318 COUNTY AND KEGIONAL GEOLOGY. 



of the inhabitants for all purposes for which common stone 

 is used, and also for lime. An excellent quality of the 

 latter may be prepared from almost all the stone found in 

 the county. The other resources, so far as at present known 

 or developed, are its moderate supplies of wood-fuel and 

 its universally fertile soil. 



According to the views expressed in another part of this 

 report in relation to the relative position of the coal-bearing 

 strata, it may be reasonably hoped that coal may be dis- 

 covered in almost any part of Clarke county by deep mining. 



5. DECATUR COUNTY. 



Boundaries and Area. Decatur county is the most south- 

 easterly one of those grouped under the designation of 

 Southwestern Iowa. It is bounded on the north, east, and 

 west respectively by Clarke, Wayne, and Ringgold counties, 

 and on the south by the southern boundary of the State. Its 

 outline is nearly that of an equilateral parallelogram, being 

 twenty -four miles from its eastern to its western boundary, 

 and a little more than twenty -two miles from north to south. 

 Consequently, it contains about five hundred and thirty square 

 miles, or about three hundred and thirty-nine thousand, two 

 hundred acres. 



Drainage and Surface Characters. The surface of Decatur 

 county possesses greater diversity than the average of south- 

 western Iowa. This diversity is produced both by the 

 considerable depth of its valleys, and by the unusual propor- 

 tion of woodland. The latter feature of its surface is all the 

 more striking from the fact that the surfaces of the two 

 counties adjoining, upon the east and west are almost wholly 

 prairie. 



By referring to the sections farther on, which illustrate the 

 exposed strata of this county, it will be seen that a 

 considerable proportion of them are of a shaly and clayey 

 character, such as would yield readily to disintegration and 

 erosion. This lithological character of its strata has pro- 

 duced its effect upon the physical features of the surface in 



