from such a composition, soils of great fertil- 

 ity are not formed from this deposit, but there can be no doubt that 

 it would serve an 'excellent purpose as a top-dressing for uplands. It 

 is, in reality, a shell marl, and would reward intelligent use very liber- 

 ally. The thickness of this bed has not been found to exceed four feet in 

 any exposures noted. 



There is often associated with the above-named formation a sort of 

 clay from two to four feet in thickness that agrees in physical characters 

 very closely with the "joint clay" of the western valleys. Its com- 

 position is shown in the appended analysis. (Prof. Wormley.) 



Water combined 4.20 



Silicic acid 70.10 



Sesquioxide of iron 5.30 



Alumina 13.90 



Silicate of lime 2.10 



Magnesia, carbonate 1.44 



Potash and soda 3.20 



100.24 



This deposit can be also seen at the point named under the last 

 head. It is, however, less widely distributed through th6 valley. 



GEOLOGICAL SCALE, .ETC. 



The bedded rocks of Butler county belong, with the exception of the 

 very limited area of one or two square miles, to the Lower Silurian, 



