94 RURAL NEW YORK 



the extent to which it is drained and the general 

 lay of the surface, as well as the fineness of the mate- 

 rial and the occurrence of stone. 



The individual kinds or types of soil fall into 

 groups in each of which the types have many charac- 

 teristics in common, such as color, kind of rock mate- 

 rial and arrangement. Such a group of soils forms 

 a soil series. 



The soil conditions of the State may be described 

 by physiographic regions, as already enumerated. 

 The distribution of the different groups and series is 

 best represented by the map in Fig. 17. This should 

 be studied in connection with the relief map of the 

 State (Plate I). 



SOUTHERN PLATEAU 



This region of generally high elevation with deeply 

 dissected valleys is mostly covered by light colored 

 stony soils, formed directly by glacial ice. The un- 

 derlying rocks are predominately gray to black sand- 

 stones and shale with occasionally very thin strata of 

 impure limestone. These are embraced in the Cats- 

 kill group of rocks of the Devonian series. All of the 

 soils of the region are deficient in lime and over large 

 areas this is so pronounced as to be tlie chief limiting 

 factor in the production of large yields of crops. 



All the unglaciated soils are embraced in the De- 

 Kalb series. The stony loam type predominates. 

 The DeKalb soils occur exclusively in the south- 

 western part of the State. In this region the be- 

 neficent effect of the glacial invasion is well illustrated 



