682 GEOLOGY OF OHIO. 



its weathering has given rise to the thin stratum of soil that now covers 

 it. Examples of this sort may be aaen on Eeed's Hill, in Bath township, 

 where the weathering of the Clinton limestone has furnished a very pro- 

 ductive but shallow soil to quite a number of acres. Along the boun- 

 dary of the Lower and Upper Silurian formations, again, little patches 

 of these native soils are to be seen, as at Goe's Station, in Miami town- 

 ship, and on the farms of Franklin Berryhill and Thomas J. Brown, of 

 Sugar Creek township; but the aggregate of all such cases is insignifi- 

 cant, and the statement that the soil of the county is derived from the 

 Drift scarcely requires qualification. 



There is a very important sense, however, in which the soils of Greene 

 county may be said to be native soils. Naked beds of bowlder clay are 

 no more soil than are raw shales or quarry spalls. All can be converted 

 into soils by sufficient exposure to atmospheric influences. In point of 

 fact, the shales that constitute so large a part of gome Ohio formations, 

 and notably of the Cincinnati series, are converted into soils far more 

 rapidly than the bowlder clay. The soils of the county, then, have been 

 formed where we find them by the same slow processes that are required 

 to transform a stratum of limestone rock into soil. It is principally by 

 the process that is termed " weathering " that the stubborn and imper- 

 vious clays of the unaltered Drift are changed into the porous, light, and 

 permeable layer that we call soil. The action of the atmosphere can be 

 easily traced in such cases. There are always present in our Drift clays, 

 grains, pebbles, and bowlders of limestone. In southern and central 

 Ohio they constitute by far the largest proportion of the rocky fragment* 

 of the Drift beds. But limestone is soluble in rain and surface water. 

 These fragments, then, both small and great, are slowly dissolved, their 

 lime being carried away in drainage water, while the sand and clay and 

 iron which made a part of their substance are left to contribute to the 

 soil. Similar changes go oh in other substances in the Drift bed, and 

 the results of all are to open these stubborn clays to air and water, to 

 change their color, to alter their texture, and thus, also, to alter their 

 specific gravity. The incorporation of vegetable matter with the forming 

 soil goes on through all the stages of its growth. Until the proportion 

 of such matter reaches at least 5 per cent, of the whole mass, the clay is 

 scarcely to be called a soil. 



But in the final stages of its preparation, to another division of the 

 living creation a very important office is assigned, one, however, which 

 is seldom estimated according to its real value. The insect kingdom, 

 beetles, ants, earth-worms, etc., bring up from below the surface, for very 

 different objects in the econmy of their several existences, particles of 



