10 KENTUCKY GEOLOGICAL SURVEY. 



plain, probably of Tertiary age, according to Campbell, 1 

 with an average elevation above sea of about 1,000 feet. 

 The surface is sufficiently rolling to be well drained. 

 Its largest streams have not, as a rule, cut very far 

 below the general level, though in some places, as along the 

 Kentucky river, precipitous bluffs have been formed. A level, 

 well drained country, if provided with sufficient rainfall, is 

 bound to be fertile ; but if, in addition, the underlying rocks are 

 so constituted that their decomposition provides a soil abound- 

 ing in the elements needed by plant life, it is doubly so. The 

 Trenton limestones which underlie northern central Kentucky 

 furnish these conditions. Their compactness saves them from 

 rapid erosion, yet they gradually decompose into a fine, mellow 

 soil. Hence the rich blue grass region. 



Surrounding this central area is a belt of country varying 

 from 10 to 30 miles in width in which the surface rocks belong 

 to a formation called by Owen siliceous mudroek, by Linney 

 identified as lower Hudson river, later considered the equiva- 

 lent of the Utica slate of New York, and in this paper termed 

 the Eden shales. In this formation clay shale greatly predomi- 

 nates; the limestones, as a rule, are few and not very thick. 

 Hence it will not hold up. It erodes rapidly and produces a h 

 pography in which ridges and hollows are the conspicuous feat- 

 ures. Two centuries ago this land was protected by forests, but 

 with the advent of settlers it became cleared for farms. Too late 

 it wasi found that it required more labor to maintain these farms 

 than they could support, and now much of the land is being aban- 

 doned and allowed to take care of itself. Some of it is reforest- 

 ing itself slowly, other is rapidly finding its way into the Gulf 

 of Mexico. It would seem that the State ought to take these 

 lands in hand and plant them in trees of the valuable kinds and 

 protect these in their growth. It would be an expense to this 



'U. S. Geol. Surv., Geol. Atlas of U. S., Richmond quadrangle, folio 46, 



1898. 



