SOIL SURVFA' OF LOUISA COUNTY, IOWA. 21 



These soils occupy level to slightly undulatinj^ prairie. They are 

 similar to tlio Grundy in general appearance, but typically they have 

 a subsoil little heavier than a heavy silt loam and mottling occurs at 

 24 to 30 inches below the surface. In this county the su})soil is 

 heavier and more compact as the series gradually passes into the 

 Grundy. Going north from Lee and Hem-y Counties to Muscatine 

 and more northern counties, the difference l)et\voen the two scries 

 is well marked, but in tliis county tlie separation is ratlier ar})itrary. 

 It was found that tlio Iowa River marks tlie dividing line between 

 the two soils, and accordingly the praii'ie soils of the eastern upland 

 were mapped in the Muscatine series and those of the western upland 

 in the Grundy series. 



The Clinton series is characterized by gray or dark-gray surface 

 soils, underlain by light-brown or yeUowish-brown compact subsoils. 

 The topography is rolling to broken, and surface drainage is well 

 estabUshed. These soils occur in areas that were forested in the virgin 

 state. 



The Tama soils are dark brown, underlain by j^ello wish-brown, 

 moderately friable subsoils. The members of this series occupy roll- 

 ing areas which were predominantly prairie in their natural state. 

 They are intermediate in characteristics between the Clinton, on the 

 one hand, and the Grundy and Muscatine, on the other. 



The Knox soils are brown, with light-brown or yeUow, friable 

 subsoils. The topography ranges from gentlj^ roUing to sharply 

 roUing. These soils are derived from wind-laid material. 



The Putnam soils are light brown or medium brown to a deptli of 

 6 to 12 inches, where they are underlain by a gray layer little if any 

 heavier than the surface soil and extending to a depth of 12 to 20 

 inches. Here there is encountered a heavy, plastic clay, mottled 

 dark drab and yellowish brown. The transition from the subsur- 

 face layer to subsoil is quite abrupt. The lower subsoil is mottled 

 dark brown, drab, and yellowish brown, and is generally hghter in 

 texture than the upper subsoil, though no lighter than the surface 

 soil. The topography of the Putnam soils is smooth. They closely 

 resemble the Grundy, but differ in the presence of the subsurface gray 

 layer and in the slightly lighter color of the surface soil. The one mem- 

 ber of this series mapped in this county is found principally around 

 the heads of drainage ways and where the prairie and forest meet. 



The glacial soil in this county is derived from the Kansan or lUi- 

 noian till according to the part of the county in which it occurs. 

 Only one glacial series, the Lindley, has been mapped in this county. 

 The Lindley soils are generally yellowish brown, ranging from gray 

 to brown, and are typically shallow, the dark silt surface layer seldom 

 extending to a greater depth than 8 inches. They are underlain 

 by yellowish to yeUo wish-brown, or occasionally reddish-brown. 



